|Year : 2016 | Volume
| Issue : 5 | Page : 2-56
International conference on radiation research: Impact on human health and environment (ICRR-HHE 2016) and first biennial meeting of society for radiation research 'Feb. 11-13, 2016'
|Date of Web Publication||29-Feb-2016|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. International conference on radiation research: Impact on human health and environment (ICRR-HHE 2016) and first biennial meeting of society for radiation research 'Feb. 11-13, 2016'. J Radiat Cancer Res 2016;7, Suppl S1:2-56
|How to cite this URL:|
. International conference on radiation research: Impact on human health and environment (ICRR-HHE 2016) and first biennial meeting of society for radiation research 'Feb. 11-13, 2016'. J Radiat Cancer Res [serial online] 2016 [cited 2020 Sep 19];7, Suppl S1:2-56. Available from: http://www.journalrcr.org/text.asp?2016/7/5/2/177654
Abstract ID 0001
Development of Gamma-Tocotrienolas Radiation Countermeasure for Acute Radiation Syndrome
Vijay K. Singh, 1,2 Martin Hauer-Jensen 3
1 F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA; 2 Armed Forces Radiobiology Research Institute, Bethesda, MD, 3 University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, AR, USA
The search for treatments to counter potentially lethal radiation injury has been underway for the past several decades, resulting in multiple classes of radiation countermeasures. However, to date only granulocyte colony-stimulating factor (G-CSF) has been approved by the United States Food and Drug Administration (US FDA) for the treatment of acute radiation syndrome (ARS). Gamma-tocotrienol (GT3) has demonstrated strong radioprotective efficacy in the mouse model suggesting its evaluation in a large animal model. In this study, we evaluated pharmacokinetics (PK) and efficacy against different doses of cobalt-60 gamma-radiation (0.6 Gy/min) using the nonhuman primate (NHP) model. PK results demonstrated increased area under the curve with increasing drug dose, and half-life of GT3. GT3 treatment was able to reduce group mean neutropenia by 3 - 5 days and thrombocytopenia by 1 - 5 days. At 5.8 and 6.5 Gy total body irradiation, GT3 treatment completely prevented thrombocytopenia. The capability of GT3 to reduce severity and duration of neutropenia and thrombocytopenia was dose dependent; 75 mg/kg dose was more effective than 37.5 mg/kg post 5.8 Gy irradiation, however high dose GT3 administration (75 mg/kg) was associated with adverse skin effects (small abscess). A single injection of GT3 without supportive care was comparable to a recently published report using multiple doses of G-CSF with supportive care in terms of improving hematopoietic recovery in the NHP model. GT3 treatment of irradiated NHPs caused no significant difference in animal survival in our study, however, low mortality was observed in untreated control groups as well. The data from this study further demonstrates the hematopoietic recovery after irradiation and PK of GT3 in NHP. GT3 could serve as an ideal radioprotective agent for use in humans, specifically for first responders and military personnel. Our pilot study with NHPs demonstrates that GT3 is a promising radioprotector. The views expressed do not necessarily represent the Armed Forces Radiobiology Research Institute, the Uniformed Services University of the Health Sciences, or the Department of Defense.
Abstract ID 0002
Cellular Therapy Without Cells: Extracellular Vesicles Promote Activation of Stem Cells After Irradiation
University Medical Center Hamburg-Eppendorf, Center for Stem Cell Transplantation, Dept.Cell and Gene Therapy, Martinistr. 52, 20246 Hamburg, Germany
Mesenchymal stromal cells from the bone marrow (MSC) have been shown to be effective in several cell therapeutic treatments. However, MSC accumulate in lungs after i.v. injection. How do MSC transfer their potential to organs with therapeutic need? We show that released extracellular vesicles (EV) might be playing an active role in this transfer. EV were isolated from MSC supernatant and characterized with flow cytometry, proteomics and next generation sequencing. Our data showed the transfer of RNAs, clustering into several protective gene groups. Besides, we repeatedly detected genomic DNA on vesicles. Using a plant-derived detector gene we showed horizontal DNA transfer via EV. Furthermore, we showed that EV were able to salvage stem/progenitor cells in vitro from radiation suppression. Three selected proteins from proteomics data were examined for stem cell protection after irradiation. EV derived from down-regulated producer MSC showed a substantial loss of protection in irradiated stem cells supporting their relevance for stem cell protection. Finally, we showed that EV after i.v. injection into lethally irradiated animals colocalize within 2-4 hours with hematopoietic stem cells in the bone marrow giving hint to direct protection of stem cells by EV. In conclusion, EV derived from bone marrow MSC were able to transfer several cargo compounds leading potentially to change of the genetic properties. Importantly, EV protect irradiated hematopoietic stem cells, stimulate their recovery and proliferation and rescue lethally irradiated animals long-term. Thus, EV might be an alternative for future cell therapeutic treatment particularly in radiation-based events.
Abstract ID 0004
Mechanisms of Hyperthermia Induced Radiatiosensitization for Treatment of Human Papillomavirus Positive Tumors
Arlene Oei, Caspar van Leeuwen, Lukas Stalpers, Hans Rodermond, Petra Kok, Hans Crezee and Nicolaas Franken
Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Experimental Molecular Medicine, Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, The Netherlands
HPV is associated with cervical cancer, the third most common cancer in women. In over 70% of cervical cancers, the high-risk HPV-types 16 and 18 are found. In these tumors, functionality of p53 is suppressed by the presence of protein E6. Hyperthermia is a clinical application of heat in which tumour temperatures are raised to 40-43°C and combined hyperthermia with radiation is very effective in the treatment of cervical cancer. Besides optimization of sequence and time between hyperthermia and radiotherapy for the treatment of cervical carcinoma, mechanisms of radiation sensitization are also investigated. Cervical carcinoma cells and experimental tumors were treated with hyperthermia (1 h 42°C), gamma-irradiation PARP1-inhibition and cisplatin. Patient cervical cancer biopsies were ex-vivo treated with hyperthermia only. Clonogenic survival assays and γH2AX stainings (DNA-DSB) were carried out. Expression levels of p53, E6 and DNA repair proteins were investigated. Combined treatments resulted in increased DNA-DSB as compared to radiation alone. Cisplatin and PARP1-inhibition significantly enhanced the combined hyperthermia/radiation treatment. Hyperthermia decreases BRCA2 levels and degrades E6 and thereby prevents the formation of the E6-p53 complex, unleashing p53-dependent apoptosis and G2-arrest. Adding PARP1-inhibitor or cisplatin significantly improves the effectiveness of hyperthermia treatment. Moreover, our findings provide new insights for patients who are suffering from HPV-positive cervical cancer, indicating that they would benefit from a treatment including hyperthermia.
Abstract ID 0006
Biological Modeling of the Radiation Dose Escalation Effect of Concurrent Hyperthermia
J. Crezee 1 , C.M. van Leeuwen 1 , A.E.Oei 1,2 , A. Bel 1 , L.J.A. Stalpers 1 , N.A.P. Franken 1,2 and H.P.Kok 1
1 Department of Radiation Oncology, Academic Medical Center, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands; 2 Laboratory for Experimental Oncology and Radiobiology, Academic Medical Center, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
Combined radiotherapy (RT) and hyperthermia (HT) treatments are successfully applied for different tumors. RT and HT treatments are normally planned separately, but should be performed taking the synergistic action between the two modalities into account. Purpose of this work is to evaluate the available experimental data on cytotoxocity of combined radiotherapy and hyperthermia treatments and to use these data to integrate hyperthermia and radiotherapy planning into a single planning thermoradiotherapy planning (TRTP) platform. Radiosensitisation can be modelled using the linear-quadratic (LQ) model to account for DNA repair inhibition by hyperthermia. We obtained temperature dependent alpha and beta parameters for the LQ model from literature and from experiments performed at LEXOR. Using these data, an integrated TRTP platform was created and then applied to evaluate the effective hyperthermic dose escalation for combined radiotherapy and hyperthermia treatments for prostate and cervical cancer. The TRTP system was used in a retrospective analysis to demonstrate that hyperthermic dose escalation is temperature dependent and equivalent to ~10 Gy for clinically realistic hyperthermia temperatures for prostate cancer and cervical cancer patients treated with radiotherapy and hyperthermia. Thermoradiotherapy planning is feasible and a necessity for an optimal clinical application of hyperthermia combined with radiotherapy in individual patients. This first version of TRTP is applicable for normally oxygenated tumour and normal tissue. The next step is modelling the effect of hyperthermia in hypoxic tumour cells including the physiological response to hyperthermia and the resulting reoxygenation.
Abstract ID 0007
Radiation Induced Dry Eye: Problem and Potential Remedies
Geeta K Vemuganti 1 Shubha Tiwari 2
1 School of Medical Sciences, Hyderabad; 2 LV Prasad Eye Institute, BITS Pilani
Advances in orbital radiotherapy have significantly increased therapeutic efficiency and reduced the side effects but a significant proportion of patients are still seen with ophthalmic complication like dry eye syndrome (DES). The treatment of DES involves temporary palliative therapies like ocular surface lubrication and rehydration. We aimed at establishing the human lacrimal gland cultures and evaluating for the presence of stem cells and secretory potential. Using human lacrimal gland tissues obtained from samples of therapeutic exenteration post-radiotherapy, we established a monolayer as well as 3D lacrispheres that show evidence of stem cells, secretory acinar cells, duct like formation and other cells like myoepithelial cells and duct like cells. The stem cells were identified as CD 117 positive that co-segregated with G0/G1 phase, ALDH high, label retaining cells and high clone forming ability. The most promising evidence of its secretory function was seen in the presence of tear substances like lysosymes, lactiferrin, and scIg A in the conditioned media of the lacrimal gland cultures. This novel development would pave way for development of a functionally competent 3D construct for potential clinical application in severe cases of radiation induced dry eye.
Abstract ID 0012
Radiation Dose Reduction due to Bladder Voiding Prior to Scanning, Measured from Patients Undergoing Positron Emission Tomography-Computed Tomography Imaging Using 18 F-Fludeoxyglucose
Khaled Soliman and Ahmed Alenezi
Medical Physics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia, P.O.Box 7897 Riyadh 11159
Accurate dose rate estimates are important for radiation protection specialists conducting risk assessments and performing dose reconstruction in cases of accidental exposures. The objective of this work was to experimentally measure the radiation dose rate reduction factor due to bladder voiding from patients undergoing PET/CT imaging studies using F-18 (FDG) by directly measuring the dose rate immediately before and after voiding, and compare the results with the current scientific literature. The radiation dose rate was measured using ionization chamber located at one meter distance from the interior patient body surface in standing position at the waste level. The same measurement is repeated after voiding and the dose reduction ratio was calculated. The bladder voiding effect had a dose rate reduction factor of about 12% between dose rates measured before and after voiding. We have measured dose rates at one meter from 50 patients and found an average dose rate per unit activity of 94.3 μSv/hr/GBq. Our results are in agreement with the current published data. The presented data can be applied in radiation protection optimization procedures, especially for the protection of the caregivers of patients undergoing FDG PET/CT imaging who are considered as a source of external radiation to others. The provided information will benefit medical physicists working in nuclear medicine and radiation safety policy makers.
Abstract ID 0013
Five Years' Experience of Occupational Radiation Dose Reduction in Positron Emission Tomography-Computed Tomography Imaging at Prince Sultan Military Medical City
Ahmed Aleneziand Khaled Soliman
Medical Physics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia, P.O.Box 7897 Riyadh 11159
The number of installed PET/CT scanners is increasing leading to an increased workload which could result in higher radiation dose received by nuclear medicine workers responsible for conducting the imaging studies in clinical environment. An effort should be made to further optimize the current dose reduction methods employed to achieve "as low as reasonably achievable" (ALARA) levels. The aim of this work is to provide an overview of the recent techniques used to reduce the occupational radiation doses in PET/CT practice. The worker radiation dose in PET/CT is higher than in conventional nuclear medicine practice. The higher radiation dose is mainly from the high energy annihilation photons. The highest radiation exposures to the involved staff occur during the dispensing, injection of the Radiopharmaceuticals and performing direct communications with the injected patients at close range. During the period of five years of PET/CT practice at Prince Sultan military medical city (PSMMC) in Saudi Arabia, we have implemented several methods for staff dose optimization. The methods included the following: (1) Training and experience of PET/CT staff, (2) use of time of flight (TOF) technology, (3) optimized design and layout of the department, (4) use of lead shields and automatic dispensing/injection systems. The results from implementing the dose optimization methods are reflected on the staff occupational dose records by a reduction of 55% over a period of 5 years.The presented data can be applied to optimize radiation protection practices during PET/CT imaging procedures.
Abstract ID 0014
Cellular Responses to Very Low Doses of Chronic High-Let Radiation in Mice In Vivo
S. S. Sorokina 1 , S. I. Zaichkina 1 , O. M. Rozanova 1 , S. P. Romanchenko 1 , H. N. Smirnova 1 , V. N. Peleshko 21
Institute of Theoretical and Experimental Biophysics, Pushchino, Russia 2 Institute of High Energy Physics, Protvino, Russia
It was shown previously that low-dose rate X- and γ-rays exposure of mice induces adaptive response (AR), does not affect the thymus weight after irradiation with a dose of 1.5 Gy, and decreases the tumor growth. The aim of the work was to investigate the cytogenetic effects of low-dose rate high-LET radiation on SHK mice. It was found that, in mice irradiated in the ranges of 0.1-30 ρGy (1 cGy/day) and 0.5-16 cGy (0.4 cGy/day), the numbers of polychromatic erythrocytes with micronuclei were similar and were two times higher compared with the level of spontaneous lesions. At the same time, no decrease of cytogenetic damage was detected after irradiation with a dose of 1.5 Gy. In a group of mice irradiated by the scheme of AR, the very low doses of high-LET radiation did not induce cytogenetic AR in hemopoietic organs (bone marrow cells; thymus) in contrast to chronic X-radiation. The results obtained indicate that the tumor mean size of mice depends on the dose value. It was also seen that very low-dose rate of high-LET radiation produce a more serious genetic damage to hemopoietic organs compared to low doses of chronic X- and γ-radiation.
Abstract ID 0016
Patient Radiation Dose Assessment of a Dental Cone Beam Computed Tomography Device using Different Types of Dosimetrs
Khaled Soliman , Mousa Bakkari, Abdullah Alrushoud, Salman Altimyat
Medical Physics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia, P.O.Box 7897 Riyadh 11159
This study compares different radiation dose metrics or indices and dosimeters used for evaluating patient doses from WhiteFox TM dental cone beam computed tomography (DCBCT) scanner. Another objective was to calculate conversion factors relating the measured entrance surface dose length product (ESDLP) to the scanner reported dose area product (DAP) values. This dosimetry study constitutes an important part of patient safety and radiation protection program in dental radiology. The ESDLP was measured using a 300 mm long computed tomography (CT) ionization chamber (IC). Gafchromic TM XR-QA2 films were used to measure the scanned length and area over the anthropomorphic head phantom; and therefore compute the DAP and compare the measurements with the reported DAP values available at the scanner console. Patient dose to the eye was measured using metal-oxide semiconductor field-effect transistor (MOSFET) solid-state radiation detectors. The measured ESDLP values for the most common dental CBCT examinations performed in our hospital was in the range of 30-70 [mGy.cm]. The DAP values ranged from 600-1200 [mGy.cm 2 ]. The patient eye doses ranged from 0.15-0.50 [mSv]. According to our study, Gafchromic films (XR-QA2) were found to be practical to measure radiation irradiated area over the surface of a phantom.The obtained results seem to agree with other published dosimetric studies covering other types of DCBCT scanners. The dosimetry results are important in order to document and audit radiation doses delivered to patients undergoing imaging studies using DCBCT. Patient dosimetry is a central part of the medical physics biannual quality assurance testing in DCBCT.
Abstract ID 0018
Various Perspectives of Using Radiation in Applied Entomology
R. K. Seth
Applied Entomology and Radiation Biology Unit, Department of Zoology, University of Delhi, Delhi-110007, India
Nuclear energy has manifold benefits due to its use in various disciplines of entomology ranging from basic to applied fields. Despite the laissez-faire use of broad-spectrum insecticides, especially in the tropical and subtropical zones of the world, the food losses due to insect pests both at pre- and post-harvest level are significant. New innovative, effective and environmentally sound pest control tactics are therefore needed. Presently, biological and para-biological control programmes are receiving major prominence due to insecticidal ill effects on health and environment, and development of insecticidal resistance in pests. Radiation mediated sterile insect technique (SIT) is an automatic birth control and it is a part of an arsenal of environmentally-friendly control tactics against some key insect pests. Inherited (F 1 ) Sterility technique (a modified SIT), has been potentially developed for managing the serious lepidopteran pests. Various other applications of ionizing radiation include disinfestation of agro-commodities for quarantine and phytosanitary purposes, augmentation of biological control and radiation hormesis for enhancing the efficacy of useful insects. Gamma radiation from isotopic sources (Cobalt-60 or Caesium 137) is most often used, but high-energy electrons and X-rays are the other practical options. Application of nuclear techniques for controlling a variety of noxious insects may lead to improvement in production of crop and animal produce, and protection from the dreadful communicable diseases. Various perspectives of application of radiation as a tool in different entomological arenas are highlighted.
Abstract ID 0019
Formulation for Simultaneous Action of Radiation and Environmental Factor
J.K. Kim 1,2 , J.-H. Kim 1 and V.G. Petin 3
1 Korea Atomic Energy Research Institute, Jeongeup 56212, Korea; 2 University of Science and Technology, Daejeon 34113, Korea; 3 Medical Radiological Research Center, Obninsk 249036, Russian Federation
Ionizing radiation can act on biological objects under the influence of other environmental factors. Many cases of the combined actions result in synergism. This study was done to elucidate regularities of the synergism. The hypothesis was that synergism might occur from an additional lethal or potentially lethal damage arisen from interaction of the two different types of sub-lesions induced by each agent. Those sub-lesions were regarded as ineffective when each agent acted separately. The additional damage responsible for the synergism was irreversible. Based on the regularities found, a numerical model was formulated. Our experimental results as well as data published by other researchers were used for model validation. Predictions by the model were in good agreement with experimental data. It was successful to apply the model to combined action of radiation with a physical or chemical factor. For a constant radiation dose rate, synergistic interaction of radiation with heat was realized only within a certain temperature range, independently of the target organisms analyzed. Any decrease in radiation dose resulted in an increase in the duration of combined action, i.e., thermo-radiation action to attain the same absorbed dose. The number of thermal sub-lesions would also be increased resulting in deviation from the condition in which the highest synergy should be observed. To sustain an optimal ratio of heat-induced damage to radiation-induced damage with any decrease in the dose rate, the exposure temperature should be decreased. In this regard, a long duration of interaction of ionizing radiation with environmental factors like high temperature is of importance from the standpoint of radiation protection, and of risk assessment as low intensities of harmful factors can, in principle, synergistically interact with each other.
Abstract ID 0020
Twenty Years Experience Of Carbon Ion Radiotehrapy at National Institute of Radiological Sciences-Heavy Ion Medical Accelerator in Chiba
Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
In 1994, CIRT (Carbon ion radiotherapy) was begun at the NIRS (National Institute of Radiological Sciences) using HIMAC (Heavy Ion Medical Accelerator in Chiba). As of March 2015, a total of 9,021 patients were treated with CIRT using HIMAC. The results have shown that CIRT has the ability to provide a sufficient dose to the tumor without unacceptable morbidity in the surrounding normal tissues. Tumors that appear to respond favorably to CIRT include locally advanced tumors and those with histologically non-squamous cell type of tumors. The efficacy of treatment regimen with small fractions in shorter treatment course has been also confirmed for almost all type of tumors in our experience. New techniques that deserve attention as the next generation system are the spot scanning beam delivery and the compact superconducting magnet mounted rotating gantry. A clinical research using the spot scanning was already in operation with the original fully automated patient positioning system since May 2011. Good performance of the spot scanning beam delivery system has been confirmed. Regarding the compact superconducting magnet rotating gantry, the gantry system was already installed and beam tests have been carried out at NIRS. The new gantry system will be expected to be in operation in early 2016.
Abstract ID 0021
7-Hydroxycoumarin Prevents Ultraviolet B induced photoaging through nuclear factor Kappa B Expression in Human Dermal Fibroblasts
R. Karthikeyan, G. Kanimozhi and N. Rajendra Prasad
Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalai Nagar, Tamilnadu, India.
Ultraviolet B (UVB) irradiation alters multiple molecular pathways in the skin, thereby inducing skin damage, including photoaging. Use of active dietary phytoconstituents will be beneficial in combating against the effects of UV rays. In the present study, we investigated the 7-hydroxycoumarin (7-OHC) against UVB induced photoaging. Human dermal fibroblasts (HDFa) were subjected to 18 mJ/cm 2 of UVB and phtoaging signaling were analyzed after 6 h incubation. 7-OHC dose was fixed by MTT assay. Reactive oxygen species (ROS) measured using DCFH-DA staining, loss of mitochondrial membrane potential by Rhodamine123 staining and DNA damage by comet assay. UVB induced inflammation were studied by western blot analysis. RT-PCR was employed to study photoaging and DNA repair enzyme expression. UV Spectrophotometry was used to determine sun protection factor of 7-OHC. Our results indicated that 7-OHC inhibited UVB induced ROS generation and loss of mitochondrial membrane potential in HDFa cells. Further, 7-OHC prevented the UVB induced DNA damage through upregulating DNA repair enzyme and restoring the antioxidant status. Results from western blot analysis revealed that the 7-OHC significantly decreased nuclear factor kappa B (NF-κB), TNF-α, IL-6 and COX-2 thereby prevents UVB induced inflammation in HDFa cells. Moreover, 7-OHC inhibited mRNA expression pattern of MMP-1 and MMP-9 in UVB irradiated HDFa cells. In addition, SPF of 7-OHC was found to be 9.8416 and this supports the photoprotective property of 7-OHC. 7-OHC offers protection against UVB induced inflammation and photoaging by modulating the NF-κB expression and also through its sunscreen property.
Abstract ID 0022
Preventive Effect of Linalool on Acute and Chronic Ultraviolet B Mediated Skin Damage and Photocarcinogenesis in Swiss Albino Mice
G. Srithar 1 and N. Rajendra Prasad 2
Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar-608 002, Tamilnadu, India.
Solar ultraviolet particularly, UVB radiation has been implicated as a primary cause of skin cancer, and basis for more than 90% of skin cancers by impairing cellular defence systems. Linalool, a monoterpene from essential oils, exhibits strong antioxidant potential and thereby may prevent UVB induced inflammation and phtocarcinogenesis. In the present study, we studied the anti-inflammatory mechanism of linalool on acute (7 days) UVB induced skin edema, skin thickness, hyperplasia, cyclooxygenase-2 (COX-2) and ornithine decarboxylase (ODC) activation in mouse skin. In addition, the effect of linalool on long term (210 days) UVB mediated photocarcinogenesis were studied by analyzing oxidative imbalance, inflammatory, immunosuppressive, angiogenic and apoptotic markers in mouse skin. Acute UVB (180 mJ/cm 2 ) irradiation induced hyperplasia, edema formation, lipid peroxidation, antioxidants depletion and increased the expression of cyclooxygenase-2 (COX-2) and ornithine decarboxylase (ODC). Pretreatment with linalool (topical and intraperitoneal) before each UVB exposure prevented acute UVB toxicity and downregulated the expression of COX-2 and ODC. In the chronic study, UVB exposed mice showed tumor incidence and activation of NF-κB, TNF-α, IL-6,COX-2, VEGF, TGF-ß1, Bax, Bcl-2 and mutated p53 in mouse skin. Pretreatment of linalool significantly prevented tumor incidence and the expressions of NF-κB, TNF-α, IL-6, COX-2, VEGF, TGF-ß, Bax, Bcl-2 and mutated p53. Furthermore, the histopathological observation confirmed that chronic UVB exposure induced dysplasia and squamous cell carcinoma and this has been prevented by linalool pretreatment. Therefore, linalool may be considered as a photochemopreventive agent against UVB induced skin carcinogenesis.
Abstract ID 0023
Caffeic Acid Inhibits UVB-induced Inflammation and Photocarcinogenesis Through Activation of Peroxisome Proliferator-activated Receptor-γ in Mouse Skin
B. Agilan and N. Rajendra Prasad*
Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Tamil Nadu, India-608002
Ultraviolet-B (UVB) radiation is a major etiological factor for development of skin carcinogenesis. In the present study, we designed to evaluate the preventive role of CA on short and long-term UVB exposed inflammation and photocarcinogenic events in mouse skin. Swiss albino mice were exposed to 180 mJ/cm 2 of UVB once daily for 10 consecutive days and weekly thrice for 30 weeks for acute and chronic study, respectively. Alterations in skin histology, edema formation, antioxidants status, inflammatory markers expression, transcription factors activation and tumor growth and development were analyzed at the end of the experimental period. UVB exposure for 10 consecutive days showed edema formation, increased lipid peroxidation, decreased antioxidant status with activation of inflammatory molecules such as TNF-α, IL-6, COX-2 and NF-κB. Whereas, CA (15 mg/kg.b.wt.) administration before each UVB exposure decreased lipid peroxidation, inflammatory markers expression and enhanced antioxidant status probably through the activation of peroxisome proliferator-activated receptors (PPARγ) in the mice skin. Furthermore, UVB exposure for 30 weeks caused Squamous cell carcinoma and upregulation of iNOS, VEGF, TGF-ß and down-regulation of p53 and tumor incidence in the mice skin. CA treatment before each UVB exposure downregulates iNOS, VEGF, TGF-ß, upregulates p53 and reduces tumors multiplicity in the mice skin. Thus, caffeic acid offers protection against UVB-induced photocarcinogenesis probably through activation of anti-inflammatory transcription factor PPARγ in the mouse skin.
Abstract ID 0025
Umbelliferone Modulates Gamma-Radiation Induced Reactive Oxygen Species Generation and Subsequent Oxidative Damage in Human Blood Lymphocytes
G. Kanimozhi , N. Rajendra Prasad and K.V. Pugalendi
Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalai Nagar, Tamilnadu, India.
Umbelliferone, also known as 7-hydroxycoumarin, is a widespread natural product of the coumarin family. The purpose of this study was to investigate the protective effect of umbelliferone, against radiation-induced oxidative damage and chromosomal aberrations in cultured human blood lymphocytes. Freshly isolated human blood lymphocytes were treated with 124 μM of umbelliferone followed by 3 Gy irradiation. After 24 h incubation, the cellular oxidative damages, cytogenetic damages and apoptotic events were analyzed. Umbelliferone pretreatment (124 μM) 30 min before 3 Gy gamma irradiation inhibited gamma radiation-induced reactive oxygen species generation, decreased mitochondrial membrane potential and significantly decreased % of apoptotic cells in lymphocytes. Further, there was an increased DNA damage (comet assay), cytokinesis-blocked micronuclei frequency, chromosomal aberration attributes, lipid peroxidation with decreased antioxidant enzymatic i.e., superoxide dismutase, catalase and, glutathione peroxidase activities in 3 Gy irradiated lymphocytes. Conversely, umbelliferone (124 μM) treatment before irradiation decreased %DNA damage, micronuclei frequencies, chromosomal aberration attributes and lipid peroxidative markers with improved antioxidant enzyme activities in irradiated lymphocytes. Further, umbelliferone pretreatment modulates radiation-induced apoptotic signaling in human blood lymphocytes.Thus, umbelliferone exhibits radioprotective effect in human lymphocytes probably through inhibiting reactive oxygen species generation and its subsequent radiation toxicity.
Abstract ID 0026
Natural phenolics for the prevention of ultraviolet-B radiation induced
cellular and molecular events
N. Rajendra Prasad
Department of Biochemistry and Biotechnology, Annamalai University, Annamalai Nagar 608 002
Ultraviolet radiation (UV) is a very prominent environmental toxic agent. Particularly, UVB (280 - 320 nm) wavelengths penetrate the epidermis and are nearly fully absorbed in the upper dermis, whereas UVA (320 - 400 nm) penetrates to the deeper dermis. UVA is a relatively weak carcinogen than UVB as a tumor initiating agent. UVB-irradiation acts as both tumor initiator and tumor promoter. Cellular changes, including activation of transcription factors and protein kinases are accelerated during acute and chronic UVB-exposure contributes photocarcinogenesis. Epidemiological studies show that consuming vegetables and fruits are protected from UVB induced carcinogenesis. Natural nutraceuticals and dietary phenolic acids targets UVB-mediated cellular and molecular events and prevents cellular milieu from UVB mediated adverse effects. The intraperitoneal and topical administration of phenolic acids significantly reduced the UVB-induced tumor incidence and prevented the UVB-induced hyperplasia, squamous cell carcinoma (SCC) and dysplastic feature in the mice skin. Further, phenolic acids reverted chronic UVB-induced oxidative damage accompanied with modulation of inflammatory and photoaging. Furthermore, these phytochemicals potentially interact with PPARγ, an anti-inflammatory transcription factor, and downregulates iNOS, VEGF, TGF-ß thereby reduces tumors multiplicity in the mice skin. Chronic UVB irradiation induces the expression of JAK1 eventually activates the STAT3 leads to the transcription of proliferative and antiapoptotic markers such as PCNA, Cyclin-D1, Bcl2 and Bcl-xl, respectively. Caffeic acid rather than ferulic acid inhibits JAK-STAT3 signaling thereby induces apoptotic cell death by upregulating Bax, Cytochrome-C, Caspase-9 and Caspase-3 expression in mice skin. In this talk, the current progress in the study of UVB-mediated signaling that can be exploited as targets for phytochemicals for photoprotection and photochemoprevention will be discussed.
Abstract ID 0027
Alternative end Joining is A Key Mediator of Ionizing Radiation Induced Translocations in Rodent and Human Cells - Serving as Universal Backup end Joining
Aashish Soni 1 , Maria Siemann 1 , Tamara Murmann 1 , Gabriel E. Pantelias 2 and George Iliakis 1
1 Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen, Germany 2 Institute of Nuclear Technology and Radiation Protection, National Centre for Scientific Research ''Demokritos,''Aghia Paraskevi Attikis, Athens, Greece
Ionizing radiation (IR) induces double strand breaks (DSBs) in cellular DNA, which if not repaired correctly can cause chromosome translocations (CTs) leading to cell death or cancer. Incorrect joining of DNA ends leading to CTs can be catalyzed either by DNA-PKcs-dependent, classical non-homologous end-joining (c-NHEJ), or by an alternative end-joining (alt-EJ) process, functioning as backup to abrogated c-NHEJ or homologous recombination repair, operating with slower kinetics, and generating larger alterations at the junction including CTs. As a result of its fundamental operating properties, alt-EJ is considered crucial to the formation of CTs. A recent study using designer nucleases to induce DSBs and PCR to detect CTs shows a robust, dominant induction of CTs by c-NHEJ in human cells. In c-NHEJ mutants, significantly fewer CTs are observed, which only then show microhomologies as typical signatures of alt-EJ at the generated junctions. On the basis of these observations it is concluded that in human cells, CTs formation is mainly catalyzed by c-NHEJ, in stark contrast to results with rodent cells, where alt-EJ plays a dominant role. Here, we revisit the issue in human cells using stochastically induced DSBs and classical cytogenetics for the detection of CTs. We report that similar to rodent cells, CTs in human cells exposed to IR are largely mediated by Parp1 and Ligase3 mediated alt-EJ and that c-NHEJ strongly suppresses CTs particularly for cells irradiated in G2-phase. Interestingly, the inhibition of Lig1, Lig3 and Lig4 together resulted in almost complete inhibition of translocations. The results point to important cell cycle dependencies of the mechanisms involved in CTs formation that will require further investigations.
Acknowledgements: DFG Graduate Training Program 1431, BMBF and BMWi.
Abstract ID 0028
A Herbal Composition (Hemohim) as a Complementary Agent for Cancer Radiotherapy and Chemotherapy
Sung-Kee Jo 1, Hae-Ran Park 1 , Uhee Jung 1 , Soo Young Choi 2 , Sung-Ho Kim 3
1 Radiation Research Division for Biotechnology, Korea Atomic Energy Research Institute (KAERI), Jeongeup-si, Jeonbuk-do 580-185, Republic of Korea; 2 Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea; 3 College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea
HemoHIM, a herbal composition of three edible herbs (Angelica Radix, Cnidium Rhizoma and Paeonia Radix), was developed to protect the immune, hematopoietic, and intestinal tissues against radiation. In this study, we examined the possibility of HemoHIM to enhance anticancer effect with ionizing radiation (IR) and chemotherapeutic agents (cisplatin) and to reduce the side effects of chemotherapeutic agents in tumor-bearing mice. In tumor-bearing mice, IR (5 Gy) or cisplatin treatment reduced the weight of the solid tumors, and HemoHIM supplementation significantly enhanced the decrease of the tumor weight. In tumor-bearing mice treated by IR or cisplatin, HemoHIM administration increased the activity of NK cells and Tc cells, although the proportion of these cells in spleen was not different. In addition, HemoHIM administration increased the IL-2 and TNF-a secretion from lymphocytes stimulated with ConA, which seemed to contribute to the enhanced efficacy of HemoHIM in tumor-bearing mice treated with IR or cisplatin. Furthermore, HemoHIM significantly reduced the damage of liver and kidney by cisplatin. In a preliminary clinical study, 85 patients, diagnosed with breast or uterine cervix cancer, were administered with HemoHIM (6g/day) for 12 weeks during radiation and /or chemotherapy. Age-matched 209 patients were monitored as control group. In the HemoHIM group, fewer cases of severe leucopenia (<3,000 leukocytes/mm 3 ) were shown compared with the control group, and it was more evident in the breast cancer patients. In conclusion, HemoHIM may be a beneficial supplement during radiotherapy and chemotherapy for enhancing the anti-tumor efficacy and reducing the side effects.
Abstract ID 0030
Enhancing the Response of Cervical Cancers Treated with Radio(chemo)therapy
R.P. Hill 1 , 3, 4 N. Chaudary 1 , M. Milosevic 2,4
1 Ontario Cancer Institute, Toronto, Canada; 2 Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; 3 Department of Medical Biophysics, University of Toronto, Toronto, Canada; 4 Department of Radiation Oncology, University of Toronto, Toronto, Canada
There is an important need to improve the effectiveness of frontline radio-chemotherapy (RTCT) for cervical cancer since approximately 30% of patients recur following treatment and further treatment options are limited. These tumors often contain significant fractions of hypoxic cells that can reduce tumour response and enhance metastases, one mechanism of which may be CXCR4 upregulation. The objective of this study was to explore combined treatment with Plerixafor (a CXCL12/CXCR4 inhibitor) and standard RTCT on primary tumor response and the development of metastases, using orthotopic primary xenografts (OCICx13 and OCICx20) derived directly from patients with cervical cancer. To simulate clinical treatment, image-guided radiotherapy (30 Gy in 15 daily fractions) and concurrent weekly cisplatin (4 mg/kg) were administered, with or without Plerixafor (5 mg/kg/day). The primary endpoints were tumor growth delay and the frequency of para-aortic lymph node metastases. Effects of Plerixafor treatment on acute gut toxicity was assessed using the crypt cell assay. Late toxicity is being examined by histology. The combination of Plerixafor with RTCT produced enhanced tumor growth delay, reduced metastases and improved survival compared to standard RTCT alone in the patient-derived xenograft models. There was a reduction in chemokine signaling (CXCL12/CXCR4) with combination treatment compared to RTCT alone. There was no effect of Plerixafor on acute GI toxicity. Analysis of late normal tissue toxicity is currently underway. This preclinical study demonstrates that the addition of Plerixafor to standard RTCT for cervical cancer improves local tumor response and reduces metastases with no apparent increase in early toxicity.
Abstract ID 0031
Microrna Screening as a Functional Genomics Tool for Prostate Cancer: Road from Discovery to Therapy
Binod Kumar 1* , Koji Hatano 1 , Tarana A. Kudroli 1 , Yonggang Zhang 2 , Wasim H. Chowdhury 3 , Theodore L.DeWeese 1, 2, 4 , Shawn E. Lupold 1, 2, 4
1 The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; 2 The Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; 3 The Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; 4 The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
The discovery of RNA interference and microRNA (miRNA) gene regulation in human cells has dramatically changed the way we view and study cancer. However, there are still many unanswered questions and technical difficulties associated with miRNA research. One major difficulty is in identifying which specific miRNA regulates a specific gene or pathway. This is complicated by the fact that miRNAs can affect different genes and different pathways in cell specific manner. To answer these questions, we performed series of functional screen in prostate cancer (PCa) cells to identify; a) miRNAs that regulate the androgen receptor (AR) signaling, a key molecule associated with the progression as well as resistant to the PCa, and b) miRNAs that are associated with DNA repair pathways to use miRNA as a radiation sensitizer. Using high throughput screening assays, we have identified a series of miRNAs that affect AR signaling in PCa cells. Bioinformatic analysis and clinical samples validate these findings. In an independent study, a functional screen was performed to examine the effects of individual miRNAs on IR sensitivity. A large percentage of miRNA were found to increase cellular sensitivity to IR, while a smaller percentage were protective. Two of the most potent IR sensitizing miRNAs, miR-890 and miR-744-3p, significantly delayed IR induced DNA damage repair, while intratumoral delivery of miR-890 mimetics prior to IR therapy significantly enhanced IR therapeutic efficacy. In conclusion, series of functional screening in PCa implies the regulatory role of miRNAs for specific gene (AR) or pathways (DNA repair).
Abstract ID 0032
Structural Characterization and Evaluation of Antioxidant and Anticancer Activity of Radiation Depolymerized Oat (Avena sativa) b-Glucan
P. R. Hussain * , S. A. Rather and P. P. Suradkar
Astrophysical Sciences Division, Nuclear Research Laboratory, Bhabha Atomic Research Centre, Zakura, Srinagar - 190006, Kashmir, India
Oats (Avena sativa) beta- D -glucan after extraction and partial purification was subjected to gamma irradiation in the dose range of 3 - 15 kGy and evaluated for structural changes and enhancement in antioxidant and anticancer activities using different assays. The results of the study revealed dose dependent decrease in molecular weight with concomitant increase in solubility and water absorption capacity. Comparison of the FTIR spectra of control and gamma irradiated oat ß- D -glucan revealed that after irradiation, the important functional groups were still present and the main polysaccharide chain structure remained intact. However, the side chain carbonyl and C-H groups had shifted slightly to lower wave numbers at doses above 9 kGy. XRD analysis revealed no significant difference in diffraction patterns of control and irradiated beta-glucan samples, except a decrease in crystallinity after exposure to irradiation. Results of antioxidant assays indicated significant (p ≤ 0.05) decrease in EC 50 values for all the assays with increase in irradiation dose, thereby enhancing the antioxidant activity of oat ß-glucan. Comparisons of the EC 50 values indicated significant (p ≤ 0.05) enhancement in ferric reducing ability power and DPPH radical scavenging of oat ß-glucan due to irradiation treatment. Cell line studies demonstrated significant potential of radiation depolymerized oat ß-glucan as natural anticancer agent. Thus it could be concluded that low molecular weight oat ß-glucan produced by gamma irradiation has potential applications both in food and pharmaceutical industry.
Abstract ID 0033
Assessment of Entrance Skin Doses for Patients Undergoing Diagnostic X-Ray Examinations in Some Major Hospitals of Uttarakhand, India
S. C. Uniyal 1 , V. Prasad 1 , V. Chaturvedi 1 , S. D. Sharma 2 , S. Raghuvanshi 1
1 Department of Radiology, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Jolly Grant, Dehradun, India- 248016; 2 Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Anushaktinagar, Mumbai, India-400085
Over the last 100 years, diagnostic X-ray has found increasing applications in medicine and is presently accepted as an important tool for medical diagnosis. However, the radiation dose resulting from medical diagnostic X-ray examinations is the largest man made source of population exposure to ionizing radiation. The International Commission on Radiological Protection (ICRP) has recommended that all medical exposures should be justified and kept as low as reasonably achievable. The present study was carried out to estimate the trend of dose received by patients during 11 routinely performed diagnostic X-ray examinations in 10 major hospitals of Uttarakhand, India. Entrance skin dose (ESD) was calculated based on the X-ray beam output, the exposure parameters used for the actual examination and the standard value of backscatter factor. Descriptive statistics were generated from the data by using Microsoft Excel 2010. The third quartile values of ESDs obtained in this study for different X-ray projections of chest anterior-posterior (AP), chest posterior-anterior (PA), cervical spine, thoracic spine, lumber spine AP, lumber spine lateral, abdomen, KUB, pelvis, skull and knee joint were 0.79, 0.28, 1.20, 2.80, 4.26, 9.82, 2.68, 3.21, 2.69, 2.21 and 0.55 mGy respectively. The ratio of maximum to minimum ESD values ranges from 5.2 for thoracic spine to 19.76 for chest AP X-ray examinations. In general, the obtained ESD values were found to be either lower than or in agreement with the reported national/international values.
Acknowledgement: This work has been supported by a grant from Board of Research in Nuclear Sciences.
Abstract ID 0034
Grape (Vitis Vinifera) Extracts Protect against Radiation-Induced Oxidative Stress in Human Erythrocyte (Red Blood Cell)
Indrani Singha 1 , S. Gautam 2 and Subir Kumar Das 1
1 Department of Biochemistry, College of Medicine and JNM Hospital, WBUHS, Kalyani, Nadia 741235, West Bengal; 2 Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085
Ionizing radiation (IR) causes oxidative stress through the overwhelming generation of reactive oxygen species (ROS) in the living cells leading further to the oxidative damage to biomolecules. Grapes (Vitis vinifera) contain several bioactive phytochemicals and are the richest source of antioxidant. In this study, we investigated and compared in vitro antioxidant activity and DNA damage protective property of the grape extracts of four different cultivars, including the Thompson seedless, Flame seedless, Kishmish chorni and Red globe. The activities of ascorbic acid oxidase and catalase significantly (p<0.01) differed among extracts within the same cultivar, while that of peroxidase and polyphenol oxidase did not differ significantly among extracts of any cultivar. In vitro antioxidant activities were assessed by ferric-reducing antioxidant power (FRAP) assay and ABTS. The superoxide radical-scavenging activity was higher in the seed as compared to the skin or pulp of the same cultivar. Pretreatment with grape extracts attenuates oxidative stress induced by 4 Gy g-radiation in human erythrocytes in vitro. These results suggest that grape extract serve as a potential source of natural antioxidants against the IR-induced oxidative stress and also inhibit apoptosis. Furthermore, the protective action of grape depends on the source of extract (seed, skin or pulp) and type of the cultivars.
Acknowledgements: Financial assistance received from DAE-BRNS is gratefully acknowledged
Abstract ID 0035
Prediction of Radiotherapy Induced Normal Tissue Adverse Reactions: The Role of Double-Strand Break Repair
B. S. Satish Rao , K. D. Mumbrekar 1 , H.V. Goutham 1 , J. F. Donald 2 , M.B. Vadhiraja M 3 and K. Satyamoorthy 4
1 Department of Radiation Biology and Toxicology, 4 Department of Biotechnology, School of Life Sciences, Manipal University, Manipal, India. 2 Department of Radiotherapy and Oncology, Shiridi SaiBaba Cancer Hospital and Research Centre, Manipal University, Manipal, India. 3 Department of Radiotherapy and Oncology, Manipal Hospital, Bangalore, India.
With the improved cure rates, survivorship issues related to quality of life of cancer patients become increasingly important. DNA double strand break repair may influence the development of radiotherapy (RT) induced adverse reactions and therefore insight on this may have direct clinical implications. Prior understanding on the repair potential of an individual may enable a clinician for personalized care and therefore, may contribute to increased therapeutic outcome.Therefore, predicting the risk of developing acute reactions before the initiation of RT using cellular or molecular based assaysmay serve as a potential biomarker. We aimed at evaluating the predictive potential ofDSB repair kinetics(using γH2AX foci assay) in lymphocytes and analysed the genetic variants in theselected radioresponsive candidate genes like XRCC3, LIG4, NBN, CD44, RAD9A, LIG3, SH3GL1, BAXS, XRCC1, MAD2L2on the individual susceptibility to RT induced acute skin reactions among the head and neck cancer (HNC), and breast cancer (BC) patients. All the 183 HNC and 132 BC patients were treated by a 3-dimensional conformal RT technique. The severity of skin damage was scored according to the RTOG criteria for acute skin adverse reactions and the toxicity scores were dichotomized as non-over-responders (NOR) and over-responders (OR)for analysis.DSB repair capacity measure by γH2AX foci assay could differentiate between the OR from NORs both in BC and HNC patients. Further, the genetic variants in NBN, rs1805794 (p = 0.023) and CD44, rs8193 (p = 0.027) were associated with acute skin reactions in HNC and BC respectively. Haplotype analysis of NBN (rs1805787, rs1805794) gene demonstrated G-C haplotypes to be associated with development of oral mucositis in HNC.Based on these results it may be concluded thatprior understanding on the DSB repair potential / defects in this pathway may have its potential as a predictive biomarker.
Acknowledgements: The financial support from DBT (BT/01/COE/06/02/07) and Manipal University for providing the research facilities are gratefully acknowledged.
Abstract ID 0037
Monte Carlo Calculation of Microdosimetric Quantities for Photons of Different Energies
Arghya Chattaraj , T. Palani Selvam, and D. Datta
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai
Microdosimetry deals with the nature of the energy transfers which occur in cellular or subcellular structures. Tissue Equivalent Proportional Counter (TEPC) is the most widely used detector for experimental microdosimetry. It helps in characterizing the radiation quality in radiation protection and radiation therapy environments. In the present study, microdosimetric quantities such as frequency distributions of lineal energy f(y), specific energy f(z) and their corresponding frequency mean lineal energies (y F and z F ) and dose mean lineal energies (y D and z D ) are calculated for photon energies in the range 20 keV - 1.25 MeV. The above quantities are also calculated for radiotherapy photon beam from the Bhabhatron telecobalt machine. The calculations are based on Monte Carlo techniques using the FLUKA code. In the Monte Carlo calculations, a spherical TEPC has been simulated. Density of tissue equivalent gas (propane) inside the TEPC is adjusted to simulate cell diameters of 2 micron, 5 micron and 10 micron. In the calculations, energy thresholds for both electron and photon are set to 1 keV. For scoring f(y), DETECT card is used in the calculations. For low energy incident photons, electron transport in the TEPC is performed with single scattering mode. For 20 keV photons, the values of y F and y D for 2 micron simulated site size are 2.43 and 3.87 keV/micron, respectively. For the Bhabhatron machine, the corresponding values at 5 cm depth in water phantom are 0.45 and 1.70 keV/micron. Presence of collimator, jaws and water phantom have a marginal influence on the above values.
Abstract ID 0038
Effect of Gamma Irradiation on Pollen Viability, Pollen Germination and Pollen Tube Length in Bread Wheat (Triticum aestivum)
Jayaprakash P, Sheeba D, Vikas V.K, Sivasamy M and Annapoorani S
ICAR- Indian Agricultural Research Institute, Regional Station; Wellington -643231, The Nilgiris, Tamil Nadu, India
The irradiation effects of different doses (200, 250, 275, 300, 325 and 350 Gy) of gamma rays on wheat seeds were investigated on pollen parameters such as pollen viability, pollen germination and pollen tube length. The seeds treated at a dose of 350 Gy did not germinate. The pollen was germinated in four pollen germination media (PGM) at 17°C. The pollen of control showed > 90 per cent pollen germination in a medium (M19) consists of 19% maltose + 13 % PEG + 60 mgl -1 boric acid + 50 mgl -1 calcium nitrate+ 100 mgl -1 KMNO 3 + 200 mgl -1 MgSO 4 . However, pollen tube bursting occurred upto 85 per cent. The medium (M19) was added with EACA and/ or peptone to control pollen burst. It was observed that the pollen germination and pollen tube length decreased with increasing concentration and all treatments recorded highest value in medium M19+ 500 mgl -1 EACA + 100 mgl -1 peptone. The control recorded pollen germination (PG) of 95.47% with 403µm mean pollen tube length (PTL) followed by 200 Gy treatment of 30.77% PG with 230 µm PTL, 250 Gy treatment of 27.23% PG with 190 µm, 275 Gy dose of 15.56 PG with 216 µm PTL and the least score with 300 Gy treatment of 6.52% with 156 µm of mean pollen tube length was recorded. The pollen from the plants irradiated to 325 Gy did not germinate. The irradiation treatment significantly affected all the pollen traits studied. The pollen viability of all treatments was also tested with Alexander staining and the results of in vitro pollen germination and staining were comparable.
Abstract ID 0039
Bioinformatics Database on Radiosensitizers and Radioprotectors
Amruta Joshi and Prabhakar Dongre
Department of Biophysics, University of Mumbai, Mumbai, India, 400098
Radiotherapy is considered as one of the most important therapeutic modality for the treatment of cancers. With the use of radiosensitizing/radioprotective agents in radiation therapy, the cure rate has been increased either by radioprotective or radiosensitizing mechanisms. Therefore, radiosensitizers and radioprotectors are being studied on various biological models in vitro/ vivo across the globe to improve the therapeutic efficiencies. From literature survey, it is found that there are number of radiosensitizers and radioprotectors (approximately 350) which have been studied and some are clinically tested. Here, we have taken up a task of designing a database on radiosensitizers and radioprotectors in such a way that one can retrieve almost all sort of information on these agents with just one single click. The information is basically categorized into eight main sections of these agents viz. General features, Therapeutic dose, Biological targets, Radiobiological properties, Pharmacological study, Clinical study, Toxicity and Test system study. The information is collected through original research articles, reviews, books, correspondences, short communications etc. SQL (Sequence Query Language) is used as back end user language, whereas PHP is employed as front end user language while creating this database. Software used to build up this database is MySQL. Design of database allows user to navigate through various sections with minimal efforts and also provides privileges like "advanced search" which assures specificity and selectivity of the search.
Abstract ID 0040
Critical Role of Hypoxia-Driven Adenosine Accumulation in the Anti-Tumor Immune Response Elicited by Radiotherapy
Department of Radiooncology and Radiotherapy, Tumor Pathophysiology Section, University Medical Center, Langenbeckstrasse 1, Mainz 55126, Germany
The development of tumor hypoxia is accompanied, apart from modified gene expression and genetic instability, with a substantial accumulation of the nucleoside adenosine (ADO) in the range of 50-100 microM (normal tissues: 10-100 nanoM). ADO accumulation is preferentially caused by an ATP release from cancer cells into the extracellular space upon hypoxic stress. After transport out of cancer cells, ATP is converted into ADO by hypoxia- sensitive, membrane- bound ectoenzymes CD39 and CD73. ADO-actions (adenosinergic effects) are mediated upon binding to surface receptors, mainly A2A-receptors on tumor and immune cells. Receptor activation leads to a broad spectrum of strong immune-suppressive properties through modulation of the innate and adaptive immune system, thus facilitating tumor escape from immune control. Mechanisms include (a) impaired activity of CD4 + T and CD8 + T, NK cells and dendritic cells (DCs), decreased production of immune- stimulatory lymphokines, and (b) activation of Treg cells, expansion of myeloid- derived suppressor cells (MDSCs), promotion of pro-tumor M2-macrophages and increased activity of major immune- suppressive cytokines. In addition, ADO can directly stimulate tumor cell proliferation and angiogenesis. In contrast to ADO, standard radiotherapy (RT) and fever- range hyperthermia (HT) can stimulate anti- tumor immune responses. It is concluded, that ADO- mechanisms described can thwart anti- tumor immune responses elicited by RT and HT. Therapeutic strategies alleviating tumor- promoting activities of ADO include respiratory hyperoxia (or other measures to overcome tumor hypoxia), inhibition of CD39/CD73 ectoenzymes or blockade of hypoxia-dependent A2A-receptors (optionally in combination with immune checkpoint blockade), and inhibition of ATP-channels or hypoxia-sensitive ADO-transporters.
Abstract ID 0041
Gamma Rays - Its Role in the Improvement of Emmer Wheat (Triticum Dicoccum), A Functional Food
V.K.Vikas 1 , M. Sivasamy 1 , P. Jayaprakash 1 , Jagdish Kumar 2 , S.G. Bhagwat 3 and B.K. Das 3
1 ICAR-Indian Agricultural Research Institute (I.A.R.I.), Regional Station, Wellington 643 231; 2 ICAR-Indian Agricultural Research Institute (I.A.R.I.), Regional Station, Shimla 171 004; 3 Mutation Breeding Section, Bhabha Atomic Research Centre (BARC), Mumbai 400 085
Emmer wheat (Triticum dicoccum), commonly known as Khapli is gaining importance as functional/therapeutic food because of the low glycemic index, slow digestability, high satiety value coupled with resistant starch, high protein and fibre. These quality attributes are considered vital for the dietary management of diabetes and cardiovascular risks. Traditional varieties of emmer are tall, susceptible to lodging and low yielding, however modern semi dwarf cultivars are high yielding with low quality. Most of the semi dwarf dicoccum cultivars derived their dwarfing genes from Triticum durum and it has strong linkage drag in altering the quality traits. This necessitates the need to search for new sources to create variability among the dicoccum gene pool wherein mutation provides a helping hand. Seeds of traditional variety, NP201 were subjected to 100, 200, 300 and 400 Gy of gamma rays. In the M 2 population of 200 Gy treatment, a reduced height mutant with vigorous growth and high tillering was observed. This semi dwarf line with high yield and stable performance was selected at M5 generation. Stable mutant matured in 105 days with an average plant height of 80 cm and a mean yield of 45 q/ha, compared to 120 days to maturity, 120 cm plant height and mean yield of 30q/ha of parent (NP201). Moreover, mutant had comparable level of protein (16.8%), sedimentation value (29.0 ml) and Beta carotene (3.39 ppm) as that of parent (NP201). This mutant was released as variety HW1098 for cultivation to the farmers of dicoccum cultivating areas of Maharashtra, Gujarat, Karnataka and Tamilnadu by the Central Varietal Release Committee.
Abstract ID 0042
Electron Beam Irradiation of Ready to Eat Indian Cuisines for Longer Shelf Life
Shimmy Shankar M 1 ,Manoj Mulmule 2 , Vaishali Bambole 3 , Sahayog N Jamdar 4 , K. P Rawat 5
1, 2, 3 Department of Physics, Thilak Bhavan, Vidyanagiri, Kalina Campus, Santacruz(E), Mumbai-98, 4 Food and Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai-85, 5 Board of Radiation and Isotope Technology, BRIT/BARC Vashi complex, sector 20,Navi Mumbai-400703
E-mail: shimmy.shankar @gmail.com
Idli, a nutritious food item consumed in India is a steam cooked fermented food famous for its spongy texture and unique fermented taste. Preparation of idli is a time consuming process; it involves soaking, grinding and fermentation of the batter prepared from black gram dal and rice. Although instant idli pre-mixes in the form of powder or batter are available in the market, they do not have the distinctive taste and aroma, hence ready to eat form of this food is in demand. In present work, an attempt is made to prepare ready-to-eat idli with an extended shelf life of up to one month at ambient temperature using hurdle technology. The hurdle technology comprised of Accelerated Electron Beam irradiation at dosages (2.5 kGy, 5 kGy, and 7.5 kGy), vacuum sealing and heating. The treated idli samples were assayed at storage period of 24 hours, two weeks and one month for microbiological safety and sensory acceptability. The control idli which gets spoiled within 3 days with microbial count 10 7 CFU/g at room temperature storage was found to remain shelf stable when treated with radiation dosage of 5 kGy and 7.5 kGy for one month. The radiation dosage of 2.5 kGy alone was not sufficient to preserve idlis for more than two weeks but when used in combination with heating, they remained safe for one month with acceptable quality. Hence, hurdle technology can be used to enhance the shelf life of idlis up to one month with better retention of organoleptic properties.
Abstract ID 0043
Shelf Life Extension of Fresh Fish, Scomberomorus guttatus (Surmai) by Electron Beam Treatment
K. P. Rawat , S. A. Khader and K. S. S. Sarma
Electron Beam Processing Section, RTDD, BARC, BRIT-BARC Complex, Sector-20, Vashi, Navi Mumbai
The role of ionizing radiation in controlling the spoilage micoflora of various food products is well established. Most of the work done in India in the field of food preservation is done by using Cobalt-60 gamma ray technology. We have explored the efficacy of electron beam in increasing the shelf life of sea fish, Scomberomorus guttatus (Popularly known as Surmai). The fresh fish was procured from local market, cut in 30 mm slices and then treated with 3 kGy of EB dose and subsequently stored at 0-3°C. The total viable counts in control samples increased rapidly and the sample got spoiled in 7 days of storage at 0-3 O C, whereas no microbial growth was noticed in EB treated samples till 28 days of storage. The EB treatment completely eliminated the faecal coliforms, S. aureus and Salmonella from EB treated samples. This proves the efficiency of EB in eliminating the spoilage micro-organisms and extending its shelf life. The lipid peroxidation increased during storage period for control as well as EB treated samples. The result of our experiment showed that the shelf life of EB treated surmai fish can be extended from 7 days to 28 days when stored at 0-3°C. Traditionally, fish produce in our country is stored at ice temperature which has very short shelf life. The EB treatment of fresh fish will increase the shelf life upto four weeks and thus bring fishermen more economic benefits.
Abstract ID 0044
Enhanced Biodegradation of Textile Industry Effluent by Electron Beam Pre-treatment
K. P. Rawat , S. A. Khader and K. S. S. Sarma
Electron Beam Processing Section, RTDD, BARC, BRIT-BARC Complex, Sector-20, Vashi, Navi Mumbai
The effectiveness of ionizing radiation in reducing microbial load from waste water is well documented. It is also reported to reduce some of the physico-chemical parameters of wastewater. Generally, textile industry effluent is very high in BOD/COD content. The conventional waste water treatment process (mostly biological in nature) is not very effective in reducing the BOD/COD concentrations to permissible level. The ionizing radiation is also found to reduce these parameters upto a certain extent. We have investigated the effect of electron bean radiation in reducing the BOD/COD concentration of textile industry effluent, with and without biological process. The textile industry effluent was brought from textile industry combined treatment plant, Dombivali. The effluent was subjected to various doses of EB (1 to 50 kGy). Maximum reduction of 13% for COD and 50% of BOD was noticed when effluent was treated with EB dose of 50 kGy. In the second phase of experiments, we treated the effluent with 10 kGy of EB dose and then subjected it for biological degradation. The EB pre-treated effluent showed 43% reduction in COD value and the BOD value was reduced by 79%. The EB pre-treatment has enhanced the efficiency of biological process. This could be due to conversion of non biodegradable fraction into biodegradable fraction by EB treatment. The EB pre-treatment for textile industry effluent before biological stage could be better option to solve the pollution problem faced by textile industry today.
Abstract ID 0045
Development of X-Ray Comupte Tomography Readable Normoxic Polymer Gel Dosimeter
K.Srinivasan 1 , E.J.J.Samuel 2 and V.Poopathi 1
1 Department of Medical Physics, RST Regional Cancer Hospital and Research Centre, Nagpur. 2 Department of Photonics, Nuclear and Medical Physics division, SAS, VIT University, Vellore
Gel dosimeter is the radiologically soft tissue equivalent and it measures the radiation dose distribution in 3D. However it has some limitations such as ion diffusion in Fricke gel and toxicity problem in polymer gel system. Commonly, gelatin is the gelling agent in both of the dosimeters but it is less thermostable and hence loses the dosimetric information. Magnetic resonance imaging (MRI) technique is commonly used for readout of the gel dosimeter. However, due to rare accessibility of MRI scanners to radiotherapy clinics and time consuming nature of the imaging process, this technique is scarcely used. In the present work, we are introducing high thermostable and relatively less toxic polymer gel dosimeter which can be analysed using X-ray Computed tomography (CT) scanner to study the dose response behavior. Normoxic hydroxyethyl methacrylate (HEMA) polymer gel was prepared and irradiated in 60 Co gamma ray beams with different doses ranging from 2 to 10 Gy. The gel dosimeter vials were scanned in the dual slice X-ray CT scanner and mean Hounsfield Unit (HU) were measured. Our result suggests that the gel dosimeter with 0.4% of the Gellan gum is having higher pre-irradiation stability in comparison to its higher concentrations. The dose response curve (dose Vs HU curve) was found to be linear with a root mean square value (R 2 ) of 0.9964. Average sensitivity of the dosimeter is about 1.3 HU/Gy. The optimum X-ray CT scanning parameters were found to be 130 kVp, 200 mA and 5 mm slice thickness. The thermal stability of the dosimeter was also verified and it was observed to be reasonable. However, further study is needed for clinical dosimetry using this gel dosimeter.
Abstract ID 0049
Spectrophotomeric Analysis of Hemagic Polymer Gel Dosimeter
K.Srinivasan 1 , E.J.J Samuel 2 and Deenaa titus 2 , V.Poopathi 1
1 Department of Medical Physics, RST Regional Cancer Hospital and Research Centre, Nagpur, 2 Department of Photonics, Nuclear and Medical Physics division, SAS, VIT University, Vellore
In radiation therapy, real three dimensional dosimeter is required to verify the planned dose distribution where the steep dose gradient exists such as SRS, SRT and IMRT techniques. One dimensional ion chamber and two dimensional film dosimeters are not a correct choice for such measurement. Gel dosimeter is the only choice for real 3D measurement it have number of advantage include soft tissue equivalent. In this work, we are analysing the dose response of HEMAGIC polymer gel dosimeter. Radiation sensitive polymer gel is prepared according to the literature. Gel is poured into the plastic cuvette and covered with aluminium foil in order to avoid autopolymerisation then kept in 4°C for gelling purpose. Dosimetric cuvette is irradiated with 6 MV X-rays from the medical linear accelerator with dose ranging from 2 to 14 Gy at 5 cm depth. Powerful double beam UV-visible spectrophotometer is used to study the optical absorbance.Our result recommended that, light is scattered due to the polymer cloudiness of the irradiated gel dosimeter. The absorbance is located around four different wavelengths such as 405.3 nm, 405.5 nm, 405.7 nm and 406.3 nm. In this particular wavelength absorbance is directly proportional to the radiation absorbed dose. Linear dose response was absorbed up to 12 Gy after it becomes saturated at 405.3 nm and 406.3 nm. Optical analysis of HEMAGIC normoxic polymer gel dosimeter was performed. Linearity was found that R 2 = 0.98648, R 2 = 0.98893 at 405.3 and 406.3 nm respectively. So such wavelengths may be suitable for dose measurement.
Abstract ID 0051
Emerging Paradigm in Radiobiology in Concept and Practices of Hypo Fractionated Conformal Radiotherapy
S. P. Mishra 1 , Anoop Kumar Srivastava 1 , Madhup Rastogi 1 , Rohini Khurana 1 , Asawari Pawaskar 2
1 Department of Radiation Oncology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, 226010; 2 Dept. of Radiotherapy, Curie Manavata Cancer Centre, Near Mumbai Naka, Nashik
The recent radiobiological concepts and innovations have provided tools to practice hypo fractionation in conformal Radiotherapy settings viz. SRT, SBRT and SRS and empower the medical fraternity to deliver curative doses in few (1-5) sittings. SBRT is utilized both for curative and palliative intent. SBRT and SRS have the connotation of "surgery" and were designed to produce ablation of tumour in single sitting as was plausible in surgical procedures. This study has been performed in clinical setting by creating the treatment plan in dynamic conformal arc mode as the treatment delivery technique; with add on collimator APEX system having 56 pairs of 2.5 mm each as treatment unit. Photon beam energy selected for the study was 6 MV. Various number of treatment arcs were applied depending upon the location of the PTV. The PTV was prescribed a total dose of 60 Gy in five fractions. Accordingly, patient safety is an over-riding factor when delivering an SBRT programme, so assiduous quality assurance programmes were kept in place with a professional approach. SBRT uses non-conventional fractionation regimen. It's radiobiological ingredients are therefore at variance with conventional fractionations. It is important, therefore, to fully consider the biological and physical factors influencing tumor cell killing when evaluating hypo fractionated SBRT treatment regimen. Plan objectives were set in conformity with ICRU-83 and AAPM 101 and the outcomes were assessed in conformity with these recommendations. The use of extreme hypofractionation means that the consequences of any single error would be consequently greater. The radiobiological parameters have been worked out to establish the equivalence of fractionation using various models and its applications will be demonstrated.
Abstract ID 0053
X-Ray Attenuation Coefficient of Various Metals in ICRU-44 Breast Tissue
K.Srinivasan 1 and E.J.J.Samuel 2
1 Department of Medical Physics, RST Regional Cancer Hospital and Research Centre, Nagpur; 2 Department of Photonics, Nuclear and Medical Physics Division, SAS, VIT University, Vellore
The challenging task of radiation therapy is to increase the therapeutic efficiency with minimum complication to surrounding normal tissue. Hence, addition of metal nanoparticles which differentiates the radiation effect between normal and tumour tissue is generally employed. High atomic number nanoparticle enhance the Compton and photoelectric effect resulting in production of secondary electrons. In the present study, we are calculating the mass attenuation coefficient and mass absorption coefficient of various biocompatible metals in ICRU - 44 Breast tissues. We are choosing five biocompatible metals such as Gold, platinum, Hafnium, Gadolinium and silver. WinXCOM database are used to generate the mass attenuation and mass absorption coefficient of metal and ICRU 44 Breast tissue over the energy range of 1 KeV to 20 MeV. Simple additivity is used to calculate the coefficient at 0.1% of metal and 0.9% of Breast tissue component. Our results suggest that, higher dose enhancements of all the metals occur between the energy of 3 KeV to 200 KeV. Among the five different metals, gold shows highest dose enhancing properties in the energy of 15 KeV. Silver deviated from the other metals, it shows higher dose enhancement in the energy of 31 KeV. We conclude that radiation dose enhancing properties of various metals in the ICRU 44 tissue is gold > Platinum > silver > Hafnium > Gadolinium. Nano sized metals may be used to enhance the tumour dose thus giving emergence to Nanoparticle enhanced X-ray therapy. Further practical research work is needed for clinical implementation.
Abstract ID 0054
Distribution of Radiocesium and Dose Estimation Studies Related to Fukushima Daiichi Nuclear Power Plant Accident
Project for Environmental Dynamics and Radiation Effects, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan
The nuclear accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) triggered by earthquake generated tsunami on March 11, 2011, caused massive contamination of radionuclides ( 131 I, 134,137 Cs, etc.) in Japan. In the environment, radiocaesium isotopes ( 134,137 Cs) and 90 Sr have long-lasting presence due to their long-lived half-life. Long lived radionuclides deposited on soil can cause an enhanced radiation exposure even after many years and depending upon environmental conditions can be mobilized to aquatic systems. Therefore, the assessment of the fate and transfer of these radionuclides in the soil water system is very important for radiation protection and dose assessment. In addition, a lot of radiation and radioactivity measurements have been conducted mostly in outdoor air and included the assumption that people stayed outdoors all day. The UNSCEAR 2013 report, published in April 2014, well summarizes the doses due to the Fukushima accident. The report estimates effective doses and thyroid doses for 1-y and 10-y children as well as adults. This paper will briefly mention the doses summarized by the UNSCEAR report. In addition, this paper will review some information including articles or official announcements not cited in the UNSCEAR report. Topics of the information were categorized as follows: (1) thyroid dose estimation by simulation and simultaneous measurement of indoor and outdoor radionuclide concentrations (2) internal dose: whole-body counting results in Fukushima Prefecture and caesium intake estimation by food analysis, and (3) external dose. Radiation monitoring data as well as radiation education should be one of the input bases for adequate and effective risk management.
Abstract ID 0055
Characterization of Gamma Ray Induced Zinnia Elegans var Dreamland Mutants Through Rapd Markers
Pallavi B 1 , Shashikiran Nivas 1 , Smitha Hegde 2
1 Laboratory of Applied Biology, St Aloysius College, Mangalore - 575003; 2 Department of P.G studies and Research in Biotechnology, St Aloysius College, Mangalore - 575003
Induced mutations play a major role in the development of new and novel plant varieties with improved plants traits. According to the International Atomic Energy Agency mutant varieties database, 3200 mutant varieties of 170 different plant species were officially released worldwide. Of these 24% represent ornamental plants. Therefore, induction of mutations through radiation has become a very important method in ornamental plant breeding. The objective of the present study was to induce mutation in Zinnia elegans var. Dreamland (Pink), an important ornamental plant by treating the seeds with three gamma radiations (75 Gy, 100 Gy and 125 Gy) and the analysis of genetic variations among the mutants compared to the parent plant using RAPD. The genetic variability was determined using Ten RAPD primers. Gamma radiations used in the study could induce change in flower colour (White, orange, Yellow) and flower form (single whorl, double whorl and absence of ray florets) in mutant plants.
Abstract ID 0058
Seasonal Variations in Terrestrial Gamma Radiation Along River Ganges and Implications to Public Health Risk
P. Sharma 1,2 , P. K. Meher 2,3 , K. P. Mishra 2,4
1 Department of Biotechnology and Microbiology, Saii College of Medical Sciences and Technology, Kanpur, U.P., India; 2 Division of Life Sciences, Nehru Gram Bharati University, Allahabad, U.P., India; 3 MATS School of Biological and Chemical Sciences, MATS University, Raipur, C.G., India; 4 Ex-Head, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Center, Mumbai, India
Measurement of exposure to terrestrial gamma radiation dose and determination of associated health hazard at river bank is of major importance due to the increasing tourism, bathing festivals and mythological beliefs. Present study was focused on measurement of absorbed dose rates as function of seasonal variation at designated locations along Ganges river in India. Portable dosimeter (plastic scintillation counter) was used for the measurement of absorbed dose rates. Subsequently, annual effective dose (AED) and excess lifetime cancer risk (ELCR) were calculated by the standard procedure. Results showed absorbed dose rates for Pre-monsoon ranged from 89.7 ± 4.03 to 115.0 ± 7.81 nSv/h with an average of 105.54 nSv/h. Post-monsoon measurements yielded values from 81.0 ± 7.00 to 105.6 ± 5.75 nSv/h with an average value of 90.8 nSv/h. Calculated average AED for Pre-monsoon period was found to be 0.13 mSv/y. Whereas, 0.11 mSv/y was the AED for the post-monsoon period. Furthermore, the calculated average ELCR values for pre-monsoon and post-monsoon were found to be 0.488 × 10−3 and 0.418 × 10−3 , respectively. This study reports significant seasonal variations in the terrestrial gamma radiation doses along the long stretch of Ganges river.
Abstract ID 0059
Development of a Colorimetric Protocol for Thorium Estimation and Localization in Liver Cells and Tissues
Rakhee Yadav 1,3 , Amit Kumar 1,3 , Manjoor Ali 1 , Sangita Dhara 2 , N. L. Misra 2,3 and B. N. Pandey 1,3
1 Radiation Biology and Health Sciences Division, 2 Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085; 3 Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094:
Thorium estimation is routinely done by various analytical methods (such as ICP-MS, ICP-AES). Most of these methods are time-consuming and require large volume of samples, hence, not very convenient and suitable for biological samples. Moreover, these methods are based on digestion of cell/tissue and hence could not provide information about sub-cellular or regional distribution at tissue level. Hence, we have standardized arsenazo based colorimetric method for thorium estimation/localization in cells and tissues. The results showed linearity with concentration of thorium nitrate within range of 1 to 50 mM. The lowest detectable concentration for thorium ( 232 Th) by this method was found to be 1 mM. To validate the results, the concentration of 232 Th was also estimated by total reflection X-ray fluorescence (T-XRF) method, which showed good correlation with arsenazo method. At these conditions, arsenazo method was found to be specific to thorium but not to Uranium and Cerium. The colorimetric method was further applied on 232 Th-treated human liver carcinoma cells (HepG2 cells) and mice liver tissues obtained after intravenous injection of 232 Th. Microscopy results showed that HepG2 cells treated with Thorium (50 mM) showed green colour, which was very distinct from controls. At sub-cellular level Th seems to get localized to mitochondria and nucleus. The liver tissue sections from Th-treated mice showed green colour zones suggesting thorium localization to some cell types in liver tissue. These results suggest that arsenazo based colorimetric protocol provides an easy, quick, specific and economic method for thorium estimation/localization in biological samples.
Abstract ID 0060
Protein Phosphorylation and Radioresistance in Deinococcus radiodurans
Y. S. Rajpurohit and Hari S. Misra
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai-400085
Deinococcus radiodurans R1 is better known for its extraordinary resistance to the lethal and mutagenic effects of DNA damaging agents including ionizing radiations and dessication. These phenotypes are attributed to highly efficient DNA double strand break repair and oxidative stress management. Unlike many bacteria, D. radiodurans does not benefit from the classical SOS repair mechanisms of prokaryotes, as it lacks LexA mediated transcriptional activation of SOS regulon genes; a sole DNA damage inducible response mechanism characterized in prokaryotes. Our recent finding suggests the involvement of eukaryotic type Ser/Thr/Tyr protein kinase (eST/YPK); RqkA in DNA double strand break repair and gamma radiation resistance of this bacterium. We demonstrated that some native DNA repair proteins acts as phosphosubstrates for RqkA kinase and their phosphorylation play important role in regulating their role in radiation resistance. Our finding suggests the existence of eST/YPK mediated an alternative DNA damage response mechanism in this prokaryote.
Abstract ID 0061
Significance of γ-H2AX Foci Baseline Frequency in Radiation Triage
Venkateswarlu Raavi , Solomon FD Paul, Perumal Venkatachalam
Department of Human Genetics, Sri Ramachandra University, Porur, Chennai-600116
Since the discovery of radiation, the application of radiation and radioactive material has increased in many fields. While, enjoying the benefits of radiation applications, protection for the workers becomes a challenging task. The occupational exposure is monitored using TLD/film badge. In contrast, such information may not available to the public in unexpected scenario; nevertheless, knowledge on the dose received by an exposed person is an important step towards the medical management. The Dicentric Chromosomal (DC) assay remains a "gold standard'; because of specificity to radiation. However, the limitations associated with DC leads to search for rapid and reliable alternatives such as γ-H2AX foci assay. Radiation triage is highly reliable, provided the base line frequency of γ-H2AX foci is known for the population before exposure. This is because, unlike the DC assay an inter-individual variability was observed. Therefore we established a base line frequency of γ-H2AX foci in healthy individuals (n = 130) of south Indian population differing in their sex, age, and occupation. Further, the kinetics of X-irradiation induced γ-H2AX foci and the influences of baseline on the dose response curve were investigated. The baseline frequency (0.042 ± 0.005), is significantly different from other populations. Age is the major factor influencing the γ-H2AX foci frequency. The dose response curve coefficients deviated significantly (p < 0.05) when substituted with the baseline frequency from different age groups. To conclude, the age factor should be taken into account when employing the γ-H2AX foci for radiation triage and dose estimation.
Abstract ID 0062
Inhibition of MAPK1/3 and Akt Pathways Equally Enhance Radiation Sensitization of B16F10 Melanoma Cells
Bhuvanesh Sukhlal Kalal 1 , Dinesh Upadhya 2 , Vinitha Ramanath Pai 1
1 Department of Biochemistry, Yenepoya Medical College, Yenepoya University, Mangalore, India 2 Institute for Regenerative Medicine, Texas AandM University Health Science Center, Temple, TX, USA.
Radiation can activate PI3K/Akt and/or MAPK/ERK signaling pathways that play an important role in cell survival after radiation therapy in cancer. This study was designed to assess the radiation sensitizing effect of MAPK1/3 and AKT pathway inhibitors, U0126 and LY294002, on B16F10 mouse melanoma cells. The B16F10 cells were treated with 10 and 20 µM concentrations of MAPK1/3 and AKT pathway inhibitors, U0126 and LY294002, respectively for 24 hrs in triplicates. Cells were exposed to single dose of 2.0 Gy or 3.0 Gy electron beam irradiation and incubated with inhibitor/s for the next 24 hrs. The radiation sensitizing ability was analyzed and compared with controls using TUNEL assay and quantified using flow analysis. Treatment of cells with 10 µM concentrations of U0126 or LY294002 for 24 hrs prior to 2.0 Gy radiation exposure showed little increase in cell death. However, at 20 µM concentration, both drugs at similar conditions produced 1.4 fold increase in cell death compared to the 2.0 Gy radiation control. Further, increase in radiation dose to 3.0 Gy with the pretreatment of same drugs showed approximately 1.5 fold increase in cell death compared to 3.0 Gy radiation control. However, combined pretreatment with 20 µM of U0126 and LY294002 followed by 3.0 Gy radiation failed to show cumulative radiation sensitization effects. Overall, the study concludes that inhibition of MAPK1/3 and AKT by U0126 and LY294002 equally enhance radiation sensitization in B16F10 mouse melanoma cells. This argues that MAPK1/3 and AKT pathways redundantly enhance tumor cell survival and proliferation upon radiation exposure.
Abstract ID 0063
Chromosome Aberrations in Subjects Receiving Low Doses of Ionizing Radiation During Medical Imaging
Karthik Kanagaraj 1 , Safa Abdul Syed Basheerudeen 1 , Sakina Murtaza 1 . Panneer Selvam 2 , Sudha Pattan 2 , P. Venkatachalam 1
1 Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, India - 600 1162; b Department of Radiology and Imaging Science, Sri Ramachandra University, Porur, Chennai, India - 600 116.
Low energy X-rays (kVp) are widely used in medical field for imaging, diagnostic radiology and therapy. An increase in the utility of imaging procedures and concomitant increase in the public exposure to the low doses of ionizing radiation has been documented in the literature. Significant publications have emerged out on the frequency of chromosomal aberration (CA) due to low dose of ionizing radiation exposures from the occupational radiation workers; generally the occupational workers are monitored with their personnel monitoring devices for the quantum of exposure. Despite the quantum of publications, sufficient amount of data was not available to clearly understand the biological effects of low doses of ionizing radiation. An alternative source of information to collect data for such low doses of exposure is personals/subjects undergoing different kinds of imaging modality. Of the different imaging modalities, the computed tomography (CT) is normally used to diagnose many health ailments. We made an attempt to investigate the CA frequency in subjects who had undergone CT imaging procedures (n = 27) and personals involved in interventional radiological procedures (n = 26); the obtained frequency was compared with that obtained from age and sex equivalent healthy volunteers. The frequency obtained from the interventional personnel and subject who had undergone CT scan was (0.0105 ± 0.001) and (0.009 ± 0.01) which shows a significant increase in aberration when compared to that of healthy volunteers (0.004 ± 0.001). The significance of the DNA damages will be discussed.
Abstract ID 0064
Estimation of Absorbed Dose and Its Biological Effects in Subjects Undergoing Neuro Interventional Radiological Procedures
Safa Abdul Syed Basheerudeen 1 , Vinodhini Subramanian 1 , Santosh Joseph 2 , Paneer Selvam 2 M.T.Jose 3 , O. Annalakshmi 3 , Perumal Venkatachalam 1
1 Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, India - 600 116. 2 Department of Radiology and Imaging Science, Sri Ramachandra University, Porur, Chennai. 3 Radiation Safety Section, Radiation Safety Division, Indira Gandhi Center for Atomic Research, 603102 Kalpakkam, India.
Radiological imaging has many applications due to its non-invasiveness, rapid diagnosis of life threatening diseases, and shorter hospital stay which benefit patients of all age groups. However, these procedures are complicated and time consuming, which use repeated imaging views and radiation, thereby increasing patient dose, and collective effective dose to the background at low doses. The effects of high dose radiation are well established. However, the effects of low dose exposure remain to be determined. Therefore, investigating the effect on medically exposed individuals is an alternative source to understand the low dose effects of radiation. The ESD (Entrance Surface Dose) was recorded using Lithium borate based TL dosimeters to measure the doses received by the head, neck and shoulder of the study subjects (n = 70) who underwent procedures like cerebral angiography, coiling, stenting and embolization. Peripheral blood lymphocytes of study subjects at time points 0 th h, 2 h and 24 h post exposure was used to assess for chromosomal aberrations (CA) and micronucleus (MN) assays. The overall measured doses ranged from 49.01 to 220.99 mSv for head, 46.31-191.55 mSv for neck and 7.83-155 mSv for shoulder. The mean CA frequency observed in 2 h (0.070 ± 0.0001) and 24 h (0.083 ± 0.0002) post exposure in the study subjects was found to be significantly higher than that seen in the control subjects (0.005 ± 0.0002) (p < 0.001) similarly, MN frequency in 2 h (0.093 ± 0.0003) and 24 h (0.0116 ± 0.0001) post exposure was significantly higher when compared to control subjects (0.0075 ± 0.0002) (p < 0.001). The overall results suggest interventional imaging delivers a considerable amount of radiation dose that induces DNA damages to patients.
Abstract ID 0066
Are the Risk and Benefits of Medical Radiation Exposure Underestimated?
Department of Human Genetics, Sri Ramachandra University, Porur, Chennai-600 116
Radiation in medicine contributes significantly not only towards early detection of disease but also to reduce the incidence. Further, as radiological examinations are non-invasive, free of pain to the patient, and diagnosis is fast and reliable, their use is increasing. In turn, the population exposure to diagnostic and therapeutic ionizing radiation is likely to increase worldwide and about 14% from man-made sources. The unique features of radiation in medicine are that doses exposures range from up to few mGy for most diagnostic examinations to many tens of Gy for treatment of cancer. Although diagnostic procedures provide great benefits that the risk of developing stochastic effects resulting from their use is under active investigation. The issue is further challenged by recently reported radiobiological phenomena like adaptive response, bystander effects, low dose hypersensitivity, delayed genomic instability, hormesis and induced DNA repair. Thus, it appears that the effect of low dose radiation are rather complex on the effects of low dose radiation than predicted based on the high dose exposures. However, the effective doses of diagnostic X-ray examinations depend upon machine parameters, procedures and biological machinery of the individual determines the health effects. Data's obtained following exposures to very low dose and dose rate exposures received during imaging radiological procedures exposed in-vivo and therapeutic doses will be discussed in terms of the potential benefits and its associated risk.
Abstract ID 0067
Radioprotective and Antiproliferative Activity of Viscum album in Lymphocytes Exposed to Gamma Radiation
Syed Murthuza 1 , BK Manjunatha 1 , Rahul Checker, Deepak Sharma, S Santosh Kumar 2
1Department of Biotechnology, The Oxford College of Engineering Bommanahalli, Bengaluru-560068, 2 Radiation Biology and Health Sciences Division, Bio-Medical Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
In the present study, the effect of Viscum album methanolic (VaM) extract and Methanol: Hexane (VaMH) fraction against gamma radiation induced radioprotection and mitogen proliferation in mice splenic lymphocytes was examined. Both VaM and VaMH inhibited the in vitro lymphocyte proliferation induced by concavalin A (Con A) in a dose dependent manner at higher dose of 100 μg and at lower doses 10 μg, also exhibited effective cell growth inhibition by inducing cancer cells to undergo G2/M phase arrest and apoptosis. Whereas the generation of ROS acts as a mediator in Both VaM and VaMH induced cell growth inhibition. On the contrary, it significantly inhibited the radiation-induced DNA damage in splenocytes as indicated by decrease in DNA fragmentation. In-vitro radioprotective activity was studied in plasmid pBR322 DNA and their effect on gamma radiation induced DNA damage. Estimation of apoptosis, Cell viability by Trypan blue, Mitogen induced proliferation, measurement of ROS, DNA Laddering and pBR322 DNA damage study was also carried out. Most important finding of the present study was VaM and VaMH contains naturally occurring flavonoids and phenolic compound, effectively protected cells against radiation and prolonged the survival of mice exposed to a lethal dose of γ-radiation and it also showed strong anti-proliferative affect. Several natural products have been shown to protect cells against radiation damage by virtue of their antioxidant properties.
Abstract ID 0068
Toxicity to Microbes as a Bio-Indicator for Uranium Contaminated Drinking Water
P. K. Meher 1,2 , P. Sharma 2,3 , K. P. Mishra 2, 4, 5
1 MATS School of Biological and Chemical Sciences, MATS University, Raipur, C.G., India; 2 Division of Life Sciences, Nehru Gram Bharati University, Allahabad, U.P., India; 3 Department of Biotechnology and Microbiology, Saii College of Medical Sciences and Technology, Kanpur, U.P., India; 4 Radiation Biology and Health Sciences Division, Bhabha Atomic Research Center, Mumbai, India; 5 International Center of Scientific Research, JVB University, Mumbai, India
Uranium contaminated drinking water is a major concern for human health and environment. We have determined the concentration of uranium in drinking water from various geographic places using LED induced fluorescence method and have further extended our studies to find response of microbes present in water to uranium. Commonly found water bacteria E. coli and B. cereus were selected for developing possible bio-indicator to evaluate uranium contaminated drinking water. Growth pattern of both the microbes were studied with different uranium concentrations (0, 25, 50, 100, 250, 500, 1000 μg/l) and incubation times (24, 72, 144, 216 h). Results showed a notable bacterial toxicity to E. coli0 between 500 to 1000 μg/l concentrations of uranium. On the other hand, B. cereus showed significant bacterial toxicity between 250 and 500 μg/l concentration of uranium. Responses of bacterial toxicity were also observed at different incubation time. Preliminary results allowed us to conclude that B. cereus showed greater sensitivity to uranium than E. coli. It appears that B. cereus could be a potential bio-indicator for uranium contamination. Further deeper studies are in progress to establish the biochemical and biomolecular mechanisms that may be associated with the microbes for development of a bio-indicator for uranium contamination in water.
Abstract ID 0070
Impact of Long-Term Radiation Exposure on Aquatic Biota Within the Chernobyl Exclusion Zone: 30 Years after Accident
D.I. Gudkov 1 , N.A. Pomortseva 1 , N.L. Shevtsova 1 , E.V. Dzyubenko 2 and A.B. Nazarov 31
Institute of Hydrobiology, Geroyev Stalingrada Ave. 12, 04210 Kiev, Ukraine, 2 G. Skovoroda Pereyaslav-Khmelnitsk State Teacher Training University, Ukraine; 3 Chernobyl Specialized Enterprise, Chernobyl, Ukraine
Self-purification of closed water bodies within the Chernobyl exclusion zone (EZ) is an extremely slow process. Therefore, ecosystems of the majority of lakes, dead channels and crawls possess high levels of radionuclide contamination of all components. Along with natural decontamination processes in aquatic ecosystems such as physical decay of radionuclides and their water transport outside the EZ, there is a change of physical and chemical forms of radioactive substances in soils of catchment areas, their transformation and transition in the mobile and bioavailable state, washout to the closed aquatic ecosystems and accumulation by hydrobionts. This essentially deteriorates the radiation situation in closed aquatic ecosystems, which are some kind of "storage system" of radioactive substances in the EZ and results in increase of radiation dose to aquatic species and manifests in a variety of radiation effects at different levels of biological systems. We established dose-related effects in hydrobionts of lakes within the EZ which indicates a damage of biological systems at subcellular, cellular, tissue, organ, organism and population levels as a result of chronic exposure to low doses of ionizing radiation. The rate of chromosomal aberrations in cells of aquatic species, many-a-times exceeds the level of spontaneous mutagenesis level to aquatic biota. Increased levels of chromosome damages may be a manifestation of radiation-induced genetic instability, which is one of the main mechanisms for the protection of living organisms from exposure to stressors with subsequent implementation at higher levels of organization of biological systems.
Abstract ID 0072
Measurement of Mass Attenuation Coefficient and Its Photon Interaction Derivables in Some Skeletal Muscle Relaxants
Department of Physics, Government College for women, Kolar, Karnataka, India
We have measured the mass attenuation of some commonly used skeletal muscle relaxants such as tubocurarine chloride, gallamine triethiodide, pancuronium bromide, suxamethonium bromide and mephenesin for various gamma sources of energy ranging from 84 keV to 1330 keV ( 170 Tm, 57 Co, 141 Ce, 203 Hg, 51 Cr, 113 Sn, 22 Na, 137 Cs, 60 Co, 22 Na and 60 Co). The measured values agree with the theoretical values. The effective atomic numbers (Zeff ) and electron density (Ne ) of commonly used skeletal muscle relaxants for total and coherent, incoherent, photoelectric absorption, pair production in atomic and nuclear field photon interaction have been computed in the wide region 1 keV to 100GeV using an accurate database of photon-interaction cross sections and the WinXCom program. The significant variation of Zeff and Nel is due to the variations in the dominance of different interaction process in different energy regions. A comparison is also made with the single values of the Zeff and Nel provided by the program XMuDat. We have also calculated CT numbers, kerma values relative to air and dose rate for relaxants which are also not remaining constant with energy. The computed data of CT numbers in the low energy region helps in visualizing the image of the biological samples and precise accuracy in treating their inhomogenity in medical radiology. The calculated kerma values relative to air and dose rate for relaxants are useful in radiation medicine.
Abstract ID 0074
Determination of Molar Extinction Coefficient and Total Molecular Cross Section of C, H, N, O Based Compounds
S. S. Pawar , P. S. Kore and P. P. Pawar
Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431 004, (M.S)
The present study aimed to determine the effective atomic and electronic cross section of some medically useful amino acids. These parameters are used to characterize the radiation response in radiation dosimetry, radiation biology and radiological applications with research context. Appropriate values of these physical parameters gives essential data in health physics which have been calculated for some amino acids; DL-Aspartic Acid-LR (C 4 H 7 NO 4 ), L-glutamine (C 4 H 10 N 2 O 3 ), L-Asparagine Monohydrate (C 4 H 9 N 3 O 2 H 2 O) were measured using NaI (Tl)-based gamma spectrometry. The radioactive 57 Co, 133 Ba, 137 Cs, 60 Co and 22 Na having energy range 122 to 1500 keV are used in this study. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against Win-XCom program.
Abstract ID 0076
Radioprotective Effect of Punica granatum Extract in Head and Neck Cancer Patients
Amulya T M 1 and Satheesh Kumar Bhandary 1
1 K S Hegde Medical Academy, Nitte University, Deralakatte, Mangalore
To study protective role of pomegranate extract on radiation induced dermatitis and mucositis in head and neck cancer patients, a prospective, clinical, double blind case control study was carried out. 60 patients (30 active and controls) undergoing radiotherapy for head and neck cancer were studied for 12 months. Patients in study group were given whole fruit pomegranate extract. Each capsule contained 300 mg of whole fruit extract, each capsule contains 40% polyphenols and 27% punicalagin. Each patient was given 2 capsules every day for a period of 6 to 7 weeks. The skin and mucosal changes was graded according to the Acute Radiation Morbidity Scoring criteria (RTOG) for skin and mucous membrane. Among the 30 patients who received the pomegranate extract, 27 had grade 1, 2 had grade 2 and 1 had grade 3 dermatitis. Whereas those who did not receive the extract, 20 had grade 2 dermatitis, 7 had grade 3 dermatitis and 3 had grade 4 dermatitis. Among the 30 patients who received the pomegranate extract, 10 had grade 0, 17 had grade 1 and 3 had grade 2 mucositis. Whereas of those who did not receive the extract, 21 had grade 2 mucositis, 9 had grade 3 mucositis. The results were statistically significant. Our study is one of the first study in humans to demonstrate the effectiveness of pomegranate extract in preventing radiation dermatitis and mucositis.
Abstract ID 0079
Evaluation of Antioxidant, Antiinflammatory and Hematopoietic Activity of Pterocarpus Santalinus
G.EN. Hanuma Kumar and M. Balaji
Department of Biochemistry, S.V. University, Tirupati
With great leaps in science and technology, the usage of radiation based technology/instruments has increased substantially in recent decades as a result of which man is being increasingly exposed to different kinds of radiations. In the present work, the radioprotective activity of Pterocarpus santalinus, an endemic species grown in Seshachalam Hill ranges of Eastern Ghats is being evaluated. The Heartwood of P. santalinus was collected, powdered and 90 % ethanolic extract was prepared. After fractionation with different solvents, the chloroform fraction was collected from which different fractions were isolated through silica gel column, and to them phytochemical analysis, TLC and LCMS were performed to confirm the presence of bioactive constituents. Antioxidant, anti-inflammatory and hematopoietic activities were evaluated in the presence and absence of P. santalinus fractions (PSF-2 and PSF-3) in control and UV-irradiated Swiss albino mice. Phytochemical analysis revealed the presence of bioactive compounds like Lignans, Coumarins, Alkaloids etc. PSF-2 and PSF-3 showed the presence of Pterocarpol, Santalin, Cryptomeridol etc., Pretreatment with these factions have substantially protected the mice from UV-induced alterations. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Nitro blue tetrazolium chloride (NBT) and 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays showed the potent antioxidant activity of PSF-2 and PSF-3. These fractions also considerably limited the UV-induced lipid peroxidation. PSF-2 and PSF-3 also demonstrated significant anti-inflammatory activity as evident from Cyclooxygenase-1 (Cox-1) and TNF alpha assays. Analysis of blood showed that mice administered with PSF-2 and PSF-3 have maintained near normal blood cell counts demonstrating hematopoietic activity.
Abstract ID 0082
Radio Labeled Polymeric Magnetite Nanoparticles Targeted against Human Glioma in Mouse Orthotopic Xenograft Model
Suma Prabhu 1 , JayantSastri Goda 2 , Bhabani Shankar Mohanty 2 , Srinivas Mutalik 3 , Pradip Chaudhari 2 , Nayanabhirama Udupa 4 and Bola Sadashiva Satish Rao 1
1 School of Life Sciences, Manipal University, Manipal- 576 104, Karnataka; 2 Advanced Centre for Treatment, Education and Research in Cancer, Tata Memorial Centre, Kharghar, Navi Mumbai - 410 210, Maharashtra; 3 Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal - 576 104, Karnataka, 4 Research (Health Sciences), Manipal University, Manipal - 576 104, Karnataka, India.
Therapy for malignant gliomas are hindered by a number of limiting factors such as blood brain barrier, complexities in therapeutic drug delivery specifically to the tumor cells, highly invasive quality of glioma and drug resistance. Nanotriggers based imaging and therapeutic agents are functioning to deliver versatile payloads with favorable pharmacokinetics and capitalize on molecular and cellular targeting for enhanced specificity, efficacy and safety. Our study formulated a polymeric magnetite based nanoparticle, which focuses on an efficacious targeted delivery to the tumor, in an intracranial orthotopic glioma model. Multifunctional polymeric magnetite nanoparticles were engineered with an anticancer drug (Temozolomide) by a ligand transferrin/polysorbate-80 to cross the blood brain barrier along with an additional glioma cell surface targeting by anti Nestin antibody. We established an orthotopic glioma xenograft model to determine the pharmacokinetics, bio-distribution and pharmacodynmics for pure drug, in comparison to that of the other formulations. An efficient uptake targeted to glioma using orthotopic mouse model, with a minimum drug release in plasma was seen. SPECT-CT imaging showed longer retention of 99m Tc labeled nano-trigger in the tumor. Further, pharmacodynamics visualized by CT scan and validated by IHC for proliferation markers indicated enhanced subsequent regression of tumor in both the formulations.
Acknowledgements: We thank Manipal University for Providing Dr. T.M.A. Pai Fellowship for Structured Ph.D. Program to the first author. We highly acknowledge ACTREC for facilitating small animal imaging facility.
Abstract ID 0083
Source Term Estimation of High Energy Proton Beams Using Fluka Monte Carlo Simulations
K. Biju 1 , D. S. Joshi 1 and T. Bandyopadhyay 1
1 Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085
Shielding assessment of proton therapy facilities by the analytical techniques requires inputs like the radiation attenuation length and source term. The secondary radiation field such as yield, ambient dose equivalent rates, produced by high energy protons ((p,xn) nuclear reactions) with accelerator materials or the patient are called as source term. The neutron yield also helps to quantify induced activity in the air in the accelerator structures. Depending on the treatment site, the proton beam energies used for the therapy varies from 70 MeV-230 MeV. This study calculates the neutron and photon yield and ambient dose equivalent rates from high energy proton beams of 70 MeV-250 MeV falling on iron and water targets using Monte Carlo simulations. FLUKA2011.2C code is used to simulate transport and interaction of protons in target based on modern physics models. The source term from an iron target can be a representative source term for evaluating the cyclotron vault shield and the same from a thick water target can be used for the treatment room. The energy distribution and directional distribution of the source term is also obtained which helps optimising lateral shielding. The photon source term is around 100 times lower than the neutron source term. The neutron ambient dose equivalent rate from iron target in the lateral direction is about 2.5 times lesser compared to forward direction with respect to the beam direction. Some of the results of this study have been compared with the values of IAEA TRS-283 Report (1988).
Abstract ID 0084
Evaluation of Biomedical Radiological Data of Bio-Molecules in Energy Range 122-1408 keV
P. S. Kore , B. M. Ladhaf, S. S. Pawar and P. P. Pawar
Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431 004, (M.S) India.
This work is to determine the radiological absorption, attenuation, cross section parameters such as mass absorption coefficient (mm), total absorption cross section (σtot), molar extinction coefficient (ε) and related cross section parameters; σm,en, men /r and Z eff which are convenient quantities used to characterize the radiation response of a multi-element material in radiation dosimetry, radiation biology and medical applications with research context. Accurate values of these physical parameters have been calculated for some polyketides namely; Erythromycin E (C 37 H 65 NO 14 ), Erythromycin B (C 37 H 67 NO 12 ), Pikromycin/Amaromycin (C 36 H 65 NO 12 ) using NaI(Tl)-based gamma spectrometry. Now-a-days, polyketides natural products find clinical utility as antibiotics, anti-parasitics, anticancer drugs. The comprehensive pharmacological polyketide activities give continued motivation to unravel biosynthetic mechanisms to enable the discovery of novel compounds for the benefit of human health society. Many of these have infamous food-spoiling toxins and some have important therapeutics for clinical use of drugs such as erythromycin, rapamycin and lovastatin etc. Many of these have important industrial applications in the food and pharmaceutical industries. The radioactive sources 60 Co, 52 Cr, 65 Zn, 131 I, 57 Co, 137 Cs, 152 Eu and 203 Hg having energy range 122 to 1408 keV are used in this study which are mostly useful in medical and health physics. The observed experimental and theoretical values were within good agreement with Win-XCom program.
Abstract ID 0086
Indium Foil - A Tool for the Absolute Measurements of Photo-Neutrons in Medical Linear Accelerator
Deepa Sathian 1 , Siji Cyriac 2 , Abdul Haneefa 2 , Mudit Beck1 , A.K. Bakshi 1 , M.M.Musthafa 3 , R. Ganapathi Raman 4 , T. Palani Selvam 1 and D. Datta 1
1 Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai - 400 094; 2 Nanavati Super Specialty Hospital, Vile-Parle, Mumbai - 400 056. 3 Department of physics, University of Calicut, Kerala;. 4 Department of Physics, Noorul Islam University, Kumaracoil, Thuckelay -629 180, Tamilnadu.
Neutron contamination in high energy medical linear accelerators operating at photon/electron mode, with energies above 10 MeV used in radiotherapy is a concern from the radiation protection point of view. Neutron activation of foils has been extensively used to determine the photo-neutron production in medical LINAC in recent times. The aim of the present study is the absolute measurements of these photo-neutrons using the Indium activation foil having both thermal and fast neutron cross-sections through the nuclear reactions 115In (n, γ) 116m In and 115 In (n, n') 115m In. Photo-neutron measurements as a function of depths in phantom, distances from field edge and at LINAC head for 15 MV photon beam from a Medical LINAC model Elekta Precise have been carried out in the present study. The total photon dose delivered was in the range of 100-200 Gy, field size of 30 × 30 cm 2 and a source to detector distance of 100 cm. Depth dose measurements indicate that, the maximum thermal and fast photo-neutron dose-rates are 2.13 μGy/Gy-photon at 3 cm depth and 15.7 mGy/Gy-photon at 0 cm depth respectively along the central axis. The thermal and fast neutron dose rates on the LINAC head are estimated as 0.16 μGy/Gy-photon and 49.3 mGy/Gy-photon, respectively. On the patient plane, the maximum thermal and fast photo-neutron dose rates are 0.12 μGy/Gy-photon at 50 cm distance from the field edge and 15.5 mGy/Gy-photon at the isocentre. The total neutron dose from photo-neutron is estimated to be 13.5 mGy/Gy-photon at 3 cm depth using indium foils. The photo-neutron dose received by a patient for a treatment dose of 50 Gy for a typical Intensity Modulated Radio Therapy (IMRT) case would be in the range of 600-700 mGy which is about 1% of the photon dose.
Abstract ID 0087
Correlation Between Micronuclei DNA Damage in Patient Receiving Radiotherapy and Low Dose Irradiated Blood Samples Using Linear Accelerator
S.P. Mishra 1 , Anoop K Srivastava 1 , Madhup Rastogi 1 , Rohini Khurana 1 , Rahat Hadi 1 , Kamal Sahni 1 , Shantanu Sapru 1 ,Shikha Tewari 2 , Nuzhat Husain 2 ,Kainat Khan 2
Department of Radiation Oncology 1 and Department of Pathology 2 , Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India
Need of a reproducible biological dosimeter for detecting the low doses has been a matter of investigation for quite some time. In this presentation, an attempt has been made to evaluate the micronuclei damage in irradiated blood sample vis-a-vis radiation delivered to cancer patient and to establish an in vitro model for studying the effects of low radiation doses (<1 Gy). ELEKTA infinity high energy Linear Accelerator (LINAC) having 6 MV photon, with kVCT facility was utilized for blood sample irradiation. The samples contained in the heparinised vial were provided a build-up of adequate water equivalent thickness for required energy using Wax bolus of 1.5 cm which also prevented any deformity in transportation and positioning. The dose calculation was performed with treatment planning system (Xio 3D v 5.0).The treatment plan data was transferred to the treatment unit using the record and verification system. The reproducibility of the dose to the sample was verified using 2D array of detectors and Film dosimetry system. The dose delivered was maintained within the tolerance limit of ±2%.The requisite monitor units for 0.1, 0. 25, 0.5, 1.0, 2.0 Gy were delivered and sample was transported to the Pathology department of the institute for further analysis on Microscopes. The micronuclei formation increased exponentially with the radiation dose and as low as 0.1Gy of radiations could induce micronucleus formation in lymphocyte cultures.
Abstract ID 0088
Biochanin a Enhances the Radiotoxicity in Colon Tumor Cells In Vitro
Abhay Puthli 1 ,2 , Reeta Tiwari 1,2 Sreedevi Balakrishnan 2 , and Kaushala Prasad Mishra 1,3
1 Department of Life Sciences, University of Mumbai, Mumbai 400 098, India, 2 Radiological Physics and Advisory Division Bhabha Atomic Research Centre, Mumbai, 400 085, India and 3 Nehru Gram Bharati University, Allahabad 211 002, India
Herbs and other plant-based compounds have increasingly been recognized as useful for the prevention and treatment of cancer. There exists enormous scope for screening and evaluation of herbal/plant products to develop an effective radiosensitizer and radioprotector that is relevant for cancer therapy. Anticancer agents that can effectively trigger the process of cell death in tumor cells need to be developed. This study describes the effect of the flavonoid biochanin A (BCA), administered alone or in combination with gamma radiation, on the growth of radioresistant human colon cancer HT29 cells in vitro. Proliferation studies were carried out using MTT assay with increasing concentration of BCA (1-100 µM) followed by gamma irradiation at a dose of 2 Gy. Induced reactive oxygen species, mitochondrial membrane potential, lipid peroxidation, and caspase-3 activation were measured by fluorescence assays and the magnitude of induced apoptosis in cells was evaluated by flow cytometry. Cellular DNA damage was determined by comet assay. Combined treatment caused a significant decrease in cell proliferation, a substantial increase in the generation of reactive oxygen species, enhanced lipid peroxidation, and increased mitochondrial membrane potential in treated HT29 cells compared with controls. Significantly enhanced apoptosis and DNA damage were found with a combination of drug and radiation treatments. Furthermore, it was found that combined treatment yielded an additive increase of caspase-3 in these cells. Our findings indicate that BCA acts as a remarkable pro-oxidant, significantly enhancing the radiotoxicity of colon cancer cells in vitro.
Abstract ID 0090
Estimation of 99m Tc-4+1 Benzylguanidine Complex Uptake in Tumor Xenografts using Micro-Spect
Shubhangi Mirapurkar , 1 Rani G., 1 P.R.Chaudhari, 2 Anupam Mathur, 1 Soumen Das, 1 Navin Sakhare, 1 H.D. Sarma, 3 S.S.Sachdev 1
1 Radiopharmaceuticals Program, Board of Radiation and Isotope Technology, Navi-Mumbai-400705, India; 2 Advanced Centre for Treatment, Research and Education in Cancer, Tata memorial Centre, Navi Mumbai-410210, India; 3 Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India.
131 I-labelled meta-Iodo benzyl guanidine (mIBG) is an established radiopharmaceutical used clinically for Neuroendocrine tumor (NET) imaging. However, the unfavourable imaging characteristics of 131 I accounts called for increased interest worldwide to develop a 99m Tc-substitute for the aforementioned application. In this respect, a new 99m Tc-analogue was synthesized which was evaluated in a tumor xenograft model and uptake was quantified using micro-SPECT imaging. A guanidine derivative bearing an isonitrile group ('1') at the meta position suitable for 99m Tc labeling via 99m Tc-'4+1' strategy was synthesized. This derivative was then radiolabeled with 99m Tc following the established 99m Tc-'4+1' labeling approach to yield the desired complex. The complex was then evaluated in nude female Swiss mouse bearing SK-N-SH neuroblastoma. About 200 µL (~8 MBq/215 µCi) of the radiolabeled preparation was administered via the tail vein and whole body SPECT images were acquired 1 h post-injection. The SPECT images were reconstructed using 60 iterations and data was analyzed and quantified using quantification software. The uptake of the tracer in the tumor was obtained by marking a region of interest (ROI) on co-registering with a CT image. Micro-SPECT image did not show any hot spot in the region of tumor, however, the standard uptake value calculated by marking ROI in the tumor was around 4% ID/g. Though the potentiality of the present tracer for neuroblastoma imaging could not be completely established, the micro-SPECT-CT image obtained provided the utility of the technique for semi-quantitative estimation of the distribution pattern in target/ non-target organs.
Abstract ID 0091
Effect of Gamma Radiation on Total Antioxidant Capacity, Total Lipid Concentration and Shelf Life of Finger Millet Flour
Lathika 1,2 , B. R. Manupriya 1 , S. L. Patil 2 , K. B. Shenoy 1 and H. M. Somashekarappa 3
1 Department of Physiology, K. S. Hegde Medical Academy, Deralakatte, Mangalore, 2 Department of Applied Zoology, Mangalore University, Mangalore, 3 Centre for Application of Radioisotopes and Radiation Technology, University Science Instrumentation Centre, Mangalore, Karnataka, India.
Food irradiation is the modern processing technology to extend the shelf life of food commodities. However, the common experience is that the food supplements prepared and supplied in bulk are susceptible to infestation and microbial spoilage. In this direction, the present study is an attempt to study the impact of gamma radiation on the shelf life, total antioxidant capacity and total lipid concentration of finger millet (Eleusine coracana L.) flour. Finger millet flour was procured from market. Flour samples of 50 g were taken in triplicates in a polyethylene pouch, air sealed and subjected to gamma irradiation doses ranging from 0.25 to 10 kGy and stored in polyethylene bags and plastic containers for a period of 1 year. Within 24 hours of irradiation, the samples were tested for moisture (2 ± 0.2%), total antioxidant capacity (0.12 ± 0.010 mg) and lipid concentration (15 ± 0.4mg). The same was repeated after 3, 6 and 12 months of storage. The results indicated that during 6 months storage period no insect infestation was observed in both irradiated non irradiated samples. But insect infestation was seen only in non irradiated samples during 7 th month of storage in polyethylene bag and in 10 th month in container. Estimation of total antioxidant capacity and lipid concentration indicates that there was no significant difference between irradiated and non-irradiated samples. Hence, it is concluded that radiation processing prevents food from insect infestation particularly of food items that need to be stored for long period and retains the nutrition and moisture of food products.
Abstract ID 0092
Study of Gamma Shielding Ability of a Novel Lead Free, Tungsten Oxide Filled Polymer Composites
M. R. Ambika and N. Nagaiah
Department of Physics, Bangalore University, Bangalore-560056, Karnataka, India
Lead based radiation shields are widely used in nuclear science and technology. Because of the heaviness and toxicity of lead, the invention of a novel, lead free radiation shielding material has been a thrust area in the field of radiation protection. Hence, polymer composites serve a better purpose for the same. The present study deals with the fabrication of a novel, light weight and lead free polymer composite radiation shields filled with tungsten oxide. Different concentrations of tungsten oxide upto 50% were incorporated into the unsaturated polyester resin by a simple open mould cast technique. The composites were then investigated for its shielding ability using a 3" x 3" NaI(Tl) gamma ray spectrometer for Cs-137 and Ba-133 gamma radiations. The density of the composites was determined using ASTM standards. The attenuation results show that, the linear attenuation coefficient increases with increase in the filler concentration and decreases with increase in energy and are found to be in the range 0.195-6.191 cm -1 , 0.096-0.267 cm -1 and 0.09-0.172 cm -1 for 80 keV, 356 keV and 662 keV respectively. The other shielding parameters such as mass attenuation coefficient and half value layer thickness (HVL) were also calculated. The HVL value for the maximum filled composite is found to be 0.11 cm, 2.59 cm and 4.01 cm for 80 keV, 356 keV and 662 keV respectively. The shielding performance of the polymer composites has been compared with that of conventional shielding materials. The study reveals that, the composites do perform well at all energies but excel in their shielding ability at low energy and hence can be used for gamma shielding applications.
Abstract ID 0093
Evaluation of Protective and Therapeutic Potential of Kinetin Intervention on Lipid Peroxidation in Mice Exposed to Sublethal Dose of Electron Beam Radiation
Vishakh R. 1 Shailaja S. Moodithaya 2 Suchetha Kumari N. 3 Ganesh Sanjeev 4
1 Central Research Laboratory, KSHEMA, Nitte University, Mangalore; 2 Department of Physiology, KSHEMA, Nitte University, Mangalore; 3 Department of Biochemistry , KSHEMA, Nitte University, Mangalore; 4 Department of Physics, Mangalore University, Mangalore
Ionizing radiation causes damage to living tissues through a series of molecular events, such as photoelectric, Compton and Auger effects, depending on the radiation energy. Radiation modifiers/protectors are the agents that when present prior to or shortly after radiation exposure alter the response of normal tissues to irradiation. For radioprotection, the factors like stimulation of stem cell proliferation, free radical scavenging, antioxidant, immunostimulation and DNA repair are essentially considered. Many literatures support the fact that cytokines and growth factors are Radiation Mitigators when used near the time of radiation. Kinetin is a well known cytokine with various therapeutic properties like anti-agening, anticancer. So present study was carried out to check the potentiality of the same in reducing electron beam radiation induced oxidative stress in mice model. The in-vivo studies were conducted to evaluate the levels of malondialdehyde and superoxide dismutase activity were estimated spectrophotometically. From the results obtained, both pre and post-treatment groups showed a trend of increase in MDA level and decrease in the SOD enzyme levels were observed in radiation control group when compared with control group. But, a noticeable trend of decrease in the level of MDA and increased SOD activity was observed in the treatment groups which indicate the decrease in lipid peroxidation was observed in treatment groups.
Abstract ID 0095
Magnetic Nanoparticles in Combination with Gamma Radiation Induce G2-M Arrest and Mitotic Catastrophe Mediated Cell Death in Mouse Fibrosarcoma Cell Line
Neena G. Shetake , Amit Kumar and Badri N. Pandey
Radiation Biology and Health Sciences Division, Mumbai 400085
In the present study, we have evaluated the cancer cell killing efficacy of oleic acid functionalized iron oxide magnetic nanoparticles (MN-OA) in combination with 2 Gy of gamma radiation and studied the underlying mechanism of cancer cell death. WEHI-164 cells treated with MN-OA + 2Gy showed a significant decrease in the clonogenic cell survival (9.4% ± 1.9%) as compared to untreated control (100%) or only 2 Gy (54.1 ± 2.2 %) or only MN-OA treatments (60.7 ± 3.1%), respectively. Further, cell cycle analysis showed that as compared to only MN-OA or 2 Gy, combination treatment induces significant G2-M arrest after 48 h of treatment. Although, combination treatment did not show a significant change in the % apoptotic cells at early time points (viz., 24 and 72 h), a significant increase in the % apoptotic cells was observed at later time points viz., 96 and 144 h. The delayed cell death indicates role of alternative cell death mechanism(s) like mitotic catastrophe in MN-OA induced radio-sensitization. To further confirm this, cells were stained with DAPI and alpha-tubulin antibody, to determine the number of polyploid cells and cells having multiple centrosomes, respectively, by fluorescence microscopy. After 96 h of treatment, a significant increase in the number of polyploid cells (42.25 ± 3.30) was observed in WEHI-164 cells treated with MN-OA+2 Gy as compared to 2 Gy (23.75 ± 3.09) or MN-OA (10.75 ± 0.5) treatments or untreated control (1.5 ± 0.5). In addition, WEHI-164 cells treated with MN-OA+2Gy showed presence of multiple centrosomes. These results indicate that MN-OA induced radio-sensitization of WEHI-164 cells is mediated via induction of G2-M arrest and mitotic catastrophe.
Abstract ID 0096
Determinaiton of Attenuation Properties of Saccharides Using Photon Energies
Bibifatima M. Ladhaf 1 , Prashant S. Kore 2 , Pravina P. Pawar 3
1, 2, 3 Nuclear Physics Research Laboratory, Department of Physics, Dr.Babasaheb Ambedkar Marathwada University, Aurangabad:431004. India.
The mass attenuation coefficients (mm ) for saccharides (Erythrose, Arabinose and Palatinose) has been measured using gamma ray transmission method in narrow beam good geometry set-up. Radioactive sources Co 57 , Ba 133 , Na 22 , Cs 137 , Mn 54 and Co 60 with energies in the range 122-1330 keV has been used. NaI(Tl) scintillation detection system having resolution of 8.2% at 662 keV from the decay of Cs 137 source has been used for detection of photons. The attenuation coefficient data were then used to obtain the total attenuation cross-section (σtot), mass-energy absorption coefficients (μen/ρ) and Kerma relative to air (K) of compounds. Theoretical values of attenuation parameters for the samples were obtained from WinXCOM programme. Experimentally calculated values show good agreement with theoretical values. The estimated errors are between 1 to 2%. Obtained data are found to be useful in medical field.
Abstract ID 0099
Effect of Glucose Capped Gold Nanoparticles in the Human Blood Lymphocytes using Alkaline Comet Assay
Saritha Suvarna and Narayana Yerol
Department of studies in Physics, Mangalore University, Mangalagangotri-574 199
Gold nanoparticles are playing important role in various biomedical applications in diagnostic, therapeutic and early detection of cancer cells due to their ability to bind with cancer cells. To ensure their safe use in various possible biomedical applications, it is essential to examine the DNA damage of glucose capped gold nanoparticls in lymphocytes. In the present study, glucose capped gold nanoparticles are synthesized by chemical route and Characterization was done by using UV-SPR, FTIR and SEM analysis. Glucose capped gold nanoparticles are treated with lymphocytes to check the DNA damage using Single-cell gel electrophoresis (comet assay), which provides a very sensitive method for detecting strand breaks and repair kinetics in single cells. Human biomonitoring studies using the Comet assay provide an efficient tool for measuring human exposure to genotoxicants, thus helping in risk assessment and hazard identification. Blood lymphocytes are treated with different concentrations, ranging from 10 µM to 90 µM, of glucose capped gold nanoparticles. Electrophoresis was performed at field strength of 0.74 V/cm for 23 min at 4°C. The DNA damages were quantified by the Olive tail moment. A comparative study over the sensitivity of different comet parameters such as tail length, tail moment and tail DNA has also been made. Studies showed that 10 µM to 30 µM concentration range of Glucose capped gold nanoparticles having no DNA damage and 40 µM -90 µM OTM values increases to 20%. It shows that 10 µM to 30 µM concentration of Glu-AuNPs for lymphocytes without any sign of DNA damage as evident from the OTM value.
Abstract ID 0100
Generation of Calibration Curve for Linear Energy Transfer Spectrometry Using CR-39 Track Detector
G.S. Sahoo 1 , S.P. Tripathy 1,4 , S. Paul 1 , Pankaj Kumar 2 , S.D. Sharma 3,4 , T. Bandyopadhyay 1,4 and D.K. Avasthi 2
1 Health Physics Division, Bhabha Atomic Research Centre, Mumbai, India - 400 085; 2 Inter University Accelerator Centre, New Delhi, India - 110 067;
3 Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, India - 400 085; 4 Homi Bhabha National Institute, Anushaktinagar, Mumbai, India - 400 094
CR-39 is a useful passive detector which can be employed for neutron spectrometry and dosimetry. In addition ,it can also be used for the procedures of microdosimetry by generating the linear energy transfer (LET) spectra. The calibration curve used for LET spectrometry was generated with a different etching procedure than the standard methodology used for neutron dosimetry. Therefore, in this work, a new calibration curve is generated using the standard etching procedure. The values of LET in water from 60 to 799 keV/μm were obtained from SRIM calculation using different energies of Li, C, O and F ions. CR-39 track detectors were then irradiated to 30 and 45 MeV of Li ions, 50 and 80 MeV of C ions, 50, 60 and 80 MeV of O ions and 60 and 70 MeV of F ions. The latent tracks were then developed using chemical etching (6.25 N NaOH, 70 0C, 6h). A thickness of 16 μm was removed from both sides of the detector after performing the etching. From the major and minor radii of tracks the V values (ratio of track etch rate to bulk etch rate) were obtained. The track diameter as well as the track area was found to be increasing with the LET values. The V values increased with the LET values and were fitted with the suitable relation. The fitting parameters and empirical relation was generated to correlate the LET values from V values which will be useful for generating the LET spectrum with standard etching procedure.
Abstract ID 0102
Nuclear Factor Erythroid 2-Related Factor 2 Inducers Increase the Radioresistance In Hematopoietic Cells By Up-Regulating Antioxidant Defence Responsive Genes
Dhananjay Kumar Sah 1, 2 Yogesh Rai 1 , Neeraj kumari 1 , Ankit Chauhan 1 , Madan Mohan Chaturvedi 2 Anant Narayan Bhatt 1
1 Institute of Nuclear Medicine and Allied Sciences, DRDO, Delhi. 2 Department of Zoology, University of Delhi, Delhi.
Exposure to Ionizing radiations (IR) is of great concern for all living beings either if they exposed during work or treatment. IR induced deaths are direct or mediated through various molecular mechanism. Living cells already have a defense system, which is regulated through Antioxidant Response Element (ARE). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox sensitive transcription factor that plays a critical defensive role against oxidative and cytotoxic stress. Nrf2 is stabilized by SKI-II and ZnCl 2 . Increase in Nrf2 level in cells after 2 and 4 h of exposure to these agents was observed at 0.1 µM of SKI-II and 100 µM of ZnCl 2 2 hours prior treatment with these agents followed IR provides significant radioresistance in the various hematopoietic and other cell lines like Raw267.4THP-1, HeK, NIH3T3, IEC-6 and. Further, clonogeic assay in NIH3T3 cells suggests increased clonogenic potential in SKI-II and ZnCl2 treated cells when exposed to 4 Gy IR. In addition, several antioxidants defence responsive factors were analyzed. ZnCl 2 and SKI-II treatment significantly reduced the level of ROS (DCFDA), Superoxide generation (Mito SoXred), Significantly increased the mitochondrial membrane potential (TMRM), levels of GSH at 4, and 24 hours in treatment group compared to IR alone. These agents activate ARE defense.
Abstract ID 0103
Interkulin -6 0 Induced Cytoprotective Signalling Protects the Cells from Radiation Induced Cell Death
Neeraj Kumari 1 , 2 ,Yogesh Rai 1 , Dhananjay Sah 1 , Ankit Chauhan 1 , Asmita Das 2 , Anant Narayan Bhatt 1
1 Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Timarpur, Delhi - 110054; 2 Department of Biotechnology, Delhi Technological University, Delhi 110042
Many TLR agonists and LPS are shown to protect the cells from radiation induced injury by activating the NF-kB signaling in hematopoietic and gut cells. Therefore, we postulated that mild NF-kB induction before irradiation can be beneficial; as it creates pro-inflammatory conditions which prepare the cells to cope up with the more pronounced radiation induced inflammation. IL-6 is one of the known inflammatory molecules that have been a major obstacle in radiotherapy by inducing resistance to radiation induced oxidative stress. It also protects normal cells like cardiomyocytes from oxidative stress. Therefore, we checked the radioprotective potential of IL-6 in hematopoietic (Raw264.7, THP-1) and fibroblast cell (NIH3T3). We found a significant increase in cell survival after IL-6 (1 ng/ml) treatment 2hr prior to radiation exposure. Further to dissect the mechanism of IL-6 mediated radioprotection, we tested its effect on anti-oxidant defense status (by DCFH2-DA and Mitosox), mitochondrial status (by TMRM and JC-1), DNA damage repair (by γH2AX foci assay), apoptosis (by AnnexinV-PI staining), NF-kB activation (by Lac-Z reporter assay) and the expression of pro-survival proteins (by western blot) in radiation exposed cells. We found that IL-6 pre-treatment showed a significant reduction in radiation induced ROS levels along with increased mitochondrial membrane potential (MMP). Using γ-H2Ax foci assay, we found that IL-6 pretreatment facilitates the repair of DNA damage. Furthermore, we observed an increased expression of anti-apoptotic proteins from Bcl2 family (Bcl2, Bcl-xl) along with reduced apoptosis, and increased expression of survivin, cyclin D. In addition, we observed an increased NF-kB activation in IL-6 treated cells. As the metabolic switch towards glycolysis is also an important mechanism to cause radioresistance in cells. In our study we found a significant increase in glycolysis after IL-6 treatment. And this IL-6 mediated protection was abolished after using a potent glycolytic inhibitor (2-DG). In conclusion, our study suggests that IL-6 protects the cells from radiation induced cell death by inducing antioxidant defense system and pro-survival signaling.
Abstract ID 0104
modification of Biological Response by Zinc Oxide Nanoparticle in Presence of Ultraviolet Radiation
Vinod Jaiswal , Mahesh Samant, V L Mathe 1 and Prabhakar Dongre
Department of Biophysics, University of Mumbai, Vidyanagari, Santacruz (E), Mumbai 400098. 1 Department of Physics, Savitribai Phule Pune University Pune 411007;
We report here, absorption of ultraviolet radiation by zinc oxide (ZnO) nanoparticles and its effect on biological system. Thermal plasma method was used for the synthesis of zinc oxide nanoparticles and characterized by scanning electron microscope (SEM) and X-ray diffraction. The average size of the ZnO nanoparticles was found to be 25 nm. The Potassium ferrioxalate Actinometry experiment was performed to observe ZnO nanoparticles induced conversion of Ferric to Ferrous ion (Fe +3 → Fe +2). The conversion of ferric to ferrous ions was significantly reduced in the presence of ZnO nanoparticles. The amount of UV energy estimated in the presence of ZnO nanoparticles was 143.10 erg/s-cm 2 whereas in the absence it was found to be 165.86 erg/s-cm 2 . The dose reduction factor was found to be 0.80. Similarly, mitotic index was modified by ZnO in presence of UV. Thus, the finding suggests that the ZnO nanoparticles prevent the conversion of Ferric to ferrous which indicates UV radiation protection.
Abstract ID 0105
Mass Attenuation Coefficient, Mean Free Path Copmutation of Glass Sample Containing PbO and ZnO in the Energy Range 122 keV to 1408 keV
D.K. Gaikwad , R.R. Bhosle, B.M. Ladhaf, P.S. Kore and P.P. Pawar
Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, India (MS):431004
Study on the interaction of gamma ray photons with composite materials such as alloys, biological samples, rocks, soils, plastics and glasses are widely used in radiation shielding, radiation dosimetry, medical physics and radiation biology. Shielding of gamma radiation is important since use of radioisotopes is increasing in the field of industry, radiography and research. Glasses containing lead oxide and oxide semiconducting materials can effectively shield gamma photons and have good radiation sensing properties, respectively. In the present work, glass containing PbO and ZnO has been fabricated by conventional melt-quenching method. The mass attenuation coefficient, mean free path, attenuation cross sections of the prepared glass sample have been measured using Eu 152 , Hg 203 , Cr 51 , Ba 133 , Cs 137 , Mn 54 , Zn 65 ,Co 60 radioisotopes. Aforesaid sources emitted 122 keV, 279 keV, 320 keV, 356 keV, 662 keV, 840 keV, 1115 keV and 1170 keV, 1330 KeV and 1408 keV energy of photons well collimated in a narrow beam good geometry setup and detected by a NaI(Tl) scintillation detector with good energy resolution. Measured results have been compared with theoretical values taken from XCOM program based on mixture rule. The variations in the measured values of mass attenuation coefficient, mean free path and attenuation cross sections of glass system with energy have been discussed and depicted graphically. It has been observed that the fabricated glass system has good absorption capability of gamma photons. The chosen sample is a good shielding material for present energies and have potential applications in radiation dosimetry and sensing of gamma rays.
Abstract ID 0106
Mitochondria as a Putative Early Indicator for Ionizing Radiation Induced Cellular Damage: Implications of Altered Redox Status, DNA Damage and Autophagy
Shubhankar Das 1 , Manjunath B. Joshi 2 , Kapaettu Satyamoorthy 2 , and B. S. Satish Rao 1
1 Department of Radiation Biology and Toxicology, School of Life Sciences, 2 Department of Biotechnology, School of Life Sciences, Manipal University, Karnataka 576 104, India
The contemporary theory of Radiation Biology defines that cellular damage post-radiation exposure occur through DNA damage/repair and oxidative stress related signaling processes. Recent findings speculate the role of mitochondria in response to radiation exposure and its association with radiation-induced cellular injuries. Therefore, the present study aims at understanding ionizing radiation induced mitochondrial structure/functional changes and the associated cellular damage using normal human fibroblast cells as an experimental model. Cells were exposed to X-rays (at 1 Gy/min) and mitochondrial fission/mass were investigated using MiTotracker red/ nonyl-acridine orange dyes and expression of pDRP (Ser 616). Functional changes were measured by comparative measurement of cytosolic/ mitochondrial ROS release using DCFH 2 DA/MiToSOX dye, changes in mitochondrial membrane potential (MMP) using Rhodamine 123, OxPhos activity, ATP synthesis and DNA damage using long amplicon PCR. Results showed that exposure to X-rays led to elevated pDRP1 levels along with mitochondrial fragmentation, concomitantly increasing the mitochondrial mass. Elevated cytosolic/ mitochondrial ROS levels were correlated with loss of MMP and OxPhos activity thereby lowering ATP levels. Long amplicon PCR analysis showed time dependent increase in mtDNA damage when compared to nuclear DNA segment indicating deleterious nature of X-ray which may be considered as a key causative factor for mitochondrial dysfunction. Experiments to elucidate the role of autophagy and its association with mitochondrial fission upon exposure to X-rays is underway which may provide better insight into ionizing radiation induced mitochondrial dysfunction and the consequent cellular damage.
Acknowledgement: The financial support from ICMR (53/8/2013-BMS), Government of India, the research facilities availed at School of Life Sciences and the fellowship in the form of Structured Ph.D. program of Manipal University is gratefully acknowledged.
Abstract ID 0107
Synergistic Immunomodulatory Effect of 2-Deoxy D Glucose and Chitosan on Irradiated Human Lymphocytes and LN-18 Cells
Shama Rao 1 , Sukanya Shetty 2 , Suchetha Kumari N 2 , Madhu L N 3 , Yogish Somayaji 1
1 Central Research Laboratory, K.S. Hegde Medical Academy, Deralakatte, Mangaluru, Karnataka; 2 Department of Biochemistry, K.S.Hegde Medical Academy, Nitte University, Mangaluru, Karnataka; 3 P.G Department of Biochemistry, St. Aloysius College, Mangaluru, Karnataka.
Radiotherapy is frequently used to obtain local or regional control of malignancies either alone or in combination with other modalities such as chemotherapy or surgery. Inflammation is the response of tissue or cell injury. Inflammation is mainly mediated by lymphoid cells, inflammatory cells and hematopoietic cells. This analysed the modulatory effect of IL-6, TNF-Alpha, IL-2 in irradiated human lymphocytes and LN-18 cells. Then cells were pre and post treated with 2-Deoxy D-glucose and Chitosan. Method used for the estimation of interleukins was Sandwich ELISA. IL-6 and IL-2 level was significantly increased (<0.05) in cells exposed to Electron Beam Radiation (EBR). TNF-α level was reduced in both the cells after exposing to EBR. IL-6 and IL-2 level was increased in Lymphocytes pre-treated with Chitosan. But increased secretion was noticed in cells pre-treated with 2DG. Synergistically level was decreased. In LN-18 cells IL-6 and TNF-α level found to be reduced in cells exposed to EBR. After treatment with 2DG and Chitosan these two interleukins level was increased significantly. IL-2 level was reduced in radiation control cells but after treatment with compounds IL-2 level was increased but was not significant. IL-2, TNF- α and IL-6 act as pro inflammatory marker. The level of IL-2 and IL-6 was increased after radiation exposure. In lymphocytes, after treatment with chitosan, level was decreased, which indicates the anti-inflammatory action of Chitosan. In LN-18 cells IL-6 and TNF- α level increased after treatment with 2DG and Chitosan.
Abstract ID 108
Understanding and Prediction of Normal Tissue Toxicity in Breast Cancer Patients by Cellular and Molecular Analysis
Kamalesh Dattaram Mumbrekar 1 , Hassan Venkatesh Goutham 1 , Donald Jerard Fernandes 2 , Krishna Sharan 2 , Bejadi Manjunath Vadhiraja 3 , Bola Sadashiva Satish Rao 1
1 Department of Radiation Biology and Toxicology, School of Life Sciences, Manipal University, Manipal; 2 Department of Radiotherapy and Oncology, Shiridi SaiBaba Cancer Hospital and Research Centre, Manipal University, Manipal; 3 Department of radiation oncology, Manipal Hospitals, Bangalore, India
Radiotherapy (RT) induced normal tissue toxicity is one of the major limitations for achieving the desired therapeutic effect and has negative impact on quality of life. Clinical experience indicated that about 10% of patients who underwent RT developed severe adverse reactions in normal tissues. The present investigation aimed to assess the usefulness of gamma H2AX foci (for DSB analysis) in deciphering the cellular radioresponse of healthy individuals (n=100) and to assess the role of genetic variants on the observed variation. The investigation envisaged the predictive potential of gamma H2AX foci analysis and the influence of 39 selected genetic variants from genes involved in DNA damage recognition-repair, oxidative stress response, xenobiotics metabolism and cell cycle on their risk for acute normal tissue adverse reactions in breast cancer patients (n = 132) undergoing curative RT. Our results suggested that the gamma H2AX assay and genetic variant in CD44 (rs8193) may have its potential to be developed into a clinically useful predictive biomarker. Further, XRCC6 rs2267437 (P = 0.0340) and LIG4 rs1805388 (P = 0.0250) in understanding cellular radiosensitivity in healthy individuals. The insight gained from this extensive investigation may be helpful for the detection of radiosensitive individuals in a healthy population and may have its clinical implications in the prediction on the risk of developing adverse skin reactions in those patients undergoing radiotherapy.
Abstract ID 0109
Radiation Enhances Shelf Life of Nendra Bananas Without Changing the Lectin Content of Raw and Steamed Nendra Banana
Neil Renault Coelho 1 , Shashikiran Nivas 1 and LD'Souza
1 Laboratory of Applied Biology, St Aloysius College, Mangalore - 575003
Nendra is a popular banana variety used in Kerala and coastal Karnataka as fruit and also for medicinal purposes. Studies show that banlec, a jacalin related lectin found in banana fruit pulp, has the potential to inhibit HIV replication according to Swann. However, these bananas get spoilt easily because of the humid tropical weather conditions of these regions and cannot be stored for longer durations. Radiation has been found to increase the shelf life of many fruits. However, the question is whether it will interfere with the nutrition or medical properties of these fruits. Our study shows that the shelf life of bananas is increased with low doses of radiation (300 Gy, 400 Gy, 500Gy). However, there is no decrease in the lectin content. This improves the keeping quality of nendra bananas without affecting their lectin content. Hence, radiation can be used safely for the bananas distributed to HIV children. The present study was also to compare the lectin content of raw and steamed Nendra bananas with the gamma irradiated bananas. The pulp from raw and steamed Nendra bananas was subjected to various levels of gamma radiation (100 to 500 Gy). Lectin from banana fruits was extracted using the protein precipitation method. The quantification of lectin content was done using chromatography techniques and SDS according to Laemmli. The effect of radiation on the lectin content was noted at regular intervals of time. The present comparative study will be helpful to study the possibilities of enhancing the lectin content and for supplying the right condition (raw/steamed) of Nendra bananas to HIV positive children as a part of their therapy.
Abstract ID 0111
Radioimmunoassay of Triiodothyronine in Rat Serum
Jayula Sarnaik , ShripriyaPurohit, Vijay Kadwad, Shalaka Paradkar, Rani Gnanasekar, Satbir Singh Sachdev
Radiopharmaceuticals Programme, Board of Radiation and Isotope Technology (BRIT), BRIT Vashi Complex, Navi Mumbai-400703, Maharashtra, India
Rat models are extensively used for evaluating therapeutic effects of new drugs and carcinogenicity testing which includes measurement of hormone levels in rat serum, due to the similarity between rat and human thyroid physiology. We describe radioimmunoassay (RIA) procedure for the estimation of triiodothyronine (T3) in rat serum. RIA procedure was designed, developed and validated using sheep anti-T3 antibody, radioiodinated T3 using I-125 (specific activity: 3000 µCi/µg). Rat serum depleted of T3 by charcoal treatment was used to prepare T3 standards. The assay employs 100 µL of standards/samples with an incubation of 45 min at 37 0 C. The method was validated for standard assay parameters. The sensitivity of assay was observed to be 0.12 ± 0.01 ng/ml. The recovery of spiked samples varied from 89 to 111%. The samples for linearity study measured with 2-8 fold dilutions varied from 86% to 110%, conﬁrming parallelism between the standard and serum samples. The inter-assay and intra-assay variations were found to be <10%. The in-house developed assay provides a reliable tool for the estimation of rat T3 and has the potential to replace expensive imported rat RIA T3 kits. In conjunction with rat T4 RIA procedure developed at BRIT, this assay can be used to assess the thyroid function in rats.
Abstract ID 0112
Ellagic Acid Mediated Enhanced Apoptotic Sensitivity Via G1 Cell Cycle Arrest and γ-H2AX Foci Formation in HeLa Cells
VR. Ahire 1 , A.Kumar 2 , BN Pandey 2 , KP Mishra 3 , GR Kulkarni 1
1 School of Basic Medical Science; University of Pune.Ganeshkhind. Pune; 2 RBandHSD, Bhabha Atomic Research Center, Trombay, Mumbai. India; 3 Foundation for Education and Research, India and BM International Research Centre, Mumbai, India
Herbal polyphenols have gained significance because of their increasing promise in prevention and treatment of cancer. Therefore, development of a dietary compound as an effective radiosensitizer and a radioprotector is highly warranted for cervical cancer patients undergoing therapy. This study describes the cytotoxic effects of the flavonoid, ellagic acid (EA) when administered either alone or in combination with gamma radiation on cervical cancer HeLa cells in vitro. Apoptotic index and proliferation were measured by using trypan blue assay. Reproductive cell death was analyzed by clonogenic assay. Propidium iodide staining for flow cytometry was performed to analyze cell cycle modulation. Nuclear and mitochondrial changes were studied with specific dyes. DNA repair kinetics was analyzed by immunofluorescence assay. Evaluation and comparison of EA effects were performed with other clinically used breast cancer drugs. When tumor cells were exposed to 2 and 4 Gy of irradiation in presence of EA (10 μM), it yielded a synergistic cytotoxic effect on cervical cancer cells whereas in NIH3T3 cells, it reversed the injury caused by irradiation and abetted in the regaining of normal healthy cells. At 24 h, ~ 25 foci/cell and 2.6 fold decrease in the mitochondrial membrane potential was observed. Upto 40% cells were arrested in the G1 phase and 20-36% cells exhibited apoptosis. Our results demonstrate the role of increased apoptosis and cell cycle modulation in the mechanism of EA mediated radiosensitization of cervical cancer cells, thus advocating EA as an adjuvant for preclinical trials in cancer chemo- radiotherapy.
Abstract ID 0114
Biochemical Interaction of Thorium and Uranium with Hemoglobin: Effect on Oxygen-HB Binding and Its Correlation with Survival of Chironomus Larvae
Manjoor Ali 1 , Amit Kumar 1 , Pallavi Gaikwad 2 , Bimalendu B. Nath 2 and Badri N. Pandey 1
1 Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-85, 2 Department of Zoology, University of Pune-07, India,
Thorium-232 (Th) and Uranium-238 (U) are naturally-available actinides and have been used for various civil and nuclear applications. However, the biochemical basis of Th and U complexation has not been thoroughly investigated, which have relevance for i) understanding their radiological and chemical effects and ii) the development of efficient approaches for human health protection. The most abundant metal in blood is iron (Fe) in the form of hemoglobin (Hb). Since charge-to-size ratio of Th is similar to Fe, present investigation was carried out to study the effects of Th/other metal ions [uranium: U (VI), lanthanum: La(III), cerium: Ce(III) and (IV)] on the structure and function of Hb. Results showed that these metal ions, except Ce(IV) interacted with carbonyl and amide groups of Hb, which resulted in the loss of its alpha-helix conformation. However, beyond 75 µM, these ions affected heme moiety. Metal-heme interaction was found to affect oxygen-binding of Hb, which seems to be governed by their closeness with the charge-to-ionic-radius ratio of iron(III). Consistently, Ce(IV) being closest to iron(III), exhibited a greater effect on heme. Binding affinity of Th(IV) was higher than that of U(VI). Experiments using aquatic midge Chironomus (possessing human homologous Hb) and human blood, further validated metal-Hb interaction and associated toxicity. Thus, present study provides a biochemical basis to understand the actinide/lanthanide-induced interference in heme, which may have significant implications for the medical and environmental management of lanthanides/actinides toxicity.
Abstract ID 0116
Assessment of Radiation Safety Awareness and Attitude toward Biological Effect of Radiation for Employees in Nuclear Workplace
U. Youngchuay , S. Jetawattana, V.Toeypho, J. Eso
Thailand Institute of Nuclear Technology (Public Organization)
Thailand Institute of Nuclear Technology (TINT) is a state-owned research and service nuclear technology organization in Thailand. The executive management strongly supports the radiation protection program for workers. In this study, we developed radiation safety awareness and attitude questionnaire to verify the radiation protection program at TINT. Eighty five volunteers, composed of two groups: radiation and non-radiation workers were selected. The questionnaire contains demographics, radiation working conditions, awareness on radiation safety and attitude toward biological health effect of radiation. Level of awareness on radiation safety was found significantly higher in radiation worker group (p < 0.05). The non-radiation workers with bachelor degree appear to have a more favorable attitude toward biological effects of radiation than those with lower degree (p < 0.05). In contrast, education degrees did not have any influence on attitudes or awareness of radiation effects in a group of radiation workers. In total, 45 exposed workers were reviewed for their dose records accounting up to 15 years of employment and the average cumulative effective dose of 10.7 ± 0.10 mSv was observed. This study demonstrated a potential relevance of data pertaining to the interaction of awareness in radiation biology and their attitude towards radiation hazards. The obtained information is useful in ascertaining the effectiveness of the ongoing radiation safety program and will be further used to determine the relationships between the radiation effective dose and cytogenetic approach in these groups of workers.
Abstract ID 0117
Radio/Photo Sensitization of Human Oral Cancer Cells through Activation of Iodo-Chlorin P6 Copper Complex with X-Ray Radiation
P. Sarbadhikary 1 , A. Dube 1, 2 , V.P. Dhamgaye 3 , P. K. Gupta 1, 2
1 Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore 452013, India. 2 Laser Biomedical Application and Instrumentation Division, Raja Ramanna Centre for Advanced Technology, Indore 452013, India. 3 Materials Research Lab, Indus Synchrotrons Utilization Division Raja Ramanna Centre for Advanced Technology, Indore 452013, India
Photodynamic therapy is a very attractive modality for the treatment of cancer because of its very high tumor selectivity. However, it suffers from the drawback that because of low penetration depth of light only superficial tumors can be treated. One approach to address this limitation is to conjugate the photosensitizer with high Z element and use the x-ray to activate the photosensitizer. For this purpose, we have synthesized a copper iodide complex of Chlorin p6 (ICp6Cu) and evaluated its efficacy for x-ray radiation induced radio/photo sensitization of cancer cells. Human oral cancer cells (Nt8e and 4451) were incubated with ICp6Cu for 3 hrs and irradiated with polychromatic x-ray beam (8-12 keV) from Indus-2 synchrotron radiation source. Cell viability was determined by MTT assay and Hoechst/ PI fluorescence staining. As compared to free Cp6, the cellular uptake of ICp6Cu was observed to be ~ 3 times higher. Results obtained on irradiation of cells with x-rays both without and with ICp6Cu showed a dose dependent increase in cytotoxicity and in cells treated with ICp6Cu, the magnitude of cytotoxicity was significantly higher by ~25% and ~40% for Nt8e and 4451, respectively. By putting layers of tissue phantom (gelatin-agarose) of increasing thickness (up to ~ 20 mm) depth dependent x-ray induced cytotoxicity has been investigated and the results showed significant toxicity even up to this depth. Results suggest that ICp6Cu enhanced the sensitivity of cells to x-ray radiation and would be useful for deep tumor treatment.
Abstract ID 0118
Radiation Tolerance Decreases During Early Pupal Stage of Fruit Fly Drosophila melanogaster
Jagdish G. Paithankar 1, 2 , Rajshekhar K. Patil 1, 2 and H. M. Somshekarappa 21
Department of Applied Zoology, Mangalore University, Mangalagangotri, Mangalore 574 199, Karnataka; 2 Centre for Application of Radioisotopes and Radiation Technology (CARRT), Mangalore University, Mangalagangotri, Mangalore 574 199, Karnataka.
Radiation energy is known to have beneficial as well as harmful effects on living organisms, compared to mammals the insects are found to have high radiation tolerance. It is interesting to know the underlying mechanisms. Drosophila melanogaster was exposed to varying doses of gamma radiation during different developmental stages. Doses from 0 Gy to 2200 Gy with an increment of 100 Gy, till 100% mortality was observed, with the dose rate of 12 Gy/min to 25 Gy/min was given using Gamma Chamber 5000 and Low Dose blood irradiator 2000, which has 60 Co source (BRIT, Mumbai). Post-irradiation studies were done depending on the stage of development, eggs were observed for hatching, pupae for eclosion, larvae and adults observed for mortality respectively. Following gamma irradiation, 100% mortality was recorded at 1000 Gy for eggs, 2200 Gy for third instar larvae, 130 Gy for early pupae, 1500 Gy for late pupae and adults. LD 50 was recorded around 450 Gy for egg, 1600 Gy for third instar larva, 50 Gy for early pupa, more than 900 Gy for late pupa, 1228 Gy for adult for male and 1250 Gy for adult females. Thus, early pupae was recorded as the most sensitive stage and third instar larva was reported as most tolerant stage. With the chromosome numbers and biochemical parameters as total antioxidant capacity being nearly constant, it is suggested that high rate of cell division during the early pupa renders the stage sensitive to radiation.
Abstract ID 0119
Proteomic Responses of Human Peripheral Blood Mononuclear Cells from Individuals Residing in High Level Natural Radiation Areas of Kerala
Nishad S and Anu Ghosh
Radiation Signaling Group, Radiation Signaling and Cancer Biology Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Mumbai-400085.
Over the years, biological and cellular effects of high doses of ionizing radiation (IR) on humans have been convincingly established. However, effects of low doses of IR on humans continue to be debated. The population living in the monazite bearing coastal belt of Kerala (with annual background radiation levels of ≤1 mGy to ≥45 mGy) offer a distinct potential to understand effects of chronic low dose directly on humans. Since proteins are considered real effector molecules in the cell, changes in the proteome can be effectively used to understand cellular responses to low dose radiation. This study investigated differential proteomic changes in human peripheral blood mononuclear cells (PBMCs) from seven male individuals from High Level Natural Radiation Areas (HLNRA) as compared to seven male individuals from the adjoining Normal Level Natural Radiation Areas (NLNRA) of Kerala. Comparative proteomic analysis using two dimensional analysis coupled with mass spectrometry (MALDI-TOF MS) identified five proteins that were significantly (fold change ±1.5, p≤0.05) altered in individuals from HLNRA as compared to NLNRA: 78KDa Glucose regulated protein (GRP78), beta/gamma actin (cytoskeletal protein), lactate dehydrogenase (carbohydrate metabolism) and fibrinogen beta and gamma (extracellular proteins). Higher expression of GRP78, which is involved in unfolded protein response, in HLNRA individuals, indicates a possible upregulation of pro-survival pathways with chronic radiation.
Abstract ID 0121
Investigation of Percentage Depth Dose Curves in Inhomogeneous Medium for Electron Therapy: A Simulation Approach Study
A. S. Jagtap 1 , B.J. Patil2 , Gauri Kulkarni 1 , S.S. Dahiwale 1 , S.T. Chavan 3 , S.N. Pethe 3 , V.N. Bhoraskar 1 , S.D. Dhole 1
1 School of Basic Medical Sciences, Department of Physics, Savitribai Phule Pune University, Pune -7, 2 Abasaheb Garware College, Karve Road, Pune - 411004, 3 SAMEER, IIT Powai Campus, Mumbai 400076
Electron beam therapy is widely being used alone or along with photon beam for radiotherapy practices. It is also being used very often for skin cancers treatment as well as a boost treatment for different tumor sites after photon therapy. Electron beam dose distribution can be significantly altered in the presence of tissue in homogeneity such as bone, lung, and air cavities. It is difficult to determine dose distribution within or around small inhomogeneity because of enhanced electron scattering effects, therefore, accurate knowledge of dose distribution in homogeneous and inhomogeneous medium is very important for the delivery of accurate dose and treatment. In present work, EGSnrc Monte Carlo code has been used for the calculation of percentage depth dose (PDD) in water medium and effect of tissue in homogeneity (Bone) on PDD. Electron beam of energies 4, 8, 12, 16 and 20 MeV have been used for the simulation purpose. Bone of different thicknesses has been inserted before the build-up region of the PDD curve and its effect on the dose distribution has been studied. It has been observed that for each electron energy, the values of R90, R50, Rp have been decreased linearly with the bone thickness. Also, it has been found that below the depth of inhomogeneity, PDD has increased by 10% for 0.8 cm of bone at 12 MeV. It is concluded that because of inhomogeneity, PDD beyond inhomogeneity increases and after Dmax it decreases. This data could be useful for the clinicians to define dose prescription point during electron beam therapy and can achieve the perfection of treatment.
Abstract ID 0124
Control of the Dose Distribution in Charged Particle Therapy
University of Torino and Istituto Nazionale di Fisica Nucleare, Via Pietro Giuria 1, 10125 Torino, Italy
The use of ions in radiation therapy aims at improving the selectivity of the irradiation thanks to a favorable depth-dose profile and, in case of heavy ions, to their enhanced radiobiological effect. The treatment modality employing actively scanned pencil beams provides highly conformal dose distributions but could be sensitive to uncertainties in the dose calculation, delivery and measurement. In particular, the treatment planning has to evaluate the biological effect of a complex radiation field, using detailed and fine tuned physical and radiobiological models and taking into account different particles and fragments with mixed LET. During the treatment, the delivery of the beam has to be controlled in real time and monitored with high accuracy, including any effect due, for example, to patient position and motion. The talk will give an overview of recent techniques and trends for the delivery, measurement and verification of the dose distribution in charged particle therapy with scanned ion beams, focusing in particular on the monitoring of the deviation from the planned dose due to patient motion and on the measurement of the beam flux with high intensity pulsed beams.
Abstract ID 0126
Single Isotopes for Combined Positron Emission Tomography/Single Photon Emission Computed Tomography Imaging
C. Rangacharyulu 1 , R. Tannous 1 , C.K. Roh 1 , J.K. Kim 2 , J.H.Park 2 and S.D. Yang 2
1 Department of Physics, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5E2, 2 Radiation Instrumentation Division, Korea Atomic Energy Research Institute, 580-185, Jeongup, Republic of Korea
In light of the scattering and absorption artifacts of nuclear medical imaging by PET and SPECT, we identified several candidate isotopes which afford to combine both techniques into one single isotope based imaging. The data of time coincidence measurements of annihilation quanta with the associated gamma ray provide for 3-D imaging by decay vertex reconstruction. Additionally, the data for conventional PET and SPECT imaging are simultaneously obtained without additional radiation dose to the patient. This method will vastly improve the image contrast and it provides multiple views based on software cuts of the images to the radiologist, enabling him/her to critically evaluate them for diagnosis. The candidate isotopes must satisfy several criteria such as feasibility and economy of production channels, dual energy and photon intensity measures and biological compatibilities. From a detailed study of nuclear database for the decay properties of positron emitters, we have currently short-listed 43-Sc, 73-Se, 123-Xe, 85-Y, 77-Kr and 75-Br as prospective candidates, all of which can be produced at proton cyclotrons of 20-60 MeV energies. Now, we are critically evaluating interfering radioactivities, if any, and working on optimizing the proton beam energies, target material compositions and radiochemical techniques for the product developments. This talk will summarize our progress to date and our plans for future.
Abstract ID 0128
Protective Effect of Asparagus racemosus Root Extract against Lethal Total - Body Electron Beam Radiation Induced Damage in Swiss Albino Mice
Sharmila K.P 1 , Satheesh Kumar Bhandary B 2 , Suchetha Kumari.N 3 ,Vadish S. Bhat 4 ,Ronald Fernandes 5 ,Jayaram Shetty 6 , Alex John Peter 7 , Jerish M. Jose 8
1 Central Research Laboratory, 2,4 Department of ENT, 3 Department of Biochemistry, 5 Department of Pharmaceutical Chemistry, 6, 7,8 Department of Oncology, 1, 2, 3, 4, 6,7,8 K. S.Hegde Medical Academy, Nitte University, Mangalore, Karnataka., 5 NGSM Institute of Pharma Sciences, Nitte University, Paneer, Deralakatte, Mangalore, Karnataka.
Radiation toxicity is a kind of physical stress that humans risk in events such as nuclear pollution, radiation therapy for cancer, and space flights. Although radiotherapy is effective in killing tumor cells, Reactive Oxygen Species produced during the process threaten the integrity and survival of surrounding normal cells. Several compounds have been reported to offer the potential for radiation protection, but most of them are not suitable for clinical application due to toxicity and poor specificity. This warrants the development of suitable radioprotective agents with minimum toxicity that can be used under occupational as well as clinical conditions. Asparagus racemosus also known by the name Shatavari is a spinous under shrub, belonging to family Asparagaceae. It is known to prevent ageing, increase longevity and impart immunity. To investigate the protective effect of Asparagus Racemosus Root ethanolic extract (ARE) in Swiss albino mice against acute lethal total - body Electron beam irradiation. Swiss Albino mice were used for the assessment of radiation induced sickness and 30 day survival analysis. Survival studies were determined using the Kaplan-Meier survival curves. The maximum survival was observed in the experimental mice pretreated with 200 mg/kg.b.wt. of ARE which also reduced the radiation sickness characteristics. This dose was considered as an optimal dose for radioprotection. Treatment of mice with ARE before irradiation delayed the onset of mortality as compared with the untreated irradiated controls. Present findings demonstrate the potential of ARE in mitigating radiation-induced mortality, which may be attributed to its Free radical scavenging and increased antioxidant potential.
Abstract ID 0129
Antigenotoxic Potential of Asparagus racemosus Root Extract against Electron Beam Radiation Induced Micronuclei Formation in Swiss Albino Mice
Satheesh Kumar Bhandary B 1 , Sharmila K.P 2 , Suchetha Kumari.N 3 ,Vadish S. Bhat 4 , Ronald Fernandes 5 , Jayaram Shetty 6 , Alex John Peter 7 , Jerish M. Jose 8
1,4 Department of ENT, 2 Central Research Laboratory, 3 Department of Biochemistry, 5 Department of Pharmaceutical Chemistry, 6, 7,8 Department of Oncology, 1, 2, 3, 4, 6,7,8 K.S.Hegde Medical Academy, Nitte University, Mangalore, Karnataka., 5 NGSM Institute of Pharma Sciences, Nitte University, Paneer, Deralakatte, Mangalore, Karnataka.
Radiation is one of the most important environmental factors because of its hazardous health effects, which include oxidative stress, hematopoietic system dysfunction and genetic mutations. Reactive Oxygen Species generated during radiotherapy causes chemical modification of biomolecules, giving rise to genomic instability leading to mutagenesis, carcinogenesis and cell death. In recent years, the development of novel and effective agents to combat radiation damages using non-toxic radioprotectors is of considerable interest particularly in radio diagnostics and therapy. Asparagus racemosus also known by the name Shatavari is a spinous under shrub, belonging to family Asparagaceae. It is known to prevent ageing, increase longevity and impart immunity. To evaluate the antigenotoxic potential of Asparagus Racemosus Root ethanolic extract (ARE) against electron beam radiation induced micronuclei formation in Swiss albino mice. Micronucleus assay was performed in the bone marrow of Swiss albino mice according to the method of Hosseinimehr et al., 2003. The experimental animals were orally administered 200 mg/kg body weight of ARE once daily for 15 consecutive days. At the end of experimental period, the animals were euthanized and the bone marrow was collected from the femur. Control (C), Radiation control (RC) and drug control (DC) group was also maintained. The number of radiation induced Micronucleated Polychromatic Erythrocytes (MnPCE) and Micronucleated Normochromatic Erythrocytes were decreased in the ARE treated mice which was statistically significant (p<0.05) compared to radiation control group. Present findings demonstrate the antigenotoxic potential of ARE against electron beam radiation induced micronuclei formation which may be attributed to scavenging of radiation-induced free radicals.
Abstract ID 0130
Radiotherapy Dosimetry Using Dosimetrically Characterized Commercial Optically Stimulated Luminescence Nanodot System
Gourav Jain , Ananth K., Arun Chougule, Suresh Kumar Akula
Department of Radiological Physics, SMS Medical College, Jaipur, India-302004
OSL has been used extensively for radiation beam dosimetry, radiation protection including in vivo measurements due to their simple readout process, multiple readout facility and dose reanalyzation. The OSL system used is a commercial InLight TM microStar reader system with Al 2 O 3 :C nanoDot TM , manufactured by Landauer. Bhabhatron-ll Telecobalt unit and Varian Clinac-iX linac are used for various measurements. OSL detectors were checked for reproducibility, accuracy, dose linearity, energy, dose rate and angular dependency. The OSL system was used to measure radiotherapy dosimetry parameters like PDD and OF. OSL nanoDot dose deviation is about -4.5% as compared with ionization chamber. The reproducibility of the detector is found to be within 3.44% standard deviation, with COV 0.035. There is no significant energy and field size dependence of Al 2 O 3 :C nanoDot. The detector response is linear upto 225 cGy with COL 0.05 and after that nonlinear response is observed. OSL response is almost independent of low angle of beam incidence when buildup is used but maximum deviation went upto 8% at higher angles of beam incidence. However, there is large variation observed at 90Ί and 270Ί gantry angles due to limitations of phantom and dosimeter geometry. The PDD and OF are measured using nanoDot and compared with ion chamber. The dosimetric characteristics of OSL system were studied and found that OSL response is energy and dose rate independent but a non linear calibration is required at higher doses. The stability of system and linear clinically relevant dose response relationship makes it a good dosimeter for in vivo dosimetry in radiotherapy for present and it can be developed further for relative radiotherapy dosimetry for future.
Abstract ID 0131
Scr7, an Inhibitor of NHEJ Abrogates Tumor Progression in Mice, and Can Reduce the Effective Dose of Radiotherapy
Sathees C. Raghavan
Department of Biochemistry, Indian Institute of Science, Bangalore, India
Repair of DNA double-strand breaks (DSBs) is critical for maintenance of genome integrity. Nonhomologous end-joining (NHEJ) is the predominant DSB repair pathway in higher eukaryotes. Therefore, inhibition of DSB repair can be used as a strategy to induce apoptosis in cancer cells. Previously, we had chemically synthesized and characterized a novel inhibitor of Ligase IV (SCR7), an enzyme critical for NHEJ. Using biochemical assays, we showed that addition of SCR7 to testicular extracts abolished joining by NHEJ. SCR7 interfered with the joining of compatible DSBs catalysed by purified Ligase IV. Electrophoretic mobility shift and circular dichroism studies suggest that SCR7 binds to Ligase IV and interferes with its interaction to DNA ends suggesting that SCR7 is a Ligase IV inhibitor. Further, using mice models, we find that SCR7 treatment inhibited progression of breast adenocarcinoma, but not haematopoeitic cancers, resulting in a significant increase in life span. Interestingly, SCR7 impedes tumor progression significantly, when coadministered with existing DSB inducing therapeutic modalities. More importantly, we show that when coadministered, SCR7 could reduce the effective dosage of g-radiation from 2 to 0.5 Gy, in cancers derived from breast cancer, colon cancer and B-ALL. Histopathological and immunofluorescence evaluation suggest that cytotoxicity induced is restricted to tumor. Further, encapsulation of SCR7 in micelles can improve its efficacy by ~4-fold. Thus, using biochemical and biophysical approaches, we show that SCR7 is a potent inhibitor of NHEJ, can be used as a chemotherapeutic agent and upon coadministration, can bring down the effective dose of radiotherapy.
Abstract ID 0132
Evaluation of Post-Radioprotective Potential of Methanolic Extract of Tragia involucrata on Cultured Human Lymphocytes Exposed to Gamma Radiation
Nivya MT 1 , Chandrashekhar G Joshi 1 , KP Rajashekhar 2 , Gopal M 3 , HM Somashekarappa 4 , Vijay R 1 , Ananda D 1 , Manjunath HM 1 , Suchetha Kumari N 5
1 Department of Biochemistry, Mangalore University, PG Centre, Chikka Aluvara, Kodagu-571232,Karnataka; 2 Department of Applied Zoology, Mangalore University, Mangalagangothri Mangalore-574199, Karnataka; 3 Department of Biochemistry, Davangere University, Tolahunse, Davangere, Karnataka; 4 CAART, Mangalore University, Mangalagangothri Mangalore-574199, Karnataka; 5 Department of Biochemistry, K.S.Hegde Medical Academy, Nitte University, Mangalore-571018, Karnataka
Medicinal plants with diverse bioactive components are explored due to their radioprotective property. A Euphorbiaceaean member, Tragia involucrata was found to have medicinal properties and has been used in the traditional and tribal medicine to treat various ailments. Present study was designed to evaluate the radioprotective effect of methanolic extract (ME) of T. involucrata on cultured human peripheral lymphocytes. Lymphocytes were isolated, irradiated with 3 Gy gamma radiation and treated with different concentrations of ME for 24 hours. Percentage of cell viability was determined using trypan blue dye exclusion method. DNA damage studies were done by comet and micronucleus assay. Treatment of lymphocytes with ME after irradiation had significantly reduced the damages in test group comparison with the control cells. There was a decrease in comet parameters such as percentage DNA in tail, olive tail moment and micronuclei formation compared to radiation control. Treatment of cells with 10 μg/ml of ME showed highest viability. Present study established for the first time the radioprotective potential of T.involucrata. Further in vivo studies will help in the development of novel radioprotective agent.
Abstract ID 0133
Role of G4 DNA in Differential Radio-Protection of the Genome
Supriya V. Vartak and Sathees C. Raghavan
Department of Biochemistry, Indian Institute of Science, Bangalore, India
Ionizing radiation affects the genome by causing DNA breaks, mutagenesis and genomic instability. IR-induced DNA strand breaks are believed to be distributed throughout the genome in a random manner, however, a clear understanding of the distribution pattern, or the factors governing the same, are yet to be deciphered. In order to address this, we employed various biochemical and biophysical assays to evaluate the sensitivity difference between the four DNA bases. Our results showed that single stranded DNA containing Poly(G) failed to show the standard cleavage pattern, unlike other three bases. We further explored this finding by employing oligomers mimicking various sequences of the human genome and found that it is the DNA structure, not the sequence, which resulted in protection against IR-induced cleavage. The most common, stable structure formed by G-rich sequences is the G-quadruplex, a non-B DNA structure functionally important for transcriptional regulation, telomere maintenance, etc. Our results showed that telomeric repeats are shielded from IR, when analyzed in a plasmid DNA context. Telomere FISH, along with gamma-H2AX signals showed minimal co-localization, suggesting intact telomeres. Importantly, real-time analysis of several independent regions of the genome demonstrated protected G4 forming regions, as compared to random ones. Thus, our study reports the role of non-B DNA structure during differential radioprotection of the genome.
Abstract ID 0135
Radioadaptive Response of Diallyl Disulphide in Electron Beam Radiated Swiss Albino Mice
Suchetha Kumari N 1* , Yogish Somayaji T 2
1 Professor, Dept. of Biochemistry, K S Hegde Medical Academy, Nitte University, 2 Dept. of Biochemistry, Central Research Laboratory, Nitte University.
Diallyl disulphide (DADS) is an organosulphur compound present in garlic which has been studied for its anticancer and antioxidant properties. In the present study, it was evaluated for its protective role in radiation adaptive doses. Mice were irradiated initially with 1Gy of priming dose and after 24 hours a challenge dose of 5 Gy was given. There was no adaptive response seen in the hematological parameters, as there was decrease in the haemoglobin, red blood cell and white blood cell count seen in irradiated groups with single sublethal dose and adaptive split dose groups. No change in the levels of catalase, glutathione peroxidase with slight increases in superoxide dismutase and glutathione (GSH) levels provide a circumstantial evidence of dose adaptation, but decrease in the total antioxidant capacity and increase in malondialdehyde indicate deteriorating antioxidant levels. But a distinct decrease in the olive tail moment of the group irradiated with adaptive split dose on comparison with single sublethal dose indicated an adaptive response in the DNA damage levels. The DADS pretreatment prior adaptive split dose irradiation showed an enhanced adaptive response to DNA damage when compared to its respective adaptive split dose radiation control group. Intra cellular non-protein sulphydryl groups are mainly involved in enhancing the membrane stability and antioxidant capacity and diallyl disulphide in the present study has shown enhanced GSH levels, total antioxidant capacity and reduced the malondialdehyde levels in sublethal and lower sublethal dose radiation groups. DADS has shown reduced DNA damage in adaptive split dose groups and also has contributed to the radio-adaptive response.
Abstract ID 0136
Radioprotective Efficacy of Carica papaya (l.) Leaf Extract in Electron Beam Irradiated Swiss Albino Mice
Yogish Somayaji T 1 , Suchetha Kumari N 2
1 Dept. of Biochemistry, Central Research Laboratory, Nitte University., 2 Professor, Dept. of Biochemistry, K S Hegde Medical Academy, Nitte University
Previous studies have shown that leaf extract of Carica papaya (Linn.) has antibacterial, antitumor, antioxidant, anti-sickling properties and has shown to increase the platelets in patients with dengue fever. In the present study, the radioprotective effects and radioadaptive response of Carica papaya (L.) was evaluated in mice irradiated with electron beam radiation. Radiation induced hematological suppression was seen at sublethal doses of 6 Gy irradiated groups. There was a decrease in hemoglobin, red blood cell, total white blood cell count and platelet counts in irradiated groups whereas papaya leaf extract enhanced platelet levels indicated thrombopoietic effect. A decrease in the total antioxidant capacity and catalase levels were seen in irradiated groups compared to the non-irradiated groups. Reduced levels of glutathione (GSH) and malondialdehyde (MDA) were seen in the irradiated groups indicating increased lipid peroxidation. Papaya leaf extract pretreatment, prior irradiation, increased the total antioxidant capacity, GSH levels and decreased the MDA levels. There was increased olive tail moment in irradiated group indicating radiation induced DNA damage. Similar effects were seen in the radiation studies at a lower sublethal dose of 1 Gy, where there was a decrease in the hematological parameters. Papaya leaf extract pretreatment group, prior irradiation, enhanced the RBC levels. Decrease in total antioxidant capacity, GSH, catalase, SOD, GPx levels and increase in MDA levels were seen in irradiated groups and ameliorative effects were seen in the groups pretreated with papaya leaf extract. In the present study, papaya leaf extract has shown moderate increase in antioxidant levels and reduced lipid peroxidation at sublethal and lower sublethal doses.
Abstract ID 0137
Role of Lutein in Alleviating the Effects of Electron Beam Radiation Induced Hematological and Biochemical Changes in Swiss Albino Mice
Vidya V 1 , A P Krishna 2 , Shrikant Patil 3 , Ronald Fernandes 4
1 K S Hegde Medical Academy, Nitte University; 2 Department of Physiology, K S Hegde Medical Academy, Nitte University; 3 Department of Physiology, K S Hegde Medical Academy, Nitte University; 4 Department of Biochemistry, Nitte Gulabi Shetty Memorial Institute of Pharmaceutical Sciences, Nitte University
Lutein is a naturally occurring xanthophyll pigment derived from α-carotene. It is abundantly present in Tagetes erecta L. (marigold) and also present in a few vegetables, fruits and in animal sources. Lutein was evaluated for its protective role in electron beam radiation induced damages in Swiss albino mice. The drug was optimized for its radioprotective activity. Lutein was administered orally at different doses of 5, 50, 250 and 500 mg/kg body weight and on the 15 th day, one hour after drug administration, the mice were irradiated with a lethal dose of 10 Gy. The mice were observed for 30 days post irradiation and the percentage survival was recorded and the optimum dose was calculated from the Kaplan- Meier survival analysis. The mice were further divided into vehicle control, radiation control, drug control and lutein treated prior irradiation groups. Lutein was administered at the optimized dose for 15 consecutive days and irradiated at 6 Gy on the 15 th day, one hour, after drug administration. The mice were sacrificed within 24 hours after irradiation. The haematological changes, the enzymatic antioxidants like glutathione-S-transferase, superoxide dismutase; non-enzymatic antioxidants like malondialdehyde and glutathione were determined in liver homogenates. The optimum radioprotective dose was found to be 250 mg/kg for lutein. There was no significant change in the antioxidant status between the groups. However the hematological status revealed a significant change only in the total white blood cell count and differential blood count levels but the red cell indices revealed no significant difference. Thus, it can be concluded that lutein enhances the leukocyte levels in the blood to maintain normal homeostasis in the body.
Abstract ID 0138
Tanacetum parthenium Leaf Extract Mediated Survival Protection in Lethally Irradiated Swiss Albino Mice
Prashanth Shetty 1 , Pooja S 2 ,Suchetha Kumari.N 3 , Jayaram Shetty 4 , Alex John Peter 5 , Jerish M. Jose 6
1 Department of Pharmacology , 2 Central Research Laboratory, 3 Department of Biochemistry, 4,5,6 Department of Oncology; 1 NGSM Institute of Pharma Sciences, Nitte University,Paneer, Deralakatte, Mangalore, Karnataka.; 2, 3, 4, 5,6 K. S.Hegde Medical Academy, Nitte University, Mangalore, Karnataka.
Search for less-toxic radioprotectors has spurred interest in the development of natural products. In Ayurveda, the traditional medicine, Tanacetum species have been used to treat ailments since ancient times throughout the world. Effects of the administration of different concentrations of Tanacetum parthenium leaf aqueous extract (TPLA), Tanacetum parthenium leaf ethanolic extract (TPLE) were investigated in Swiss albino mice. Mice (20-25 g) were randomly divided into 8 groups of ten animals each. The control group and the radiation group were treated daily with oral administration of saline for 15 days. Each subgroups of TPLA and TPLE were treated with doses of 50, 100 and 250 mg/kg daily for 15 days. On the 15 th day, all were irradiated with 10 Gy whole body irradiation. Survival was observed daily up to 30 th post-irradiation day. Data were analysed using the Kaplan-Meier survival curves. The significance difference in survival between control, radiation and treatment groups were observed (P < 0.001). Current studies revealed the protective effect of Tanacetum parthenium rendering high survivability in lethally irradiated mice.
Abstract ID 0139
Prevention of Ionizing Radiation Induced Damages by Clerodendron Infortunatum
Tiju Chacko and Aditya Menon
Pushpagiri Research Centre, Pushpagiri Institute of Medical Sciences and Research Centre, Tiruvalla 689101, Kerala, India
Several phytoceuticals and extracts of medicinal plants are reported to mitigate deleterious effects of ionizing radiation. The potential of hydro-alcoholic extract of Clerodendron infortunatum (CIE) was investigated for providing protection to mice exposed to gamma radiation. Oral administration of CIE bestowed survival advantage to mice exposed to lethal doses of gamma-radiation. The radiation-induced depletion of total blood count and bone marrow cellularity were prevented by treatment with CIE. The damage to cellular DNA, as evidenced from comet assay, and micronucleus index was also found to be decreased upon CIE administration. Radiation induced damages to intestinal crypt cells was also reduced by CIE. Studies on gene expression in intestinal cells revealed that there was a marked increase in bax/bcl-2 ratio in mice exposed to whole body 4 Gy gamma radiation and administration of CIE resulted in significant lowering of this ratio, suggestive of reduction of radiation induced apoptosis. Levels of expression of the DNA repair gene, atm was found to be elevated along with a reduction in the inflammatory cox-2 following CIE treatment in the intestinal tissue of irradiated animals. Thus the results suggest the beneficial use of Clerodendron infortunatum for mitigating radiation toxicity.
Abstract ID 0140
Reduction of Gamma Radiation Induced Damages by Hydro-Alcoholic Extract Of Nardostachys Jatamansi
Aditya Menon ,Tiju Chacko, Teeju Majeed, Praseetha R Nair, Sivaprabha V Nair and Cherupally Krishnan Krishnan Nair
Pushpagiri Research Centre, Pushpagiri Institute of Medical Sciences and Research Centre, Tiruvalla 689101, Kerala, India
The search for a non-toxic radioprotector has not yielded a promising result. Many antioxidant compounds though effective under in vitro conditions as radioprotectors, failed under in vivo settings due to their toxicity. Indian medicinal system uses a variety of plants with antioxidant potential, which may be harboring molecules with radioprotective property. In the present work, radioprotective property of Nardostachys jatamansi was investigated. Hydro-alcoholic extract of this plant provided protection to the cellular DNA and membrane from 4 Gy gamma radiation. Depletion of cellular antioxidant status was also prevented by this extract. Molecular level analysis in the intestine of mice showed a lower bax/bcl-2 ratio suggestive of reduction of radiation induced apoptosis. Expression levels of DNA repair gene, atm was found to be elevated along with a reduction in the expression of inflammatory gene cox-2. The extract also provided survival advantage to mice exposed to lethal doses of gamma radiation. These results suggest a possible radioprotective role for Nardostachys jatamansi.
Abstract ID 0142
Shielding Thickness Evaluation for Melter Cell in a Vitrification Plant
Brij Kumar , Tanmay S and Pradeep Bhargava
Health Physics Division, Bhabha Atomic Research Centre, Mumbai-85
Vitrification is the process for immobilizing the liquid high level waste generated from the reprocessing of the spent fuel from PHWR's in India. Vitirfication facility in a reprocessing plant contains joule melter for liquefying the spent fuel. Since the joule melter exists in the vitrification plant, it is important to check the shielding adequacy of the cell walls of the plant. This paper presents the results for estimation of dose rates outside the walls of various thicknesses of the plant, to meet the regulatory criteria. The methodology, in brief, involves estimation of the inventory of radioactivity in the melter, followed by calculation of the gamma dose rate at the given representative locations on the outer surface of the shield walls due to activity present in the melter. The dose rate, so estimated, must meet the acceptance criteria for occupancy of that area. The plant is designed to handle PHWR spent fuel cooled for a minimum period of 10 years. It contains 33 percent of 137 Cs activity of the gross beta activity present in the melter. Gross beta activity in the melter is 760000 Ci. In this paper, shielding evaluation of the wall thickness of the plant for given activity in the melter has been carried out. Density of glass is taken as 3.0 g/cc, density of concrete is taken as 2.39 g/cc. The shielding evaluations were carried out using the point-kernel code QAD-CGGP. The flux to-dose rate conversion factors (R/h per photon/cm 2 -s) are assumed to be as given in ANSI/ANS 6.1.1-1977. The dose rates calculated at the shield surface is compared with the AERB acceptance criterion of 0.1 mR/h for full time occupancy. However, this field may be increased when the occupancy is less than 8 h/day. It is found that concrete wall of 105 cm thickness provides the required shielding so as to reduce the dose rate to 0.03 mR/h which is well below the regulatory limit for full occupancy.
Abstract ID 0143
Shielding Evaluation of Shielding Flask Meant to Transfer Vitrified Hlw Canister
Tanmay Sarkar , Brij Kumar and P. Bhargava
Health Physics Division, Bhabha Atomic Research Centre, Mumbai-85
In vitrification facility a melter cell is designed to vitrify waste. Adequate cooling is required for vitrified waste product to maintain their temperatures within safe permissible limits due to less activity. The vitrified waste products are further transferred to Vitrified Waste Shielded Flask for transportation purpose. In this paper, a case study has been done for a shielded flask that contains 600000 Ci of activity. The canister in the shielded flask has activity, equivalent to about 6000 litres of High Level Waste of 100 Ci/l activity. Density of the vitrified waste product is 3 g/cc. Hence there is need to check the adequacy of shielding thickness. The methodology, in brief, involves estimation of the inventory of radionuclide, followed by calculation of the gamma dose rate at required representative locations on the outer surfaces of the shield. The total dose rate so calculated must meet the acceptance criteria for the transportation purpose. The shield evaluations were carried out using the point-kernel code QAD-CGGP. The flux to-dose rate conversion factors (R/h per photon/cm 2 -s) are assumed to be as given in ANSI/ANS 6.1.1-1977. Shielding evaluation for the shielded flask at the different locations have been carried out for the given dose rate at the surface and 1m distance from the flask. At the mid height of the canister the dose rates are calculated based on pre-specified contact dose rate and the corresponding shielding thicknesses are calculated. The shielding is provided with lead. For contact dose rates of 20, 50, 100, 150, 200 mR/h, dose rate at 1m distance is calculated to be 6.6, 13.4, 27.8, 45.3, 57.7 mR/h for respective lead thickness of 16, 15, 13.5, 12.4, 12 cm.
Abstract ID 0144
External Dose Conversion Factor from Canal Water
Pradeep Bhargava , Chitra S., Arti S. Mhatre and Kapil Deo Singh
Health Physics Division, Bhabha Atomic Research Centre, Mumbai-85
External dose needs to be estimated for the radioactivity discharged into the canal, as it constitutes one of the pathways of exposure to the public. Two activities are considered here: i) a walk along the bank of the canal ii) and the walk on the bridge. A concentration of 1 Bq/l is assumed here for the gross beta activity for the estimation of the dose conversion factor. A canal of width 14.39 m and the depth of 2.5 m is considered for this study. Length of the canal is taken to be infinite. Canal side wall is assumed to be the 25 cm thick concrete. Two points are selected, one on the bank, and the second on a bridge 1 m above the top surface of canal water. Dose Conversion factors for the person moving on the Bridge (at one meter above the water surface) and standing on bank of canal is estimated by using the QAD CG code for Cs-137. Dose conversion factors for the location mentioned above are found to be 1.11E-10Sv/hr/(Bq/l) and 1.55E-11Sv/hr/(Bq/l) for bridge and bank of canal respectively.
Abstract ID 0145
99m TC-Hynic-Labeled Peptide (CKCNGRC) and Peptide-Drug Conjugate C(KCNGRC)-Chlorambucil as Radiomarkers for Tumor Angiogenesis
Kusum Vats 1 , Drishty Satpati 1 , Haladhar Deb Sarma 2 , Sharmila Banerjee 1
1 Radiopharmaceuticals Chemistry Section, Radiochemistry and Isotope Group, 2 Radiation Biology and Health Sciences Division,, Bhabha Atomic Research Centre, Trombay, Mumbai, India
The asparagine-glycine-arginine (NGR) peptides home onto tumor vasculature by binding to CD13 receptors, upregulated in angiogenic tumor blood vessels. Chlorambucil (CLB) is an anticancer DNA-alkylating drug widely used against lymphocytic leukemia, non-Hodgkin's lymphoma, and other types of cancer. The specific localization of the drug, CLB in tumor cells can be enhanced on conjugation with a NGR peptide. The goal of this work was to determine the potential of 99m Tc-labeled NGR peptide as tumor angiogenesis marker and to study the pharmacokinetics of 99m Tc-labeled NGR-chlorambucil conjugate for its applicability to trace the tumor's response to therapy. The peptides c(KCNGRC) and c(KCNGRC)-CLB were manually synthesized by standard Fmoc solid phase peptide synthesis on Novasyn TGR resin and subsequently conjugated with indigenously synthesized HYNIC-Boc at the N-terminal residue of the peptide. The synthesized peptides were purified by semi-preparative HPLC. The HYNIC-peptide conjugate, HYNIC-c(KCNGRC) and HYNIC-peptide drug conjugate, HYNIC-c(KCNGRC)-CLB were radiolabeled with 99m Tc (185 MBq) by incubation with EDDA, tricine and stannous chloride (100 o C, 20 min). The radiotracers 99m Tc-HYNIC-c(KCNGRC) and 99m Tc-HYNIC-c(KCNGRC)-CLB were obtained in >95% radiochemical yield.as analyzed by reverse-phase HPLC with retention times of 13.5 min and 14.1 min respectively. The radiotracers were found to be stable in vitro in human serum 24 h post preparation. Biodistribution studies of 99m Tc-HYNIC-c(CNGRC) and 99m Tc-HYNIC-c(KCNGRC)-CLB were carried out in Swiss mice bearing fibrosarcoma tumor as well as in C57BL/6 mice bearing melanoma tumor. Preliminary studies indicate the tumor targeting potential of the two radiotracers. However, studies with different spacers (PEG) are likely to improve the pharmacokinetics of the radiotracers.
Abstract ID 0146
Effects of Two-Stage Gamma Irradiation on the Characteristics of Human Amniotic Membrane Decellularized with Bovine Gall Bladder Bile
M.S. Syama 1 , V.N. Vasudevan 2 , K K. Jayavardhanan 1 , T.Sathu 2 and Prashanth Varkey 3 1
Department of Veterinary Biochemistry; 2 Department of Livestock Products Technology College of Veterinary and Animal Sciences, Mannuthy, Kerala, 3 Department of Plastic and Reconstructive Surgery Jubilee Mission Medical College and Research Centre, Thrissur
Human amniotic membrane (HAM) is widely applied for the treatment of cutaneous wounds, ocular lesions and as tissue engineering scaffolds. Gamma irradiation at 25 kGy has been widely used to sterilize biomaterials. The current study hypothesized that when decellularized HAM was gamma irradiated in two stages - initial low dose irradiation at 2.5 kGy followed by storage at 4 o C for 24 hours and subsequent irradiation at 25 kGy - the cross-links formed during low dose irradiation may minimize the radiolytic changes occurring at higher sterilizing doses. The study assessed the effects of low dose irradiation at 2.5 kGy (IR2.5), two stage irradiation (IR2.5 + 25) and high dose irradiation at 25 kGy (IR25) on the characteristics of HAM decellularized with bovine gall bladder bile (BGB-HAM) and TritonX-100 (TT-HAM). The pepsin soluble fraction of both groups of HAM increased significantly at IR2.5+25 and IR 25 when compared to non-irradiated (NIR) and IR2.5 samples. In SDS-PAGE of the pepsin soluble fraction, there was reduced intensity of protein bands and protein smearing in case of BGB-HAM at IR2.5+25 and IR25 when compared to TT-HAM. The free amino group content did not differ significantly between the four treatments for both the groups of HAM. The resistance to enzymatic degradation after 48 hours of incubation with collagenase enzyme did not differ significantly between the four treatments of BGB-HAM, whereas it lowered significantly in TT-HAM. The tensile strength of both groups of HAM was significantly lowered at IR2.5+25 and IR25. The results indicate that two-stage irradiation did not ameliorate radiation induced biochemical and mechanical changes in the decellularized HAM. Moreover, some of the results are indicative of reduced radiolytic damage in BGB-HAM comp.
Abstract ID 0147
Directing Nanoparticle-Drug Complexes to Solid Tumor by Hypoxic Cell Radiosensitizer
S. Sreeja 1,2 and C.K. Krishnan Nair 1,2
1 Pushpagiri Institute of Medical Sciences and Research Centre and 2 MACFAST, Thiruvalla, Kerala. 689101
Hypoxic region in solid tumor is one of the major targets in cancer therapy. Specific targeting of cytotoxic drugs to hypoxic region in tumor can prevent hypoxia- associated expression of genes and enhance tumor regression. The hypoxic cell radiosensitizer - Sanazole (SAN), a nitrotriazole compound, has been shown to accumulate in the hypoxic microenvironment of solid tumor. In the present study, we complexed a cytotoxic alkaloid Berberine together with Sanazole to surface modified iron oxide nanoparticles to obtain the complex NP-BBN-SAN. The complexes were characterized by FTIR, XRD and TEM. The animals (Swiss albino) - bearing solid tumor on the hind limbs were administered with NP-BBN-SAN complexes. Tumor volume, the expression of hypoxia- inducible factors and histopathological alterations in tissues- tumor and liver- were also studied following the administration of the complex. The tumor volume increased in the control group compared to other treatment groups. There was some tumor regression in groups treated with NP-SAN, NP-BBN and BBN alone. The group treated with NP-BBN-SAN had significantly higher regression of tumor volume and down regulated expression of hif-1α and its target genes suggesting inhibition of tumor hypoxia. The tissue morphology and cellular architecture of tumor and liver emphasized the therapeutic use of the complexes. Thus the study revealed the potential application of hypoxic radiosensitizer, SAN and NP in targeted delivery of the cytotoxic alkaloid BBN to solid tumor for higher therapeutic efficacy.
Abstract ID 0149
Assessment of Insect Infestation in Gamma Irradiated Wheat Flour over Storage
B. R. Manupriya 1 , Lathika 1 , K. B. Shenoy 1 , S L. Patil 3 and H. M. Somashekarappa 2
1 Department of Applied Zoology, Mangalore University, Mangalore, India - 574199, 2 Center for Application of Radioisotopes and Radiation Technology (CAART), Mangalore University, Mangalore, India - 574199; 3 Department of Physiology, K.S.Hegde Medical Academy, Dearalakatte, Mangalore - 575018
Wheat was one of the first domesticated food crops used worldwide as a diet. Insect infestation is the foremost problem encountered during storage of wheat. The object of this work was to examine the insect infestation in control and irradiated wheat flour over storage at different habitats. 60 Co source gamma chamber was used to irradiate wheat flour at various doses (0.25 kGy, 0.5 kGy, 1 kGy, 5 kGy and 10 kGy). Irradiated wheat flour was divided into three groups along with a control. First group was stored in polyethylene pouches at room temperature (RT), second group was stored in plastic container at RT and third group was stored in plastic container at humid and dark place, for a year. Stored samples were examined twice in a month for insect infestation. Total insect population showed negative correlation with increased dosage in all habitats. In first group samples, control and 0.25 kGy showed infestation on 3 rd month of storage whereas 0.5, 1 and 5 kGy samples were infested on 4 th , 5 th and 6 th month of storage respectively. However, sample irradiated with 10 kGy had no infestation up to a year. Control and 0.25 kGy samples of second group showed infestation on 7 th and 8 th month of storage respectively while no infestation was observed in samples above 0.25 kGy over storage. In third group samples, insect infestation was more in control and less in 0.25 kGy on 9 th month rest did not show any infestation during storage. Plastic container storage would be preferable to avoid insect infestation in wheat flour at RT.
Abstract ID 0150
Characterization of A549 Cell Lines of Different Radio-Sensitivity
Murali MS Balla , Hansa Yadav and B.N. Pandey
Radiation Signaling and Cancer Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-400 085
Cancer stem cells (CSCs) have been shown to play major role in recurrence of tumor after radio/chemo therapy. However studies on mechanisms of CSC regulation during the course of cancer therapy are very limited. In this regard this work is mainly focused on generating A549 lung adenocarcinoma cells of different radio sensitivity, characterize the cells for CSCs. In the present study A549 lung adenocarcinoma cells of different radio sensitivity were generated by fractionated gamma radiation doses of 5Gy x 4 (R) and 5 Gy x 8 (RR) by clonogenic assay. CSCs were characterized by single cell assay and evaluated for expression of stemness markers like CD44 and CD24 by immunoflourescence. The clone forming ability (%) of A549 control, R and RR is 29.1±0.6, 41.9±5.1 and 42.7±1.1 respectively, suggesting the number of clone forming cells are more in R and RR cells compared to control. Furthermore, the D10 values (ionizing radiation required to reduce the viable number of cells by 90%) for control, R and RR were shown to be 6.6, 8.5 and 10 Gy respectively. Single cell clones expressed CD44 similarly and were negative for CD24 in control, R and RR cells. However the intensity of CD44 expression was more in R and RR cells compared to control. In summary the cell lines generated by fractionated doses of gamma radiation have different radio-sensitivity and these cell lines can be used as a model to study the radioresistance mechanisms in human lung cancer.
Abstract ID 0151
Fate of Gamma Radiation Exposure on Radio-Tolerant Insect Chironomus ramosus
Pallavi Gaikwad 1 ,2 , Rita Mukhopadhyaya 2 and B B Nath 1
1 Department of Zoology, S.P. Pune University, Pune -411007, India and 2 Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
Following Chernobyl nuclear plant explosion in 1986, various research groups investigated flora and fauna inhabiting the radioactive fallout zones. Chironomid midges attracted the attention of radiobiologists as they showed remarkable ability to survive in highly contaminated areas. Our previously published work also discussed tolerance of Indian tropical species of midge Chironomus ramosus to high doses of gamma radiation stress. Present work focuses on the fact that differential dose rates of gamma irradiation led to differences in survival pattern of Chironomus larva. Acute exposure of larvae with a dose rate of 55.6 Gy/min (HDR) showed LD 20 of 1700 Gy while larvae subjected to chronic exposure with a dose rate of 5.5 Gy/min (LDR) led to LD 20 of 2200 Gy. Enhanced larval lethality with increment in dose rate motivated us to investigate the mode and mechanistic basis of lethality. Early event of apoptosis was detected by Annexin-V assay and we could discriminate early and late apoptotic/necrotic cells. Biochemical assays showed activation of initiator and effector caspases during recovery under HDR. Mitochondrial membrane potential was measured to confirm intrinsic signalling cascade of caspases. Cleavage of PARP by effector caspase-3 was noticed after HDR and subsequent DNA ladder formation was confirmed by agarose and PFGE. These findings shed light on the mechanism of cellular death under gamma radiation stress and we conclude that the break-down in homeostasis in a radiation tolerant insect like C. ramosus resulted due to change in the dose rate of radiation.
Abstract ID 152
Preparation of 177 LU-Labeled Rituximab: Optimization of Radiolabeling Protocol and Pre-clinical Evaluation
Mohini Guleria 1 , Tapas Das 1 , Chandan Kumar 1 , Aruna Korde 2 , H. D. Sarma 3 , Sharmila Banerjee 1
1 Radiopharmaceutical Chemistry Section, Radiochemistry and Isotope Group, 2 Isotope Production and Application Division, 3 Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400085, India
Monoclonal antibodies (mAbs) possess high degree of affinity towards binding with specific antigens expressed by specific tumors. In this respect, radiolabeled mAb can be envisaged as a guided vehicle for delivering therapeutic doses of particulate radiation to the tumorous lesions. Rituximab as a chimeric mAb as well as the murine radiolabeled analogues viz. Bexxar ® ( 131 I-Tositumomab) and Zevalin ® ( 90 Y-Ibritumomab tiuxetan) have been approved by US-FDA for the treatment of non Hodgkin's lymphoma (NHL). In the present work, an attempt was made to radiolabel Rituximab, of chimeric origin obtained commercially as MabThera ® , with 177 Lu, a therapeutic radionuclide (E(beta) max = 498 keV, E(gamma) = 208, 113 keV, T 1/2 = 6.7 d), towards developing a radioimmunotherapeutic agent for the treatment of NHL. For the formulation of 177 Lu-labeled Rituximab, it was conjugated with a bifunctional chelating agent (BFCA) namely, p-NCS-benzyl-DOTA (BFCA:mAb = 1:10) and the mAb-BFCA conjugate, thus obtained, was purified by using pre-packed PD-10 sephadex column. The purified mAb-p-NCS-benzyl-DOTA conjugate was radiolabeled with 177 Lu by incubating the reaction mixture at 37°C for 1 h. Quality control was performed by high performance liquid chromatography employing an isocratic elution system using 0.05 M phosphate buffer and it was found that the radiolabeled complex could be prepared with a radiochemical purity of >95%. In-vitro cell binding studies carried out in human lymphoma cell lines revealed retention of affinity of 177 Lu-labeled Rituximab towards CD20 antigens. This was further confirmed by the inhibition studies where ~80% of inhibition was observed. In-vivo pharmacokinetic behavior of 177 Lu-labeled Rituximab, studied by biodistribution studies in normal Swiss mice, showed slow blood clearance along with low uptake in the vital organs. These studies indicate the potential of the 177 Lu-labeled Rituximab for further evaluation in human patients with clinically proven NHL.
Abstract ID 0153
Differential Sensitivity of Gamma Radiation in Chironomus and Human Haemoglobin
Bimalendu B. Nath
Stress Biology Research Lab, Department of Zoology, Savitribai Phule Pune University, Pune -411007
Hemoglobin (Hb) comprises a family of genes and proteins whose evolutionary history dates back to ~800MY. During this period, an unusual loss of all introns could be noticed in the Hb gene of an ancient insect genus Chironomus which evolved ~250 MY ago. Many such features of Chironomus haemoglobin (Ch-Hb) made this group intriguing. Hemolymph of chironomid midge larvae, popularly known as 'blood-worms', possess high content of extracellular monomeric Hb. Previous studies from our group reported remarkable tolerance of Indian midge Chironomus ramosus to gamma radiation. In the context of Hb, structural integrity of human hemoglobin (Hu-Hb) is lost even at 100Gy which is 30-fold less than the lethal threshold dose of Chironomus. Therefore, while exploring different facets of radiation tolerance in midges, we chose to investigate the status of Ch-Hb following high-dose gamma radiation. Accordingly, we have subjected Ch-Hb and Hu-Hb to gamma radiation and compared molecular integrity using biochemical and biophysical techniques. Findings revealed a profound tolerance of evolutionarily ancient Ch-Hb to high-dose gamma radiation in contrast to Hu-Hb for the maintenance of structural integrity. In order to gain insights for the 'loss of tolerance' of Hu-Hb to high-dose gamma radiation, we carried out sequence and structure-based bioinformatics analyses using Chironomus thummi thummi Hemoglobin (Ctt-Hb) sequence as reference. Our findings revealed that evolutionary history of substitution of hydrophilic amino acids could have affected stabilization of electrostatic interactions in the heme-cavity rendering Hu-Hb sensitive to gamma radiation. These results also substantiated physiological basis of radiation tolerance found in chironomid midges.
Abstract ID 0154
Exploitation of Microbial Resources for Radioprotector Development: Current Status at Institute Of Nuclear Medicine And Allied Sciences
Raj Kumar* 1 and Shravan Kumar Singh 2
1 Radiation Biotechnology Group, Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, Delhi-110054, India, 2 Radiation Biotechnology Group, Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, Delhi-110054, India
Microbial life can thrive in harsh environment including high radiation background. Development of radioresistance can be an outcome of the molecular synchronizing adaptability of the radioresistant microbe to radiation mediated oxidative damage. Molecular synchronization includes synthesis of novel biomolecules by radioresistance microbes to combat oxidative stress caused by ionizing radiation. Therefore, novel microbial products produced against ionizing radiation stress can be exploited as radioprotector for mammalian system too. Aligned with this hypothesis, we have isolated novel radioresistant bacteria and further purified a novel molecule RK-IP-006 with significant radioprotective efficacy. Isolated radioprotective biomolecule RK-IP-006 provide excellent whole body radioprotection (~80%) to the mice when administered 2h before lethal irradiation (9 Gy). RK-IP-006 showed significant radioprotection to proteins, enzymes and DNA against gamma radiation. RK-IP-006 provides in vivo protection to male reproductive, gastrointestinal and hematopoitic system against lethal doses of gamma radiation. RK-IP-006 able to protects macrophages, human PBMC and murine hepacytes against gamma radiation. Bio-informatics study revealed that RK-IP-006 acts as NK-1 receptor antagonist. Further, RK-IP-006 interacts with BARK1, AHR, NALP1 and NALP3 receptors and therefore, modulates molecular signalling that may contribute to radioprotection in biological system. Formulation development studies are underway for animal experimental purposes. If successful, formulation will be developed for Non-Human primate/human uses in future.
Abstract ID 0155
Radon Induced DNA Damage in Smokers Assessed using Cytokinesis-Block Micronucleus Assay
C. Meenakshi , K.Sivasubramanian, B. Venkatraman
Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamilnadu, India
Radon is a naturally occurring radionuclide in the environment, during decay it emits high linear transfer (LET) alpha particles. When radon exposure is accompanied by smoking it has been reported that lung cancer risk is higher. According to the BEIR (Biological effects of ionizing radiation) report of National Academies of sciences, for men exposed to radon at work, smokers are 10 times likely to get lung cancer compared to non-smokers. However, reports could not provide the same elevated level of risk to smokers as almost all studies were based on epidemiology often confounded with demographic, lifestyle and environmental factors making it difficult to establish a one to one correlation. In view of this, an in vitro study has been undertaken using cytokinesis-block micronucleus (CBMN) assay to investigate the synergetic effect between smoking and radon. Blood samples were collected, after prior consent, from healthy smoking and non smoking individuals and exposed in vitro to radon ranging between 0.3 - 12.6 mGy using a simple, portable irradiation assembly designed and tested at the Radiological Safety Division of IGCAR. The CBMN assays observed were micronuclei, nucleoplasmic bridges and nuclear bud. The frequencies of micronuclei in exposed smokers were extremely significant compared to exposed non-smokers (P < 0.0001) whereas the frequency of nucleoplasmic bridges was considered to be significant (P < 0.05). Micronuclei observed in smokers were higher than non-smokers by a factor of 3.9; the study indicates that for moderate smokers the risk of DNA damage is elevated by a factor of about 4.
Abstract ID 0156
Role of Cytokines Secreted from Irradiated Tumor Cells and Consequent Angiogenesis in Growth Inhibitory Bystander Effect in Fibrosarcoma Tumor Model
Sejal Desai, Nishad Srambikkal, Hansa D. Yadav , Amit Kumar, Anu Ghosh and B. N. Pandey
Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai-400 085
Radiation induced bystander effect (RIBE) is manifestation of radiation effect to cells which did not receive radiation. In present study, RIBE was studied in mouse (BALB/c) fibrosarcoma (WEHI 164 cells) tumor model by implantation of lethally g-irradiated (15 Gy) cancer cells mixed with unirradiated bystander cancer cells. Irradiated tumor cells resulted in significant decrease in growth of unirradiated (bystander) tumor cells. Histopathological analysis and other assays of these tumor samples showed decreased mitotic index, poor angiogenesis, increased apoptosis and senescence. To validate the results, angiogenesis study was conducted by in vivo imaging system using angiogenesis specific fluorescent dye. Compared to tumor in control animals, a significant decrease in fluorescence signal was observed in animals transplanted with mixture of tumor cells suggesting lower angiogenesis in these tumors. Growth inhibitory bystander effect was exerted more prominently by soluble factors from irradiated tumor cells than irradiated tumor cells themselves. Supernatant from irradiated cells showed increased levels of VEGF, Rantes, PDGF, GMCSF and IL-2 and decreased levels of IL-6 and SCF. Proteomic analysis of the supernatant from irradiated tumor cells showed differential expression of 19 proteins (15 upregulated and 4 downregulated). The major up-regulated proteins included heat shock cognate (71 kD), actin, alpha-enolase, galectin-1, elongation factor 1-gamma and phospho glycerate mutase. The down regulated proteins in these supernatant samples were annexin A2, lactate dehydogenase; protein S100 A4 and cofilin. In conclusion, our results provide deeper insight about nature and mechanism of secreted factors in damaging RIBE in in vivo tumor model, which may have significant implication in understanding the clinical outcomes under radiotherapy scenario.
Abstract ID 0157
New Techniques for Erythrosine Synthesis
Sachin G.V. Mhatre 1 , Soumyakanti Adhikari 2 , Mukund S. Kulkarni 1 , D.A.R.Babu 1 , K.S. Pradeepkumar 1
1 Health Safety and Environment Group, 2 Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
Iodination of fluorescein is carried out in several ways. In electrochemical technique of erythrosine synthesis, electric current is passed through a solution of sodium carbonate containing iodine and fluorescein at a divided cell. Electrochemical technique also describes erythrosine synthesis using different electrolyte solutions with varying anode material and varying current densities. In acidic medium, iodide is oxidized to iodine. Iodate is known to increases the iodine formation. However at low pH, fluorescein gets precipitated. High pH favours the fluorescein dissociation, leading to increase in iodination due to phenoxide ion formation however at higher pH the reactivity of iodine is reduced. Thus, a balance of pH with right choice of reactants is needed to optimize this reaction. Experiments were performed to test the feasibility of the reaction and reagents were finalized. Sample solutions of iodide and iodate along with varying concentrations of fluorescein were irradiated in 60 Co gamma chambers to provide gamma dose and measured spectrophotometrically. Sodium hydrogen carbonate was found to give the best yield thus was added at varying concentrations to study its influence on the reaction. pH of the solutions was varied from 8-14 to optimize the reaction. Concentration of reagents i.e. iodide, iodate, fluorescein and sodium hydrogen carbonate were finalized. Borax and molybdate were found the increase the reaction rate. 15 kGy dose is required for conversion of fluorescein to erythrosine at the experimental conditions studied. Thus, new techniques for erythrosine synthesis; using ionising radiation are developed. The developed technique can be scaled up for commercial purposes. To conclude, the radiation chemical process developed avoids use of toxic elemental iodine and is based on electrophilic halogenations by free radicals generated through water radiolysis to yield erythrosine.
Abstract ID 0158
The Supremacy of Phytochemicals in Radiation Biology Revisited
Department of Physiology,University of Calcutta, 92 APC Road, Kolkata 700 009
India is bestowed with extraordinary resources of plants. A huge number of plants are used as fruits, vegetables, cosmetic agents or for other purposes. Our laboratory has validated plant components present in common vegetables, fruits or natural beverages as radioprotecting agents in different models. Scientifically, we hypothesized their function in biological systems of amelioration of physiological stress created by radiation in terms of their chemical structures. We evaluated the phytochemicals in terms of in vitro, ex vivo or in vivo models of radiation. Different techniques such as biochemical assays, immune blot, microscopic analysis for histopathology, flowcytometry and scanning electron microscopy were employed to achieve the goal. We evaluated the antioxidant potential of the phytocompounds before being tested into ex vivo or in vivo systems. We evidenced a number of compounds in molecular depth with substantiation of cellular mechanism in the gamma radiation exposed models. We delineated the fact that these phytocompounds have enormous power due to their resident chemical structures. We have shown that Gossypetin, Quercetin, Rutin, Naringin, Ferulic acid, Epicatechin, coconut water concentrate or its major component Shikimic acid are capable to challenge the reactive free radicals. They either inhibit the redox sensitive inflammatory signaling events leading to NFκB activation or activate reciprocal transcription factor Nrf2. We could show the cross talk, expression or deactivation of certain signaling molecules, ultra structural morphology of tissues substantiating the molecular mechanisms involved. Thus, we have ample evidences to promulgate these compounds as radioprotective drugs in therapeutic purposes.
Abstract ID 0159
Protective Effect of Tanacetum Parthenium Leaf Extract on Radiation Induced Chromosomal Aberrations in Swiss Albino Mice
Pooja S 1 , Prashanth Shetty 2 ,Suchetha Kumari.N 3 , Jayaram Shetty 4 , Alex John Peter 5 , Jerish M. Jose 6
1 Central Research Laboratory, 2 Department of Pharmacology, 3 Department of Biochemistry, 4,5,6 Department of Oncology, 1, 3, 4, 5,6 K. S.Hegde Medical Academy, Nitte University, Mangalore, Karnataka., 2 NGSM Institute of Pharma Sciences, Nitte University,Paneer, Deralakatte, Mangalore, Karnataka.
Ionizing radiation imparts deleterious effects on the cell by causing chain reactions due to the formation of radicals along with chemical modification which may reflect on the chromosomal structure, behavior and also intercalation of DNA sequence inside the cells during treatment. The formation of dicentric, ring, fuse chromosome, gaps, breakage, and other structural changes are consequences of exposure to ionizing radiation. To investigate the protective effect of Tanacetum parthenium leaf extract on the sub-lethal total body, Electron beam radiation induced chromosomal aberrations in Swiss albino mice were studied. Swiss albino mice were divided into four groups. Group 1 (control) normal mice and Group 2 (Radiation control) received oral administration of saline for 15 days. The treatment groups including a daily dose of 100 mg/kg Tanacetum parthenium leaf aqueous extract (TPLA), Tanacetum parthenium leaf ethanolic extract (TPLE) for fifteen days before (pre-treatment) comprising Group 3 and after (post-treatment) is considered as Group 4. On the 15 th day, all were irradiated with 6 Gy whole body irradiation for pre and post-irradiation treatments. Chromosomal aberration was evaluated in the bone marrow cells of the sacrificed animals according to the method followed by Schmid et al. Obtained data were scored and statistically analysed. Radiation induced chromosomal aberrations reduced in the pre-treated mice which was statistically significant compared to radiation control group. Current study explicitly indicated that Tanacetum parthenium leaf extract possess preventive protection against radiation induced chromosomal damage. Intense research is required to quantify the mechanisms involved in the protective effect.
Abstract ID 0160
In Vivo DNA Damage Protection to Lethally Irradiate Mice: Role of Podophyllotoxin and Rutin Hydrate Combination
MH Yashavarddhan 1, 2 , Sandeep K. Shukla 1 , Nitya N. Srivastava 1 , Mrutyunjay Suar 2 , Manju L. Gupta 1
1 Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, SK Mazumdar Marg, Delhi-110054; 2 KIIT School of Biotechnology, KIIT University, Bhubaneswar, Odisha-751024, India.
Ionizing radiation induced DNA damage may lead to mutation, cancer, and cellular death. Present study was carried out to elucidate the DNA protective ability of a formulation (G-003M), a combination of Podophyllotoxin and Rutin hydrate, in murine blood and bone marrow cells under in vivo condition. The formulation was administered intramuscularly to mice 1 h prior to Co60 gamma irradiation exposure. Mice were assigned to groups that received one of the following treatments: Un-treated, G-003M alone, 9 Gy irradiated and G-003M pre-administration followed by 9 Gy radiation exposures. The levels of DNA damage response proteins; gamma-H2AX, p53BP1, phosphor-ATMser-1981, DNA-PK, Ku-80, Ligase-IV, MRE-11, Rad-50 and NBS-1 were studied by immunocytochemistry method at various time points. Additionally, ROS and cell cycle studies of individual compounds were analyzed to understand the mode of action of the formulations. In 9 Gy irradiated group, significant (p<0.01) time dependent changes was observed in all the proteins in contrast to untreated with maximum change at 1 hr. G-003M treated and irradiated group has shown up-regulated DNA-PK, Ku-80, Ligase-IV, MRE-11, NBS-1 and Rad-50 foci and down-regulated levels of gamma-H2AX, p53BP1 and phosphor-ATMser-1981foci when compared to radiation alone group. Cell cycle study with Podophyllotoxin has indicated temporary G2/M arrest which was found mediated through Cyclin-B1 protein. The other compound, Rutin hydrate has shown strong ROS scavenging property. These results indicate the DNA protective ability of G-003M could be due to altering levels of repair proteins, free radical scavenging and temporary arrest of the cell cycle.
Abstract ID 0162
Ferulic Acid Ameliorates Radiation Induced Duodenal Inflammation by Modulating Nuclear Factor Kappa Beta-Nuclear factor-2 Erythroid Related Factor-2 Cross Talk
U. Das 1 , K. Manna 1 , A. Khan 1 , A. Sengupta 1 , S. Biswas 1 , A. Chakraborty 2 and S. Dey 1 *
1 Department of Physiology, University of Calcutta, 92, APC Road, Kolkata 700 009., 2 Department of Radiation Biology, UGC-DAE CSR Center Kolkata, Kolkata, West Bengal, India.
Ionizing radiation generates oxidative stress and inflammation. The current study aimed to evaluate the effect of ferulic acid (FA) on increasing doses of ionizing radiation mediated oxidative stress and inflammation using in vivo murine duodenum. To delineate the hypothesis we exposed mice with 2.5, 5 and 10 Gy γ-radiation doses in presence and absence of the (FA). FA was administered orally at a fixed dose of 50 mg/kg bw for 5 days before radiation exposure. γ-radiation manifested higher lipid peroxidation (LPO), decreased reduced Glutathione (GSH) level and lower activity of Super Oxide Dismutase (SOD) and Catalase (CAT) that were reversed by FA pretreatment. Moreover, FA pretreatment ameliorated (1) increased phosphorylation of IκBα, (2) nuclear translocation of NF-κB (3) increased IL-6, TNF-α protein expression in tissue, (4) mitochondrial membrane potential change and (5) infiltration of inflammatory cells into intestinal sections due to increasing doses of irradiation. FA treatment increases the nuclear translocation of Nrf2 which in turn combated to overcome the systemic oxidative stressed condition. There were interaction between NF-κB and Nrf2 as evidenced Fluorescence microscopy. Moreover, the intestinal histopathology presented explicit morphological distortions after radiation with increasing doses. There was infiltration of inflammatory cells indicating intestinal inflammation. The SEM photomicrographs revealed distinct morphological changes which include oxidative stress induced damage in duodenum, distortion of gap junctions that were refurbished by FA treatment. Therefore, treatment with FA prior to irradiation prevented radiation induced inflammation and intestinal injury at all doses and restored the usual morphology of this important intestinal segment.
Abstract ID 0163
Attenuation of Radiation Induced Mouse Bone Marrow Stem/Progenitor Cells Injury by Pre-administration of Podophyllotoxin and Rutin Combination
Rajiv Ranjan 1 , Abhinav Singh 1 , Bhargab Kalita 1 , Manju L. Gupta 1
1 Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences, Brig.S.K Mazumdar Marg, Delhi 110054, India.
Hematopoietic system plays pivotal role in functioning and survival of animals. This system delivers functional circulating cells to blood and other lymphatic organs. Renewal of these cells exclusively depends upon bone marrow stem/progenitor cells proliferation and differentiation. The formulation used in current study is a combination of two bioactive compounds (Podophyllotoxin and Rutin). The study was undertaken to decipher the radioprotective potential of Podophyllotoxin and Rutin in combination towards bone marrow stem/progenitor cells protection in lethally irradiated mice. Formulation (Podophyllotoxin and Rutin) coded as G-003M was administered intramuscularly prior (-1 h) to irradiation. Mice were sacrificed as per experimental design. The key markers used in this study are CD-34, Sca-1, CD-117 of the stem/progenitor cell lineages, cytokines (G-CSF, GM-CSF). Besides, colony forming ability and cytogenetic aberrations assay were also studied. Standard protocols were used for all the studies. G-003M pre-treatment significantly increased the expression of CD-34 (p< 0.001), Sca-1 (p< 0.05) and CD-117 (p< 0.001) as compared to radiation only group and the same was comparable to controls on 35 th day of experimentation. G-CSF and GM-CSF concentration in pre-treated groups was found increased at 24 h. Drug had significantly enhanced colony forming ability (p<0.001) and reduced chromosomal damage (p< 0.001) in the bone marrow cells. This study explicitly confirmed the ability of the combination of Podophyllotoxin and Rutin in delivering protection to bone marrow stem/progenitor cells and maintaining their proliferation and differentiation ability. Regulated cytokines concentration also proved protection to the bone marrow microenvironment.
Abstract ID 0166
Remineralising Efficacy of Tooth Mousse Plus (ACP CCPF) on Radiated Tooth
Priya 1 , Mithra N Hegde 2 *, Nidarsh D Hegde 3 , Suchetha Kumari N 4 , Ganesh Sanjeev 5
1 Nitte University; 2 Dept. of Conservative Dentistry and Endodontics, ABSMIDS, Nitte University; 3 Dept. of Oral Maxillofacial Surgery, ABSMIDS, Nitte University; 4 Dept. Of Biochemistry, KS Hedge Medical College, Nitte University; 5 Microtron Center, Mangalore University
Dental complication is the common problem faced all over the world. Subjects with poor oral hygiene and patients undergoing radiotherapy for oral cancers are developing signs of decalcification of enamel, lesions and Caries. A well designed treatment is necessary to safeguard the tooth enamel surface before and after radiation, only then the caries on the enamel surface can be arrested by re-hardening it and ultimately converting them to the normal healthy condition. To determine the Annealing effect of radiated tooth by testing maximum micro hardness of the teeth before and after 30 days of radiation by the application of Remineralising agents. In our study, we collected 30 intact caries free human molar teeth and were sectioned mesio-distally. The sectioned teeth were divided into 3 groups as control, ACP CCP Coated teeth and ACP CCPF coated teeth. Samples were subjected to Radiation dosage of 70Gy and the microhardness profile was assessed before, after and after 30 days of radiation treatment. The results obtained were statistically analysed by performing bonferroni adjustment for pair wise comparisons and one way ANOVA for multiple comparison test at P<0.05 level of significance. The microhardness test values showed that teeth had acquired remineralising ability when tested for hardness after 30 days incubation period supplemented with remineralising agents maintained in artificial saliva. The results obtained were statistically significant. Teeth samples treated with Tooth Mousse Plus showed better remineralisation efficacy after radiation maintained under oral hygienic environment over a period of time.
Abstract ID 0168
Radiation Responsive Promoters of Deinococcus radiodurans
Ananganti Narasimha 1 , Bhakti Basu 1 and Shree Kumar Apte 1
1 Molecular Biology Division, Bhabha Atomic Research Center, Trombay, Mumbai-400085, India.
Deinococcus radiodurans (DEIRA) is the most radiation resistant bacterium known to date. It withstands 10 kGy of gamma radiation, which is around 2000 times higher than the lethal dose for humans. The bacterium also survives other DNA damaging stresses such as UV radiation, chemical mutagens and years of desiccation. In response to DNA damage, the organism selectively expresses a number of genes, majority of which are involved in DNA repair. The precise mechanisms involved in induction of radiation-responsive genes of DEIRA have been investigated. A 17 bp degenerate palindromic sequence called Radiation and Desiccation Response motif (RDRM) and a trans-acting repressor DdrO have been implicated in the gamma radiation responsive gene regulation in DEIRA. We cloned 10 RDRM containing promoters and fused them to GFP reporter to understand the radiation inducible gene regulation in DEIRA. The promoter activity of these constructs was low, as compared to 5 non-RDRM promoters, under normal growth conditions. The promoter activity was further repressed in E. coli cells over-expressing the DdrO protein, providing the first in vivo evidence for the role of DdrO in the negative regulation of these genes. Promoter activity of most RDRM-based promoters was induced several fold during post-irradiation recovery. Removal of RDRM sequence from selected RDRM-promoters resulted in increase in the basal promoter activity, but completely abolished radiation induction of the corresponding promoters. Thus, RDRM sequence is involved in both repression of gene expression under normal growth conditions as well as induction of gene expression following DNA damaging stresses.
Abstract ID 0170
Efficiency of Deinococcus radiodurans and Escherichia coli Single-Stranded DNA Binding Protein in RecA Mediated Inverse Strand Exchange
Aman K. Ujaoney and Bhakti Basu
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai-400085, India
Single-stranded DNA binding protein (Ssb) is an essential housekeeping protein involved in DNA replication, recombination and repair. It mainly serves two types of functions viz. (a) protection of single stranded DNA from nucleolytic degradation by physical binding and (b) interaction with other replication/repair proteins through its acidic C-terminal tail. Ssb protein of Deinococcus radioduransis uniqueas two oligonucleotide/oligosaccharide binding (OB) folds are present in a single protein which is about twice the size of E. coli Ssb, its C-terminal half being more similar to other eubacterial Ssb proteins. Between the two Ssb proteins, E. coli Ssb showed higher affinity for ssDNA than D. radiodurans Ssb as adjudged by electrophoretic mobility shift assays. Deinococcal Ssb and RecA have been shown to execute inverse strand exchange which involves preferential interaction with double stranded DNA. Here we assessed cooperation between Ssb and RecA proteins from D. radiodurans and E. coli to ascertain if inverse strand exchange was indeed a unique feature of deinococcal proteins. Our results show that inverse strand exchange was executed by both D. radiodurans RecA and E. coli RecA along with D. radiodurans Ssb as well as E. coli Ssb. However, D. radiodurans Ssb was more efficient in forming RecA mediated nicked circular product than E. coli Ssb. Lower affinity of D. radiodurans Ssb towards ssDNA may be a useful feature in inverse strand exchange.
Abstract ID 0171
Radiation DNA Damage Assessment by Flowcytometry and Polymerase Chain Reaction
S.Tewari 1 , KKhan 1 , S.P. Mishra 2 , N. P. Awasthi 1 , M. Rastogi 2 , G. R. Agarwal 3 and N. Husain 1
Department of Pathology 1 ,Dr. Ram Manohar Lohia Institute of Medical Sciences ,Lucknow; Department of Radiation Oncology 2 Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow Department of Radiodiagnosis 3 Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow.
The diagnostic and therapeutic radiation fields are prudently planned to minimize the risk to non target tissues while maximizing the dose to target, still its side effects are inevitable. The present study evaluates DNA damage caused in patients exposed to diagnostic radiation, radiotherapy and normal controls by Long Range PCR and Flow cytometry. DNA was isolated from blood of 30 patients (10 low dose (LD), 10 high dose (HD) and 10 no exposure control (NEC)). Long (13kbp) and short (200bp) conventional PCR amplicons of ß-actin gene were used to quantify DNA damage by agarose gel electrophoresis. For gamma H2AX estimation fresh samples within 1hr of collection were used to isolate lymphocytes. Cells were permeabilized and stained by PE conjugated gamma H2AX and FITC conjugated CD45 and 10,000 cells were analyzed for gamma H2AX positivity. The mean ratio of long to short fragment was higher in NEC and lower in HD and LD. Low dose samples resulted in a comparatively thin band of 13kbp and high dose resulted in a very faint band as compared to normal. The gamma H2AX positive cells were higher (1.2% ±0.05) in radiotherapy patients compared to normal (0.09%±0.01) and low dose (0.08%±0.04). This study may find its application to detect DNA damage caused by low dose radiation by PCR which has not been previously utilized to evaluate radiation DNA damage. The flow cytometric gamma H2AX assay also detects the DNA damage; however more samples are needed to validate the assay.
Abstract ID 0174
Evaluation of 177 LU-DOTMP A Bone Pain Palliatve in Osteosarcoma Cells
Chandan Kumar , Rohit Sharma, Tapas Das and Sharmila Banerjee
Radiopharmaceutical Chemistry Section, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Trombay, Mumbai - 400085, India
Many malignant tumors especially those of the prostate, breast and lung, in advanced stages metastasize in bone and induce severe bone pain. Bone seeking radiopharmaceuticals which selectively deliver therapeutic doses of particulate radiation to bone while sparing other tissues are preferred for this purpose. Medium energy beta emitting radionuclide such as Lutetium-177 [498 keV (78.6%), T 1/2 = 6. d] is preferred for this therapy as the possibility of bone marrow ablation is significantly less. within this respect 177 Lu-DOTMP [1, 4, 7, 10-tetraazacyclododecane- 1, 4, 7, 10-tetra (methylene-phosphonic acid)}, has shown considerable promise as a bone pain palliative agent. Thus, it was of pertinent interest to carry out in-vitro evaluation studies in osteocarcinoma cell line to investigate the underlying mechanism of cellular toxicity. DOTMP was labeled with 177 Lu at room temperature and adequate radiochemical purity (~95%) was determined by paper chromatography. Cell binding studies of 177 Lu-DOTMP were carried out in osteocarcinoma cells (MG63) after induction of bone mineralization. Cellular toxicity studies were carried out with incubation of varying amounts of 177 Lu-DOTMP for 48h and compared with equivalent amount of DOTMP. Maximum binding of 177 Lu-DOTMP in MG63 mineralized bone was found to be (49.64 ± 1.13) % while inhibition was less than 1%. Nearly 14% cell death was estimated by Lactate Dehydrogenase assay in MG63 cells treated with 3.7 MBq of 177 Lu-DOTMP compared to control. Apoptosis studies were carried out by quantifying DNA fragmentation and it was found that DNA enrichment factor was 1.3 compared to control in MG63 cells treated with 3.7 MBq of 177 Lu-DOTMP. These studies indicate that the 177 Lu-DOTMP binds to mineralized bone cells and induces apoptotic cell death which results in palliation of bone pain.
Abstract ID 0175
In-vitro Evaluation of 188 Re-Dimercaptosuccinic Acid Complex for Potential Applications in Cancer Therapy
Rohit Sharma , Viju Chirayil, Chandan Kumar, Madhava B. Mallia and Sharmila Banerjee
Radiopharmaceutical Chemistry Section, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Trombay, Mumbai - 400085, India
Rhenium-188 is an attractive candidate for a wide variety of radiotherapeutic applications. Its high energy beta particle (E ß = 2.1 MeV) with concurrent emission of a gamma photon (Eγ = 155 keV) suitable for imaging as well as its versatile chemistry for radiolabeling with a variety of biological vectors, make 188 Re an attractive radioisotope for treatment of a wide variety of cancers such as metastatic bone cancer, non-resectable liver cancer, non-melanoma skin cancers and radiosynovectomy of big joints. Pentavalent 188 Re-dimercaptosuccinic acid [ 188 Re (V) DMSA] is a beta-emitting analogue of 99m Tc (V) DMSA, a tracer that is taken up in a variety of tumors and bone metastases. The aim of the present study is to evaluate the stability of [ 188 Re (V) DMSA], its uptake in human osteocarcinoma (MG-63) cells and human breast adenocarcinoma (MCF-7) cell lines as well as to assess its cellular toxicity. 188 Re-DMSA was prepared using a DMSA freeze-dried kit developed in-house and 188 Re from a 188 W- 188 Re generator. Radiochemical purity of the preparation was determined by ascending thin layer chromatography in normal saline and it was found to be >95%. Cellular toxicity studies were carried out with varying amounts of 188 Re-DMSA and compared with equivalent amount of DMSA ligand. Cell viability was assessed by LDH assay and apoptosis by DNA fragmentation. Nearly 35% more cell-death was observed in MG63 cells treated with 3.7 MBq of 188 Re-DMSA as compared to that observed with control. Estimation of DNA fragmentations was carried out to study apoptosis and it was found that DNA enrichment factor was 6.37 compared to the control in MG-63 cell lines. These studies indicate the potential of 188 Re-DMSA in inducing death in cancer cells and its utility in cancer radiotherapy.
Abstract ID 0176
Microrna-31 Mediates Radiation Induced Apoptosis Selectively in Malignant Tumour Cells with Dysfunctional P53
Ashish Kumar 1 , Prabuddho Mukherjee 1 , Bincy Babu 1 , Sudhir Chandna 1
1 Division of Natural Radiation Response Mechanisms, Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Mazumdar Marg, Delhi-110054, India
The protein p53 has been recognized as an important radio-responsive protein which functions mainly through transcriptional control of its target genes and microRNAs that target multiple response pathways. In this study, we investigate a putative link between p53 functionality and microRNA-31 expression that largely contributes to cellular transformation/malignancy and also establishes the role of miR-31 in radiation-induced cell death. The expression of miR-31 is found to be attenuated in cells in successive stages of cancer progression. In cells with dysfunctional p53, miR-31 suppression imparted significant protection against irradiation and corresponding overexpression caused significant cell death in tumour cells indicative of a pro-apoptotic role of miR-31. In contrast, manipulating miR-31 expression in cell lines with functional p53 did not show any significant effect on radiation-induced growth inhibition or cell death. In silico prediction followed by chromatin immunoprecipitation assay ruled out direct transcriptional repression of miR-31 by p53. Pathway specific PCR array analysis was also performed to identify the targets of miR-31. Additionally, inhibition of miR-31 was also found to affect the migratory proficiency of transformed and cancerous cells. Collectively, these findings suggest a pro-apoptotic role of miR-31 in tumour cells with dysfunctional p53. Since nearly half the tumour types are known to carry inactivated p53, our study may help in improving therapeutic strategies.
Abstract ID 0177
Low Dose Hyper-radiosensitivity at Progressive Stages of Neoplastic Transformation is Associated with Altered Cell-Cell Interactions
Ankit Mathur 1 , Sudhir Chandna 1
1 Division of Natural Radiation Response Mechanisms, Institute of Nuclear Medicine and Allied Sciences, Brig.S.K. Mazumdar Road, Timarpur, Delhi, India
Involvement of cell-to-cell communication in cancer progression as well as in radiosensitivity has become a significant issue in radiation biology due to experimental evidence accumulated since early 1990s. The lack of a satisfying explanation may come from the complexity of the disease, evolving through various stages during cancer progression, in which transformed cell gain different phenotypes. Previous studies from our laboratory have clearly shown the role of cell-cell interactions in low-dose radio-sensitivity as well as radiation-induced cell migration/invasion in normal and cancerous cells. Here, the question of involvement of carcinogenesis processes in the alteration of radiosensitivity at low doses was addressed, considering cell-cell and cell-matrix interactions. Two in vitro transformation models using NIH3T3 (murine fibroblast) and primary human thyroid cells and their transformed sublines were developed. Secondary foci formation, alterations in cellular morphology, saturation density, growth properties, anchorage dependency as well as tumorigenicity in nude mice were taken as early and late stage markers of transformation. Despite phenotypic alterations of transformed cells, modifications of adhesive and gap junctional interactions were observed at various stages of neoplastic progression in terms of adhesion molecule expression, pattern of direct cell-cell interacting sites, cell cohesion, cytoplasmic distribution of actin filaments. Altered expression and perturbed association of these proteins was further corroborated with significant decrease in cell migration. Most important however, these transformed cells showed significantly higher radiosensitivity at low doses of radiation (<50 cGy) than their parental cell strain. This study thus demonstrates that increased transforming potential and low dose radiosensitivity is associated with the cell adhesion property.
Abstract ID 0178
Combination of Bioactive Compounds: A Safe Prophylactic Remedy against Varied Types of Radiation Exposures
Manju Lata Gupta
Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences, Brig.S.K Mazumdar Marg, Delhi 110054, India.
Development of safe and effective radiation countermeasures, even after several decades, could not yet lead to tangible yield due to inherent toxicity as a prime cause. Present deliberation has focused on protective ability of a combination of two herb based compounds (A and C) against lethal radiation induced damage to cellular bio-molecules. Protection to hematopoietic, GI and respiratory system in lethally irradiated mice has been also addressed. Mechanics is explained based on scavenging of radiation induced reactive oxygen and nitrogen species by C. A and C in combination had apparently up-regulated antioxidant, anti inflammatory and DNA damage and repair (NHEJ) pathways. Compound C, being an excellent ROS-RNS scavenger, was also screened for its protective potential to salivary glands during head and neck cancer radiotherapy treatment which often results into xerostomia due to hypo-function of this organ. Study demonstrated that C mediated sustained saliva secretion against lethal/sub-lethal radiation exposure to mice in single and fractionated doses. Besides, salivary glands were also observed to be integrated in their histopathological contour. Glioma cell lines pretreated with the same compound and irradiated to different doses of radiation did not show any protection. Also, low dose exposure to radiation is known to cause genomic instability, mutations and carcinogenicity. Compound C pretreatment to mice exposed to 1-2 Gy revealed significant protection to bone marrow DNA studied in the form of cytogenetic aberrations. The study reveals that these two bioactive compounds (A and C) in combination as well as alone may come out as an appropriate answer in delivering protection against planned/unplanned, whole body and hemi-body radiation exposure. Further studies are in progress.
Abstract ID 0179
Radioresistant Spodoptera frugiperda 9 Insect Cells Display Excessive Resistance to "Endoplasmic Reticulum" Stress and Calcium Disturbances via Pre-Emptive Activation of Unfolded Protein Response Pathway
Ayushi Guleria 1 and Sudhir Chandna 1
1 Division of Natural Radiation Response Mechanisms, Institute of Nuclear Medicine and Allied Sciences (INMAS), Brig. SK. Mazumdar Road, Delhi-110054.
Endoplasmic Reticulum (ER) performs multiple cellular functions such as proper folding of newly synthesized proteins and calcium homeostasis. ER stress triggers unfolded protein response (UPR) that attempts to restore normal ER function and resists damage-induced cell death. Lepidopteran Sf9 insect cells (derived from Spodoptera frugiperda) display 100-200 times higher radioresistance than mammalian cells. We have earlier reported that gamma-radiation doses <1000 Gy fail to trigger increase in cytosolic calcium in Sf9 cells, indicating resilience to calcium/ER disturbances. Therefore, we investigated response of Sf9 cells to ER stress inducers, Thapsigargin (inhibitor of sarcoplasmic/endoplasmic Ca 2+ ATPase SERCA), Tunicamycin (a protein N-glycosylation inhibitor) and Brefeldin-A (blocks ER to Golgi protein transport). As compared to mammalian cells, Sf9 cells were far more resistant to thapsigargin, tunicamycin and brefeldin-A-induced cell death and exhibited significantly lesser induction of ROS and RNS. Further, in complete contrast to mammalian cells, all these ER stress inducers could not induce any significant change in cytosolic and mitochondrial calcium in Sf9 cells indicating a more robust ER stress response. Moreover, we observed attenuated CHOP-eIF2alpha-CaMKII calcium signalling despite significant basal expression of these proteins in Sf9 cells. Also in response to radiation, Sf9 cells show accumulation of the CHOP-CAMKII proteins at sub lethal doses indicating protective interference in contrast to their complete absence at lethal doses. All these observations suggest that this attenuated calcium signalling and acute UPR response is an innate characteristic of these radioresistant Sf9 cells and could be working as pre-emptive prosurvival mechanism to enhance stress resilience.
Abstract ID 0180
Inflammatory Network in Post-radiotherapy Complications including Secondary Cancers
Sonia Gandhi and Sudhir Chandna
Division of Natural Radiation Response Mechanisms, Institute of Nuclear Medicine And Allied Sciences, Brig. S.K. Mazumdar Marg, Timarpur, Delhi-110054, India
Radiation therapy has been considered as an integral component in the treatment of patients with varied types of cancer. However, effective treatment is impeded by the inherent and/or acquired resistance to the cytotoxic effects of Radiotherapy. Radiation rapidly and persistently alters the soluble and insoluble components of tissue microenvironment, affecting the tissue composition and hence signaling between cells. These alterations in microenvironment can contribute to carcinogenesis modifying tissue response to radiotherapy. Hence, understanding the signaling pathways inducing radiation resistance will not only help in realizing the full potential of radiotherapy, but also identifying drug targets for radiosensitization. We hereby review various studies to evaluate and elucidate recent data demonstrating the pivotal role of inflammatory pathways in cancer progression and modulation of radiation response. Ionizing radiation has been shown to induce accumulation of macrophages, accompanied by margination and the infiltration of tissues by neutrophils. The activation of transcription factors modulates the expression of pro-survival genes regulating inflammation, anti-apoptosis, invasion and angiogenesis pathways, conferring tumor cell radio-resistance and producing complications and secondary cancers. The systemic effects of pro-inflammatory cytokines are associated with fatigue, depression and cognitive impairment, affecting quality of life before, during and after treatment. Since the pathogenetic mechanisms underlying radiation-induced tumourigenesis are not well-defined, studying how the inflammatory signaling pathways induced by ionizing radiation promote secondary malignancies can yield important insights into cellular and tissue responses to radiation induced injury. This will provide help in improving the clinical outcomes and reducing normal tissue side-effects as well as post radiotherapy complications.
Abstract ID 0181
Radiation-induced Phosphorylation of P53 Protects Radioresistant Spodoptera frugiperda 9 Cells by Suppressing MicroRNA-31-Bim-Bax Mediated Apoptosis
Ashish Kumar 1 , Sudhir Chandna 1
1 Division of Natural Radiation Response Mechanisms, Institute of Nuclear Medicine And Allied Sciences, Brig. S.K. Mazumdar Marg, Timarpur, Delhi - 110054, India
In this study, we demonstrate the role of microRNA-31 (miR-31) in the regulation of radiation-induced apoptosis in model radioresistant insect cell line Sf9 (derived from the ovaries of insect Spodoptera frugiperda) which carries well-conserved apoptotic response. We also investigated the miR-31 expression regulation by p53 homologue in these cells. Our initial in silico analysis confirmed perfect conservation of mature miR-31 across various insect orders, hence we designed biotinylated probes from Bombyx mori sequence for successful detection of miR-31 in Sf9 cells. Further experiments displayed a decreased level of miR-31 following radiation doses less than 1000 Gy while at higher doses (>1000Gy) miR-31 expression was found to be significantly upregulated, inducing caspase activity/cell death. Radiation-induced alteration in Sf-p53 showed inverse expression relation with miR-31. Sf-p53 phosphorylation and accumulation was observed only following sublethal doses (200Gy). Dot blot following ChIP assay strongly suggests that phosphorylated p53 bound at miR-31 locus and is responsible for its downregulation, while at higher doses p53 failed to accumulate, resulting in to overexpression of miR-31 and cell death induction. Moreover, lethal radiation doses failed to change Bax/Bcl2 expression but caused Bax translocation to mitochondria in a Bim-dependent manner, which was importantly inhibited by antisense-miR31. These results hence show regulation of radiation-induced Sf9 apoptosis by miR-31 primarily through manipulation of Bim pathway, which is yet unknown in human/mammalian system and may be important for regulating cellular radioresistance. This knowledge may help in developing more effective strategies for modifying cellular radioresistance in higher eukaryotes/mammals.
Abstract ID 0183
Nuclear Factor-Kappa Beta/P53 Mediated Signaling Pathways Assisted the Recovery of Radiation Induced Gastrointestinal Injuries in Mice by Prophylactic Administration of a Combination of Podophyllotoxin and Rutin
Bhargab Kalita 1 , Rajiv Ranjan 1 , Sania Bajaj 1 , Manju L. Gupta 1
1 Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences, Brig.S.K Mazumdar Marg, Delhi 110054
Exposure to high doses of ionising radiation leads to the loss of regenerative potential of intestinal crypts and mucosal inflammation. The current study has been envisaged to explore the potential of a combination of podophyllotoxin and rutin (G-003M) in reducing radiation induced damage in mice gastro intestine (GI). C57/BL6 mice were exposed to lethal dose (9Gy) of γ-radiation. Activation of Nuclear factor-κB (NF-κB) and modulation of expression of COX-2, iNOS-2, Bax, BCl-2, p53, PUMA were detected by western blotting. Cytokines level was determined by flow cytometry. PGE2 levels in serum were determined by ELISA. Morphological changes in mice jejunum region were detected by histopathology. Apoptosis was analysed using AnnexinV-PI dual staining assay. Pre-treatment of mice with G-003M (-1 hr) markedly decreased the radiation induced activation of NF-ĸB expression (p<0.001) and also restricted its nuclear translocation by 3.5 fold (p<0.001). Formulation pre-treatment also negatively down regulated the expression of COX-2 (2.5 fold) and iNOS significantly (2 fold). Radiation induced ROS and nitric oxide (NO) generation in intestinal epithelial cells was found significantly (p<0.001) reduced by G-003M pre-treatment. G-003M suppressed radiation induced elevation of pro-inflammatory cytokines TNF-α, whereas IL-6 and G-CSF levels got elevated. Histological features of radiation induced GI damage were attenuated by regulated expression of Bax, Bcl2, p53 and PUMA protein. Our formulation has shown great potential in minimising radiation induced GI damage by regulating various pathways. Understanding the radioprotective and anti-inflammatory mechanism of G-003M is a crucial step in its development as a safe and effective radioprotective drug.
Abstract ID 0184
Connexins as Potential Targets for Modulating Low-Dose Radiation Responses in Tumour versus Normal Cells
Division of Natural Radiation Response Mechanisms, Institute of Nuclear Medicine and Allied Sciences, Delhi- 110054, India.
Low sub-lethal doses of radiation to tumour regions cause secondary malignancies, the mechanisms of which are not yet established. Studies indicated connexin upregulation by low doses while connexins are independently shown to alter cell migration in the unirradiated cells. We hence investigated low-dose gamma radiation induced alterations in connexin-43 (Cx43) expression and associated molecular pathways. A narrow range of low doses (10 cGy-20 cGy) enhanced Cx43 expression and also selectively induced tumour cell migration without altering cell proliferation. Low-dose induced cell migration and p38 activation was strongly inhibited by knocking down Cx43 expression. Silencing Cx43 caused near-complete inhibition of radiation-induced cell migration/invasion in tumour cells, whereas no cell migration/invasiveness was induced in the irradiated primary or transformed fibroblasts, thereby demonstrating regulatory role of connexins. We further evaluated the fate of tumour and normal cells in the event of silencing connexin-43 prior to irradiation at low doses. Asynchronously growing tumour cell cultures and normal fibroblasts were gamma-irradiated at varying doses, with a parallel asynchronous group subjected to Cx43-knockdown. Depletion of Cx43 by siRNA elicited HRS response, directly implicating Cx43 in this phenomenon. In the Cx43-depleted cells, low-dose irradiation also caused significant cell growth inhibition and cell death associated with Bax translocation. Therefore, downregulation of Cx43 renders tumour cells highly susceptible to low-dose HRS. Our study thus demonstrates that Cx43 mediates low-dose radiation induced cell migration selectively in tumour cells, and silencing it reverses this process and renders tumour cells hypersensitive to low doses. The study may have strong implications for therapeutics.
Abstract ID 0185
Radioprotective Activity of the Piper betle-derived Phenolic, Allylpyrocatechol against Gamma-Ray induced Hemolysis of Human Red Blood Cells
Meenakshi K 1 and S. Chattopadhyay 2
1 Dept. zoology, N.E.S, Ratnam College of Arts, Science and Commerce, N.E.S complex, NHS Marg, Bhandup (west), Mumbai - 400078, 2 Bio Science Group (B), Bhabha Atomic Research Center, Mumbai- 400 085
As an oxidative shuttle, human (RBCs) are most susceptible to oxidative damages leading to multiple diseases including haemolytic anemia that is a major public health problem in the developing countries. The present effort was aimed at formulating some natural phenolic compounds isolated from piper betle - allylpyrocatechol (APC) to prevent the alterations in the RBC membrane. The biochemical parameters which are considered as biomarkers of redox balance primarily contribute to damages in RBC membrane during gamma radiation induced oxidative stress were investigated. Compared to control gamma ray treatment with hypotonic stress resulted in significant haemolysis, associated with increased MDA (3.3 fold, p<0.001) and met- haemoglobin (7.0 fold, p<0.001). The structural deformation due to membrane damage was confirmed from SEM images and Heinz body formation, while the cell permeability was evident from the K+ efflux (32.4%, p<0.05) and increased intracellular Na+ concentration (5.3%, p<0.05). The membrane damage, due to the reduction of the cholesterol/ phospholipids ratio and depletion (p<0.001) of ATP, 2,3- DPG by 55.8% and Na+-K+ ATPase activity (47%) indicated loss of RBC functionally. Pre-treatment of the RBCs with APC (7 µM) or vitamin E (50 µM) for 1 h reversed these adverse effects of gamma radiation under hypotonic conditions on all these parameters and provided significant protection against oxidative haemolysis.
Abstract ID 0186
Beam Suppresses Metastatic and Cancer Stem Cell like Phenotype in Human Lung Carcinoma Cells as Compared to Equitoxic Dose of Gamma Radiation
Himanshi Narang 1 , Amit Kumar 2 , Nagesh Bhat 3 , Badri N. Pandey 2 and Anu Ghosh 1
1 Radiation Signaling Group, 2 Radiation Signaling and Cancer Biology Section; Radiation Biology and Health Sciences Division, 3 Radiological Physics and Advisory Division; Bhabha Atomic Research Centre, Mumbai, India -400085
The unique energy deposition profile of proton beam has made proton therapy a preferred modality over conventional radiotherapy. How does this unique energy deposition pattern translates at cellular level is largely unexplored. Here we investigated the effect of proton- and gamma- irradiation on various biological end points such as cytotoxicity, cell cycle arrest, gene expression, Epithelial-mesenchymal transition (EMT) and "stemness" in human non-small cell lung carcinoma cells (A549). Proton (3MeV) was found to be two times more toxic than equivalent dose of gamma radiation and also induced higher and longer cell cycle arrest (G2/M) as assessed by clonogenic assay and flow cytometry, respectively. Microarray study revealed that at equivalent doses, numbers of genes responsive to proton were higher than those responsive to gamma by a factor of ten. Adhesion, migration and invasiveness at both cellular and molecular levels were lower in proton irradiated cells as compared to gamma irradiated cells. At equitoxic doses, proton irradiation was also more effective in reducing population of CSC like cells as observed by aldehyde dehydrogenase activity and surface phenotyping. These results can have significant implications for proton therapy in context of higher cell killing and suppression of molecular and cellular processes that are fundamental to tumor expansion.
Abstract ID 0187
Evaluation of Micronucleus Assay In Vitro and In Vivo to Assess Radiation Genotoxicity
Kainat Khan 1 ,Shikha Tewari 1 ,S.P.Mishra 2 ,Madhup Rastogi 2 ,Nuzhat Husain 1
1 Department of Pathology, Dr Ram Manohar Lohia Institute of Medical Sciences,Lucknow, 2 Department of Radiation Oncology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow
Micronuclei may originate from acentric fragments (chromosome fragments lacking a centromere) or whole chromosomes which are unable to migrate with the rest of the chromosomes during the anaphase of cell division. The purpose of the micronucleus assay is to detect instability which modify chromosome structure and segregation is such a way as to lead to induction of micronuclei in interphase cells. This study uses micronucleus assay to detect radiation induced genotoxicity. An in-vitro study was planned where blood was irradiated using LINAC. The radiation dose irradiated with was 0 Gy, 0.10 Gy, 0.25 Gy, 0.50 Gy, 1 Gy and 2 Gy. A comparative study was done where genomic instability was detected using micronucleus assay in patients exposed to diagnostic (5) and therapeutic (5) ionising radiation and a control group with no exposure (5). The cells were cultured according to standardized protocol, stained in geimsa and visualized on Zeiss Microscope. 200 binucleate cells per sample were analysed for the presence of micronucleus. The micronuclei frequency increased in cells exposed to range of doses (0.1-2 Gy) delivered. The no exposure control showed minimal MN formation (2.0%±0.05) with almost triple MN (5.6%±2.0) frequency in lowest dose of 0.1 Gy. MN formation increased exponentially with the radiation dose thereafter and maximum micronuclei were counted at 2 Gy dose (28.5±0.4).Similar pattern was observed in the study including diagnostic and therapeutic radiation, where micronucleus frequency increased with increase in radiation dose. The in vitro assay demonstrated exponential increase of micronucleus with radiation doses. The assay when applied to low dose and high dose yielded concordant results. Thus micronucleus assay can be used to assess genotoxicity.
Abstract ID 0188
Trend on the Medical Sources of Radiation Exposures to the Population
Shangamithra V , Solomon FD Paul, Perumal Venkatachalam
Department of Human Genetics, Sri Ramachandra University, Porur, Chennai-600116
Ionizing radiation has been increasingly applied in the field of medicine and is firmly established as an essential tool for many disease/disorders. Such a wide application in medicine is due the inherent advantages like less invasive, cost and time factor. Nevertheless, it contributes more to the total effective dose to the public. In developed countries, the contribution from medical sources of radiation has become doubled (0.56 to 3 mSv/y within 2 decades); unfortunately, young individuals are also exposed. Among the procedure, imaging modality with X-rays (interventional radiology and computed tomography) are used frequently, where the contribution of the effective dose is maximum. Despite the advantages, an inherent dose to the patient is a major concern; this is because literature demonstrated a higher risk of developing stochastic effects. Therefore, we measured the patient dose using ThermoLuminiscent dosimeters (TLD) in individuals, who have been exposed to radiations during interventional radiological procedures.The overall measured doses ranged from 49.01-220.99 mSv for head 46.31-191.55 mSv for neck and shoulder was 7.83-155 mSv measured in patient undergoing cerebral angiography (n=50). The biological effect due to the radiation exposure is being quantified using CA, gamma H2AX and p53 Ser-15. The frequency of those changes will be correlated with the measured organ doses; the significance of the doses to that of biological effect received in the low dose radiation exposure will be discussed.
Abstract ID 0189
No Impact on P-gp Level in Radio-Resistant Mcf-7 Cells
Madhu LN 1 , Shama Rao 2 , Sarojini BK 3
1 PG Department of Biochemistry, St. Aloysius College, Mangalore; 2 K.S.Hegde Medical Academy, Nitte University, Mangalore; 3 Department of Industrial Chemistry, Mangalore University, Mangalore
Cancer has become the leading cause of human death worldwide. One possible cause for therapeutic failure is that residual tumor cells are reminiscent of stem cells, which ultimately give rise to secondary tumors or distant metastasis. The property of resistance to radiation therapy or chemotherapy might be the major clinical criterion to characterize "cancer stem cells (CSCs)". In the process of radiotherapy, the radiosensitive cancer will become a radio-resistant one. Such radio-resistance cells might also show the characters of multi drug resistance (MRD) properties which may affect the chemotherapy process. The present study was carried out to know the expression level of P-gp, a MRD protein in radio-resistance breast cancer cells. The study conducted by exposing the MCF-7 cells to 4Gy of gamma radiation. The percentage of viability by MTT assay and Apoptotic cell percentage using EB/AO staining was performed. Bcl-2, a anti apoptotic protein level was estimated using ELISA and Western blotting to characterize the resistance property. P-gp expression level was studied in the irradiated cells using RTqPCR and it was compared with the control group. 18sRNA was used as a reference gene for the RTqPCR analysis. 4Gy irradiated group of MCF-7 cells showed 50 percent reduction in the cell viability also there was elevation found in the apoptotic cell percentage. 4Gy gamma radiation survived cells after one passage showed significantly (P<0.05) increased level of Bcl-2 protein, which concludes the resistance property of the cells. But there was no expression of P-gp upto 50 cycles when compared to the control group (32.54). This result concludes that, the radio-resistant cells do not show any character of MDR cells.
Abstract ID 0190
Off-site Radiological Impact of Postulated Accident Scenarios in Special Vault of Near Surface Storage and Disposal Facility at Kalpakkam
Arti S. Mhatre 1 , Chitra S. 1 , Kapil Deo Singh 1 , V.K.Sharma 2 , K. Banerjee 3 , C.K. Chakrabarti 4
1 Health Physics Division, 2 Ex-BARC, 3 Nuclear Recycle Group 4 Fast Reactor Waste Management Directorate, Bhabha Atomic Research Centre, Mumbai-85
The Waste Management Facility (WMF) at Kalpakkam is a fuel cycle back-end facility designed for treatment, conditioning and storage/disposal of radioactive waste generated from various plantsof Fast Reactor Fuel Cycle Facility (FRFCF). The WMF comprises i) a Waste Management Plant (WMP) ii) an Annexe building (Solid Waste Treatment Plant), and iii) the Near Surface Storage and Disposal Facility (NSSDF). The NSSDF comprises Special Vault, Alpha Storage Facility (vault/ container), Stone-lined trenches, RCC trenches, and Tile holes. The SV will be used for above-ground building storage of PFBR fuel hardware components mainly comprise top and bottom cut portion of fuel with contact dose rate > 30 Gy/h (Category III non-alpha solid waste, > 0.5 Gy/h). The high surface dose rate of the waste will be due to activation products like 60 Co, 54 Mn, etc. This paper presents a study on off-site radiological impact of postulated accident scenarios in Special Vault of the NSSDF. Two variants(stack level and ground level release)of the most significant scenario in which the crane fails while transferring drum from vehicle to SV followed by fall of the drum have been quantified for source term and off-site dose. Dose from 60 Co and 54 Mn and all relevant pathways (Plume-shine, Inhalation, Ingestion, and Ground-shine) is included. Site-specific meteorological data is used for dose computation. For the NSSDF, a passive stack of 75m height is assumed for elevated releases. The total radioactive inventory in SV would be 3.36E+6 Ci. This activity has been calculated based on the design dose rate on the surface of the waste drum. Off-Site atmospheric dose at 500 m for this scenario for stack level release is 1.50E-7 Sv while that for ground level release is 1.17E-04 Sv. The accident doses are well within the regulatory design dose targets.
Abstract ID 0191
Dietary Polyunsaturated Fatty Acid Supplementation Ameliorates the Ionizing Radiation Induced Cognitive Deterioration
Mahesh Bekal 1 , Suchetha Kumari 2
1 Department of Biochemistry, Kanachur Institute of Medical Sciences, Mangalore., 2 Department of Biochemistry, K.S.Hegde Medical Academy, Mangalore.
The whole brain irradiation causes injury to the nervous system at various levels. Omega-3 Poly Unsaturated Fatty Acids are very much essential for the growth and development of nervous system. Dietary supplementation of these nutrients will promote the development of injured neuronal cells. Therefore, this study was undertaken to establish the role of Omega-3 Poly Unsaturated Fatty Acids on Memory, Learning ability and anxiety levels in the irradiated mice. The effect of Electron Beam Radiation (EBR) on memory and learning ability was investigated in male Swiss albino mice. The study groups were subjected to a sub-lethal dose of 8 and 6 Gy of EBR and also the Fish oil and Flax seed extract (300 mg/kg body weight) were given orally to the irradiated mice. After 24 hours exposure, the memory and learning ability of mice were evaluated using the Lashley III maze. From the experiments on irradiated mice, we have found evidence to suggest cognitive deterioration in the initial days of task performance. The control groups learned the maze in 5.2 (±1.5) days. By contrast, the irradiated animals took 11.7 (± 2.1) days to reach criterion. Whereas the PUFA supplemented groups were able to learn the task 7.4 to 8.7 days. In the test for learning ability, irradiated group required significantly (p>0.01) more time to complete the task when compared to that of the control group (Control 1.8± 0.59, Radiation 29±4, Flax Seed 11±5.9, Fish Oil 13±6.4 seconds), indicating the radiation induced tissue damage at the hippocampal region of the brain. Similar effects were observed on the memory power of the irradiated groups, measured by the number of errors committed during the task. Both control and irradiated groups showed a steady increase in the learning index from trials 2 through 4. The experimental data suggests cognitive deterioration in initial days of the task performance compared to the control groups, indicating the acute radiation effects on the central nervous system. The dietary PUFA supplemented groups performed the task at a higher rate than that of the irradiated groups indicating a significant improvement in performance of irradiated groups. This study suggests that the dietary intake of PUFAs may help in prevention and recovery of neurological damage caused by radiation.
Abstract ID 0193
Kerma for Amino Acids
C. V. More 1 and R. R. Bhosale 2 , R. M. Lokhande 3 , S. V. Doifode 4 P. P. Pawar 5
1 Author's Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004
The gamma ray photon interactions with the amino acids have been discussed mainly in terms of mass attenuation coefficients (mm ), mass energy absorption coefficients (µ en/r) and kerma relative to air (K air ) in the energy range 0.01-15 MeV. L-thioproline (C 4 H 7 NO 2 S) and L-cystine (C 6 H 12 N 2 O 4 S 2 ) are the amino acids under investigation. Since direct measurements are difficult, theoretical computations are used. In this paper, analytical equations are employed to determine these parameters. With the increase in energy, mm values decrease. µ en/r and K air values initially decrease with increase in energy from 0.01 MeV to 0.1 MeV then increase with increase in energy up to 3 MeV and again start to decrease up to 15 MeV for both the samples. The increase and decrease in parameters depends upon the gamma ray photon interactions with matter viz. photoelectric effect, Compton scattering and pair production. These parameters have been widely used for problems and applications involving dose calculations.
Abstract ID 0194
A New Radiation Biology: Epigenetics, Exosomes and Metabolism
M.J.Atkinson 1, 2
1 Institute of Radiation Biology, Helmholtz Zentrum Munich, Germany; 2 Chair of Radiation Biology, Technical University of Munich, Germany
Exposure to ionizing radiation leads to chronic disease, including cancer, cardiovascular disease, neurocognitive deficits and possibly metabolic diseases. The prevailing paradigm of radiation biology considers DNA damage to be the initiating event. Misrepair of initial DNA damage leads to gene mutations that promote clonal expansion and eventually malignancy. However, the paradigm is inconsistent with some recent radiobiological observations. The probability of a cancer-relevant mutation arising in a critical gene is far too low to explain the frequency of induced cancers, nor do these cancers show mutation fingerprints consistent with an initial damage event and clonal expansion. Direct targeting of critical genes is inconsistent with possible mechanisms of non-targeted effects. Finally, non-cancer effects do not show or require clonal expansion or DNA mutation. In view of these challenges to the paradigm, we have investigated the effects of radiation without prejudice. These studies have led to a unifying model of radiation action that may be applied to both non-cancer and cancer effects. We have identified a radiation damage response involving persistent alterations in mitochondrial function, release of biologically active exosomes, and alterations in epigenetic control of cell function. These act together to reset the cellular phenotype after irradiation. These changes may be the cause or consequence of the formation of reactive species. They may be the underlying cause of gene mutations observed in cancer and the physiological changes in non-cancer diseases.
Supported by grants from the European Community (EURATOM) contracts 295552 (CEREBRAD), 295823 (PROCARDIO), 323216 (Dark.Risk) and 249689 (DoReMi).
Abstract ID 0197
Performance Analysis of Flat Panel Detector of Panacea Imagin Radiotherapy Simulator using Leeds test Object TOR IQ II Phantom
Priyanka Agarwal 1 , Ashish Binjola 1 , Seema Sharma 1 , Megha Singh 1 , V. Subramani 1 , Subhash Chander 1 , G. K. Rath 1
1 Department of Radiotherapy, DR. B. R. A. IRCH, AIIMS, New Delhi - 110 029
In our Department, radiotherapy (RT) simulator is mainly used for pre-treatment patient setup verification before three dimensional conformal radiotherapy (3D-CRT)/intensity modulated radiotherapy (IMRT) and for conventional patient planning of palliative and simple curative treatments. After decommissioning of our old RT simulator, a new RT Simulator (Imagin, Panacea Medical Systems, Bangalore) was installed. This is the first piece of the RT simulator which has functional cone beam computed tomography (CBCT) scanner. Acceptance testing and commissioning of this RT simulator was done using AERB guidelines. As a part of these tests, image quality performance test of its flat panel detector was performed using Leeds Test Object TOR IQ II phantom because the image quality performance of RT simulator is necessary for verifying the accuracy of planned treatment. Using this test tool, isocentre test, spatial resolution (low contrast sensitivity, high contrast sensitivity) and image uniformity has been analyzed during commissioning. Analysis of the test results shows that isocentre is within 2 mm diameter circle (Tolerance ≤ 2 mm). In the case of low contrast sensitivity test, 0.6 mm diameter hole was clearly visible in Leeds test object (tolerance: hole of diameter 1/8" must be clearly seen). High contrast sensitivity was 3.1 lp/mm (tolerance 1.6 lp/mm). Uniformity of image was within the specified tolerance. As all above image quality tests are within tolerance limit, RT Simulator flat panel detector is clinically accepted.
Abstract ID 0198
Standardization of Calyculin-A Induced Premature Chromosome Condensation Assay and its Advantages Over Okadaic Acid Premature Chromosome Condensation Assay in Biodosimetry Applications
Rajesha K Nairy *1 , Nagesh N Bhat 2 , Ganesh Sanjeev 3 and Narayana Yerol 3
1 Department of Physics, P.A college of Engineering, Mangalore-574 153;2 RP and AD, Bhabha Atomic Research Center, Mumbai-400 085. 3 Depatment of studies in Physics, Mangalore University, Mangalagangotri-574 199
In the present study, an attempt was made to estimate coefficients of dose response curves for three PCC aberrations induced by Calyculin-A and Okadaic acid, using 60 Co-gamma and 8 MeV pulsed electron beam for biodosimetry application. The modified method outlined by Roser Puig et al. 2013 was used to conduct Calyculin-A and Okadaic acid induced PCC assay in human blood lymphocytes. Chemical treatment was given for last 1 hr of the 48 hr culture. The study was carried out in the dose range 2.5-20 Gy using 60 Co gamma rays. Results show a linear dose dependent increase with a slope of 0.0479 ± 0.001 from Calycalin A PCC and 0.049 ± 0.002 form Okadaic acid PCC. The slope of the fragments curve was 0.31 ± 0.017 from Calyculin A and 0.32 ± 0.012 from Okadaic acid PCC. Further dose calibration studies were carried out for 8 MeV electron using Calyculin A PCC assay and the obtained slope from rings yield was found to be 0.06 ± 3×10 -3 and 0.33 ± 6×10 -3 from fragments yield. The present study reveals that the calyculin-A and Okadaic acid induces similar rings and fragments yield. But PCC spreads percentage is higher in Calyculin-A PCC assay, which is an important parameter in case of biodosimetry application. Dose calibration studies confirm that the rings and fragments yield increases linearly with the doses and slightly higher yields were obtained for 8 MeV pulsed electron beam compared to gamma radiation.
Abstract ID 0199
Detection of New Polymer Materials as Gamma Ray Shielding Material
R.R. Bhosale 1 , D.K. Gaikwad 2 , V.V. Awasarmol 3 , C.V. More 4 , P.S. Kore 5 , P.P. Pawar 6 , M.N. Rode 7 *
1, 2, 3, 4, 5,6 Department of Physics, Dr.Babasaheb Ambedkar Marathwada University, Aurangabad-431004, India. 7* Department of Physics, Vaidyanath College, Parli-Vaijnath, Dist.Beed-431515, India
Mass attenuation coefficient (µ m ), effective atomic numbers (Z eff ), electron densities (N eff), total cross-section (σt) and electronic cross-section (σe ) have been computed for polymers Polyoxymethylene (CH 2 O), Polyacrylonitrile (C 3 H 3 N), and Polyethyl acrylate (C 5 H 8 O 2 ) using narrow beam good geometry set-up. In the present work, radioisotopes 57 C O , 133 Ba, 137 Bs, 54 Mn, 60 C O and 22 Na emitting energies 122, 356, 511, 662, 840, 1170, 1275 and 1330 keV have been counted by a NaI (Tl) detector coupled with the 8 K multichannel analyzer. Results of µ m, σt, σe decreases with increasing energy of gamma photons due to the dominance of Compton scattering in the present energy range. Effective atomic numbers of chosen samples tend to be almost constant as a function of energy. Similarly, Effective electron densities of polymers are found almost constant in the range of 0.323×10 23 - 0.321×10 23 /gm. It is clearly observed from the computed results that the chosen polymer samples have good absorption capability of gamma photons in low energy region. We believe that some high Z elements dope with polymers may have potential applications in the shielding of high energy gamma photons. An attempt has been made to investigate the new gamma ray shielding materials that can be used at large scale and available at low cost.
Abstract ID 0203
Occupational Radiation Exposure Status in Nepal
Buddha R Shah and Gita Chalise
Faculty of Science, Nepal Academy of Science and Technology, GPO 3323 Kathmandu Nepal
The use of ionizing radiation and the practice of medicine in diagnosis and treatment of diseases have been revolutionized benefitting the humankind and at the same time imposing deleterious health effects if not handled carefully. In the context of Nepal, most hospitals use X-rays in many forms for imaging inside of the body but least are found to be concerned about personnel as well as area monitoring. Nepal Academy of Science and Technology (NAST) has recently initiated personnel dosimetry service in the country. In this work, health personnel working in radiation sectors at eight different hospitals have been monitored under a pilot study during their routine work using Thermoluminescence Dosimetry (TLD). The TLD cards exposed for specified period were read out with semi-automatic TLD badge reader (TL1010A,Nucleonix, India). For the examination procedures like general X-ray, CT scan and mammography where radiation workers do not have to get direct radiation exposure, in such procedures the result for exposure rate of individual staff monitored was found in the minimum range from 2.21±0.01mSv per year to maximum range 16.17±0.01 mSv per year whereas absorbed dose rate with minimum and maximum range was 1.57±0.01 mSv per year and 11.48±0.01 mSv per year, respectively. However, including the fluoroscopic examination in which the workers get direct exposure, the absorbed dose rate for health personnel in those hospitals during their routine work was found in the range of 1.57-15.66 ± 0.01 mSv per year whereas the exposure dose was found in the range of 2.21-22.06 ± 0.01 mSv per year. In addition, the absorbed dose and exposure dose values obtained for individual personnel have been compared with the diagnostic reference level set by the International Commission On Radioological Protection (ICRP).
Abstract ID 0205
Emerging Trends in Actinide Radiobiology: From Mechanisms to Mitigation Strategies
Amit Kumar , Manjoor Ali and Badri N. Pandey
Radiation Signaling and Cancer Biology Section, Radiation Biology and Health Sciences, Division, Bhabha Atomic Research Centre, Mumbai 400 085
In the field of 'Radiation Biology' significant efforts are being made to understand the mechanisms of biological effects that are resulting from the external irradiation of cells/animals. However, entry of radioactive material itself (actinides and lighter elements) in human may occur during occupational/accidental scenarios. These internalized radionuclides cause serious health consequences due to their radiological and chemical interactions, which have not been investigated to that extent, at cellular and molecular level. This talk would present the results on the mechanisms of biological effects of actinides mainly Thorium-232 (alpha-emitter) and the potential of novel decorporation strategies. Our study identified glycophorin, as a target of 232 Th effects on human erythrocyte. Animal studies demonstrated liver and bone as the major depository organs of 232 Th, causing oxidative stress by altering superoxide dismutase/catalase. Liver microarray revealed the potential of serum amyloid protein A as a biomarker of 232 Th toxicity. Results showed the key role of IGF1R in 232 Th-induced proliferative effect in liver cell (HepG2). Effect of 232 Th in combination with alpha radiation was found to enhance DNA damage response. These results have significant relevance in understanding the mechanism of Th-induced liver carcinogenesis. 232 Th was also observed to cross the blood-brain barrier in mice. A molecular basis of interaction of Th, U and other relevant metals with human blood proteins (hemoglobin and albumin) was elucidated. The potential of liposomal-DTPA and other non-toxic formulations for actinide decorporation would be presented. These results significantly advanced our understanding of actinide toxicity and development of efficient approaches for the mitigation of their radiological/chemical toxicity. As a function of incident photon energy. The variations of above quantities for photon interaction with energy are shown graphically and comparison between them within good agreement.
Abstract ID 0207
Studies on Attenuation Coefficient of Some Vitamins in the Energy Range 122 to 1330 keV
U. S. Rajurkar 1 , P. S. Kore 2 , R.R.Bhosale 3 and P. P. Pawar 4
1, 2, 4 Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad: 431 004, (M.S); 3 Vaidyanath college,Parli-V.,Beed-431515,(M.S) India.
In this research work we focused to evaluate some attenuation parameters; mass attenuation coefficient (mm ) and total atomic cross sections (stot) and molar extinction coefficient (ε) of four Vitamins viz., Niacin (C5 H 5 NO 2 ), Adenine (C 5 H 5 N 5 ), Para Aminobenzoic Acid (C 7 H 7 NO 2 ) and Pyridoxine (C 6 H 11 NO 3 ) were computed for gamma active sources Cr 52 , Zn 65 , I 131 , Eu 152 , Hg 203 for the energy range of 122 keV to 1408 keV are used in this study which are mostly useful in medical and health physics. Variation of these parameters has been studied as a function of incident photon energy. Many of vitamins have infamous food processing and some have important therapeutics for clinical use of drugs such as niacin that helps maintain healthy skin and nerves. It is also has cholesterol-lowering effects. Adenine is one of the two purine nucleobases (the other being guanine) used in forming nucleotides of the nucleic acids. Many of which have important industrial applications in the food and pharmaceutical industries. The gamma rays were detected by using an NaI(TI) scintillation detector. The measured values and computed values obtained by Win X-com. Variation of these parameters have been studied.
Abstract ID 0210
Study of Radon, Thoron, Attached/Unattached Progeny, Unattached Fractions, Equilibrium Factors and the Radiation Doses in the Indoor Environment of Garhwal Himalaya
Mukesh Prasad 1 , Anik Rudra 1 , Tushar Kandari 1 , Preeti Pant 1 , Peter Bossew 2 , Rosaline Mishra 3 and R.C. Ramola 1
1 Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal - 249 199, India; 2 German Federal Office for Radiation Protection, Berlin, Germany; 3 Radiological Physics and Advisory Division, Bhabha Atomic Research Centre Mumbai - 400 085, India
The annual exposure to indoor radon, thoron and their progeny imparts a major contribution to inhalation dose received by the public. In this study, we report the time integrated passive measurements of indoor radon, thoron and their attached and unattached progeny concentrations that were carried out in Garhwal Himalaya with the aim of investigating whether the exposure to these nuclei involves significant health risk to the dwellers of the investigated region. The experimentally determined values of radon, thoron and their progeny concentrations were used to estimate thetotal annual inhalation dose, annual effective doses and equilibrium factors. The attached and unattached progeny fractions are found positively correlated, although only weakly, with Pearson correlations R = 0.28 and 0.31, for radon and thoron, respectively (significant with p < 0.01 in both cases).The estimated values of equilibrium factors for radon and its progeny and for thoron and its progeny were found to be 0.42 and 0.07, respectively.The estimated value of total annual inhalation dose due to the exposure of radon, thoron and progeny was found to vary from 0.8 mSv/y to 4.6 mSv/y with an average of 1.8 ±0.7 mSv/y. The estimated values of annual effective doses from the exposure to radon and its progeny and from the exposure to thoron and its progeny were found to vary from 0.5 mSv/h to 3.1 mSv/h with an average of 1.2 ± 0.5 mSv/y and from 0.2 mSv/h to 1.3 mSv/h with an average of 0.5 ± 0.3 mSv/y, respectively.The estimated values of radiation doses have shown no significant health risk due to exposure of radon, thoron and progeny in the study area. Moreover, the contribution of indoor thoron and its progeny to the total inhalation dose ranges between 13%-52% with the mean value of 30%. Thus, thoron cannot be neglected when assessing radiation doses.
Abstract ID 0213
A Non Classical Bacterial DNA Damage Response in Radioresistant Bacterium Deinococcus radiodurans
Y. S Rajpurohit, N. P. Khairnar, H. S. Misra
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai-400085
Deinococcus radiodurans is best known for its extraordinary resistance to γ radiation (with its D10 ~12kGy), several other DNA damaging agents, dessication to less than ~5% humidity and chemical toxicants. An efficient DNA double strand break (DSB) repair and its ability to protect biomolecules from oxidative damage are the few mechanisms attributed to these phenotypes in this bacterium. Although it regulates the levels of its proteome and transcriptome in response to DNA damage, it lacks LexA mediated classical SOS response mechanism. Since LexA mediated damages response mechanism is highly and perhaps only, characterized DNA damage response processes in prokaryotes, this bacterium keeps us guessing how it responds to extreme doses of DNA damage. Interestingly, we noted a large number of eukaryotic type serine /threonine/tyrosine protein kinases (eST/YPK), phosphatases and response regulators in its genome, and the roles of eST/YPKs in cellular response to DNA damage and cell cycle regulations are well established in eukaryotes. Catching the tail of an antioxidant, we characterized an antioxidant and DNA damage inducible eST/YPK (RqkA) and established its role in extraordinary radioresistance and DSB repair of this bacterium. We identified native phosphoprotein substrates for this kinase and demonstrated the involvement of some of these proteins phosphorylation in the regulation of DSB repair and growth under radiation stress. Findings suggesting the possible existence of eST/YPK mediated DNA damage response mechanism as an alternate to the classical SOS response would be discussed.
Abstract ID 0214
Theranostic Radiopharmaceuticals: A Pathway Towards the Personalized Medicine
Radiopharmaceuticals Chemistry Section, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India
The term 'Theranostic' refers to the two interdependent applications, namely diagnosis and therapy, using the same agent. In 'Nuclear Medicine', 'Theranostic' implies diagnosis and therapy of a particular disease using the same radiopharmaceutical. Since in this case, pre-therapy information can be directly utilized to tailor the high-dose therapy for a specific patient, its helps in the realization of the so called 'Personalized Medicine'. The concept of 'Theranosis' can be achieved in three distinct ways - by using the different radioisotopes of the same element (e.g. 123 I and 131 I) or by using a matched pair of radionuclides (e.g. 99m Tc and 188 Re), but perhaps the best way is to use the dual purpose radionuclides i.e. particulate emitters having accompanying gamma emission (e.g. 177 Lu, 166 Ho, 153 Sm, 188 Re etc.).
In the past few years, persistent efforts undertaken at BARC have lead to the development of several promising 'Theranostic Radiopharmaceuticals', a few of which have successfully reached clinical domain. It is observed that 177 Lu-DOTA-TATE, which is used for providing radiotherapeutic treatment to various kinds of neuroendocrine cancers, can administered in low-dose for the diagnosis of the disease; as it picked up the same lesions observed with 68 Ga-DOTA-NOC. Similarly, striking similarity observed between the post-therapy scans obtained with 177 Lu-EDTMP and 99m Tc-MDP in patients, suffering from skeletal metastases, indicate the possibility of using low-dose preparation of 177 Lu-EDTMP for the diagnostic imaging of such patients. The possibility of clinical utilization of such agents for both diagnosis and therapy paves the way towards the realization of the goal of 'Personalized Medicine'.
A0 bstract I0 D 0215
0 Proteomic and Transcriptomic Profiling of In Vitro Established Radiation Resistant Oral Cancer Cells for Identification of Radioresistance Related Biomarkers
Mohd Yasser, Sagar Pawar , Tanuja Teni
Teni Lab, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar Node, Navi Mumbai-INDIA.
Radiotherapy is an integral part of oral cancer treatment, either alone or in combination with surgery. But, during radiotherapy, oral tumours of a subset of patients develop radioresistance that creates major obstruction towards its efficacy. The aim of our study was to establish radioresistant cell lines from different oral subsites using clinically admissible low dose radiation and profile them by proteomic and transcriptomic approaches to identify proteins associated with radioresistance in oral cancer. We have established three radioresistant oral cancer cell lines; 70Gy-AW13516, 70Gy-AW8507 (Tongue-SCC) and 70Gy-SCC029B (Buccal-SCC). Radiation was given in 2Gy dose by 60Co-γ irradiator (Bhabhatron-2) up to total dose of 70Gy to each and radioresistant character was assessed by clonogenic assay. Proteomic profiling of parental/resistant cells was done by 2D-gel electrophoresis. Gels were analysed by PD-Quest software and differential spot identities revealed by MALDI-TOF/TOF. To explore changes at transcript levels; cDNA microarray was performed by Affymetirx Gene Chip array and analysed by Gene Spring GX-12.5. MS identified 106 differential proteins among three parental/radioresistant cell lines with significant MS/MS score. A panel of 8 common proteins across three sets; GRP78, STIP1, PGP, PKM2, GRP94, PDIA3, HSP70-1A/B and HSPA8 were selected and validated by Real time-PCR. Further, statistically significant genes (>3 fold) from radioresistant cells of different sub sites (Tongue and Buccal) were mapped by David and Panther functional tools. Pathway analysis revealed genes related to altered cell survival and apoptosis pathways like; Apoptosis signalling, PI3K, P38 and Wnt signalling. Proteomic and transcriptomic profiling of established oral radioresistant cells may provide new insight in understanding mechanism underlying clinical radioresistance and help in identifying radioresistance related biomarkers.
Abstract ID 0216
Cell Cycle Phase Specific Chromatin Structures Differentially Influence DNA Damage Response Signalling to Ionizing Radiation
Epigenetics and Chromatin Biology Group, Gupta Lab., Cancer Research Institute, Advanced Centre for Treatment Research and Education in Cancer, Tata Memorial Centre, Kharghar, Navi Mumbai 410210, India.
Ionizing radiation (IR) induces DNA double-stand breaks (DSB) which are among the most severe lesions that can occur in a cell. Inefficient repair of DSB can cause cell death or lead to uncontrolled proliferation. Recently, alterations of epigenetic information, such as histone modifications, are observed following DNA damage, but its impact on cell cycle phase specific DNA damage response (DDR) signalling is less well understood. During the presentation we will discuss the importance of cell cycle phases on histone modification(s) and cell survival in response to IR-induced DNA damage on human liver cells. Our data shows G1-phase specific decrease of H3 serine10 phosphorylation (H3Ser10P) in response to DNA damage is coupled with chromatin compaction in repair phase of DDR. The loss of H3Ser10P during DNA damage shows an inverse correlation with gain of γH2AX from a same mono-nucleosome in a dose-dependent manner. Further, the loss of H3Ser10P is a universal phenomenon as it is independent of origin of cell lines and nature of genotoxic agents in G1 phase cells. Interestingly, the reversible reduction of H3Ser10P is mediated by opposing activities of phosphatase, MKP1 and kinase, MSK1 of the MAP kinase pathway. Moreover, blocking of H3S10 dephosphorylation by MKP1 inhibition impairs DNA repair process and results in poor survival of cells. The molecular mechanism elucidated in this study may provide insight into the design of future combination cancer therapies to G1 cells that are intrinsically more resistant to radiation therapy.
Abstract ID 0217
Targeting Homologous Recombination Pathway Radio-Sensitizes Werner-Helicase Deficient Cancer Cells
B.S. Patro 1 , Pooja Gupta 1 , Bhaskar Saha 1 and Subrata Chattopadhyay 1
1 Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Ionizing radiation (IR) induced DNA double-strand breaks (DSBs) are primarily repaired by non-homologous end joining (NHEJ) while a subset DSBs which are accumulated in G2 phase are repaired by homologous recombination (HR). DNA repair-deficient tumor cells have been shown to accumulate high levels of DNA damage. Consequently, these cells become hyper-dependent on DNA damage response pathways, including the CHK1-kinase-mediated HR-repair. These observations suggest that DNA repair-deficient tumors should exhibit increased radio-sensitivity under HR-inhibition. Genetic defects leading to functional loss of Werner (WRN) protein is associated with genomic instability and increased cancer incidence. In the current investigation, using isogenic pairs of cell lines differing only in the WRN-function, we showed that WRN-deficient cell lines were hyper-radiosensitive to CHK1 pharmacologic inhibition. Here, we found that unrepaired DSB was drastically increased in WRN-deficient cells vis-ΰ-vis WRN-proficient cells in response to IR and CHK1 inhibitor (CHK1i). Our results revealed a marginal role of NHEJ pathway accountable for the radio-sensitivity of WRN-deficient cells. Interestingly, silencing CTIP, a HR-protein required for RAD51 loading, significantly abrogated the CHK1i-mediated radio-sensitivity in WRN-deficient cells. Silencing of WRN or CTIP individually led to no significant difference in the extent of DNA end resection, as required during HR pathway. Imperatively, our results revealed that WRN and CTIP together play a complementary role in executing DNA end resection during HR-mediated repair of IR-induced DSBs. Altogether, our data indicated that inhibition of IR-induced HR pathway at RAD51 loading, but not at DSB end resection, make the WRN-deficient cancer cells to become hyper-radiosensitive.
Abstract ID 0218
Studies on Level of Cytokines and Expression of Connexin43 in Tumor and Normal Cells in Culture Conditions
V. Asati 1 and B. N. Pandey 2
1 Department of Biological Sciences, Birla Institute of Technology and Sciences, Pilani; 2 Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085
Factors secreted from the tumor cells in culture medium have been known to facilitate the growth of fresh cultures and also to affect the cellular radio-sensitivity. Moreover, expression of gap junction proteins like connexin-43 is known as a key player in cell survival and proliferation. The present study is aimed to evaluate the effects of conditioned medium on the growth of respective tumor/normal cells and the expression of connexin-43 in these cells. These parameters were studied in cancer cell lines of different origin i.e. breast (MCF-7), lung (A549), human fibrosarcoma (HT1080), mouse fibrosarcoma (WEHI164) and normal human intestine epithelial cells (INT407). The conditioned medium from these cells were analysed for presence of different soluble factors like IL-6, IL-8 and IL-1beta and vascular endothelial growth factor (VEGF) by ELISA method. Clonogenic assays showed higher plating efficiency (5-30 %) of cells cultured in respective conditioned media depending on cell types, which was related with the level of soluble factors in the conditioned medium. Moreover, the expression of connexin-43 in these cells was also studied by Western blotting. Higher level of connexin-43 was observed in HT1080, WEHI164 and INT407 but was lower in case of A549 and MCF-7 cells. The poor association between level of secretable factors and connexin43 expression suggest that their independent role in survival/proliferation depending on origin and nature of cells.
Abstract ID 0220
MeV Proton/Alpha Particle Ion MICRO-PROBE Facility at Institute of Physics
B. Rout 1,2 , S. Ram 1 ,D. K. Ray 1 ,J. B. M. Krishna 3 , and P. V. Satyam 1
1 Institute of Physics, Bhubaneswar-751005, India, 2 Department of Physics, University of North Texas, Denton, TX 76203, USA
MeV Ion microbeam facility was developed at Institute of Physics, Bhubaneswar in year 1998 . Due to some technical issues, this facility was not utilized for last one decade. The same facility has now again been revived. We plan to have dedicated radiation biology experiments at this beam line in very near future.The experimental capabilities of the present ion micro-beam facility includes (a) spatial resolution of ~10 microns using 3.0 MeV proton beams (developmental goal ~3 micron, which was achieved as in year 2001 with both proton and helium beam) (b) beam current up to 80 pA, (c) computer controlled X-Y stepper stage for the movement of the sample with 0.5 micron resolution. (d) PIXE and Elemental maps (e) beam scanning. To obtain beam of few microns diameter, the accelerated ion beam is reduced to ~100 micron in size using micro-polished slit assembly followed by focusing of the beam spot size with the help of powerful magnetic quadrupole doublet with ME/q2~16. The micro-quad lenses along with sample chamber are mounted on a vibration free table at the end of the beamline. A map with Cu K lines of a 200 mesh grid is show below. The images showed variation in wall thickness of different grids depending on the mesh size. The prospective applications have a wide range i.e. in the field fields of semiconductor, material research, archaeology, climate change and environmental science. Another potential field of application is radiation biology in general.
Abstract ID 0221
Biodosimetry Techniques For Regulatory Requirements and Radiological Emergencies
Nagesh N. Bhat
Radiation Biophysics and Bio-Dosimetry Group, Environmental and Bio-Dosimetry Section, Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai -4000085
Biodosimetry assays are performed to quantify and confirm genuineness of suspected and accidental over-exposure of ionizing radiation. Biodosimetry is the only way to estimate dose in most over-exposure scenarios as precise physical dose information are rarely available. Specificity to radiation, sensitivity, reproducibility, throughput, retrospective analysis, ability to distinguish non-uniform exposure, quick estimation, non-invasive and easy to perform are the ideal expectations. Biodosimetry lab of BARC has established techniques required to address the needs of various over-exposure scenarios. Dicentric chromosomal aberration (DCA) assay is being used as the gold standard of biodosimetry in the range of 0.1-5 Gy. Very high specificity to radiation, stability over several months and very low background has made this assay very useful for both regulatory requirements and radiological emergency situations. Techniques to meet special requirements are, fluorescene in situ hybridization (FISH) for retrospective biodosimetry, micronucleus assay as supplementary technique and premature chromosome condensation (PCC) assay by Okadaic acid, Calyculin-A and by mitotic fusion with metaphase Chinese hamster ovary cells for quick dose assessment. Gamma H2AX assay is also established which is helpful when blood samples can be collected within short time after exposure. Response curves for all these assays are established by ex vivo irradiation of blood samples from multiple donors. An SoP was developed for the analysis of blood samples collected at remote places and transported through commercial courier. Many automated facilities are in place few of which are indigenously developed facilities to achieve throughput, quality preparations and reduce manual interventions.
Abstract ID 0222
Perturbation of Cellular Redox Status using Pro-oxidants as an Effective Strategy to Kill Lymphoma Cells and Mitigate Ionizing Radiation Induced Normal Tissue Injury In Vivo
Radiation Biology and Health Sciences Division, Bioscience Group, Bhabha Atomic Research Centre, Mumbai 400094
Maintaining cellular redox homeostasis is crucial for the survival and normal functioning of cells. Cellular redox homeostasis can be disrupted by oxidative stress, ionizing radiation, xenobiotics and during cancer. Using plumbagin, a pro-oxidant, we show that modulation of cellular redox status can serve as an effective strategy for killing tumor cells and also for mitigation of radiation induced normal tissue toxicity. Plumbagin induced apoptosis in both murine and human T-cell lymphoma cells via increased oxidative stress, caspase activity and loss of mitochondrial membrane-potential. The pro-oxidant and cytotoxic effects of plumbagin were sensitive to antioxidants indicating a decisive role of cellular redox. Exposure of lymphoma cells to plumbagin led to inhibition of total and specific phosphatase activity, increased total protein S-glutathionylation and induced glutathionylation of dual specific phosphatase-1and4 (MKP-1 and MKP-2). The in vivo anti-tumor efficacy of plumbagin was demonstrated using a mouse model. On the contrary, plumbagin prevented radiation-induced apoptosis in normal lymphocytes. The radioprotective effects of plumbagin were reversed by thiol antioxidants and not by non-thiol antioxidants. We found that plumbagin physically bind to GSH and activates pro-survival transcription factor Nrf-2 and its dependent anti-oxidant genes (HO-1, GCLC, TrxR, catalase, MnSOD and NQO-1). The radioprotective effects of plumbagin were reversed by Nrf2 inhibitor ATRA and HO-1 inhibitor SnPP. The "blind docking" showed that plumbagin has an affinity to bind to the active site pocket of caspase. These results show underscore possible application of plumbagin for treatment of lymphoma tumors and also for mitigation of radiation injury in normal tissues.
Abstract ID 0223
Enhancing Radiation Biodosimetry Capability
A. Alok, A. Kumar, S. Kulshrestra, S. Choudhary, S. Bhagi, J. S. Adhikari, N. K. Chaudhury
Div of Radiation Biodosimetry, Institute of nuclear Medicine and Allied Sciences, DRDO, Delhi 110054
Biodosimetry laboratories are necessary for quick and accurate assessment of absorbed radiation dose in suspected individuals for their medical management. The method is based on dicentric chromosomal assay (Gold standard). This assay is completely manual and time consuming, require skill and competency of laboratory staff. There is a necessity of more biodosimetry labs within country and networking within and at international level for enhancing medical preparedness for management of radiation emergency. Biodosimetry lab at Institute of Nuclear Medicine and Allied Sciences is established with facility of automated Microscope for cytogenetic analysis of samples for TRIAGE. The linear quadratic dose response fitting coefficients are α= 0.015±0.008, ß= - 0.052±0.002, c= 0.003±0.002 and P=0.10. Farther, the lab has undertaken rigorous interlab comparison with biodosimetry lab (accriditated by AERB) of Sri Ramachandra University, Chennai for assuring quality control. The lab has also established dose response calibration curve using Cytokinesis Blocked Mirco Nuclei(CBMN) Assay as alternative method. Triage is an important aspect of medical management and treatment. Gamma H2AX assay, an emerging radiation biomarker, effort has been made to establish the dose response of foci per cell (frequency) in lymphocytes. The frequency i.e., foci per cell has been optimized using various changes in protocol to achieve optimum sensitivity at 1 Gy with foci/cell as 7.49±0.30 in ex vivo irradiated human peripheral blood. Further activities are in progress for enhancing Biodosimetry capacity.
Abstract ID 0224
Modified γ-H2AX Protocol: Expanding the Horizon of γ-H2AX Assay for Biodosimetry
Rajesh Kumar Chaurasia , K. B. Shirsath, Usha Yadav, Utkarsha Desai, N. N. Bhat, and B. K. Sapra
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
In spite of having multiple safety measures, there is always a possibility of occurrence of radiological incidents. The rapid identification of individuals exposed to critically high radiation doses is of prime importance for initial triage and medical treatment decision. Ionizing radiation induces Double Strand Breaks (DSBs) among a broad spectrum of DNA lesions. Detection of radiation-induced DSBs in vivo using the γ-H2AX assay has been utilized as a potent tool for dose estimation. The limitation associated with γ-H2AX assay is the decay of signal over the time due to DSB repair, which is likely to happen during transport of blood sample to assessing lab. We have developed a modified protocol to address this problem using modified γ-H2AX protocol. Human peripheral blood samples were collected from healthy human volunteers and treated with various doses of 60Co γ-rays. To inhibit DNA repair, samples were immediately fixed with paraformaldehyde, and incubated over different period of time to mimic the actual emergency exposure situations. Lymphocytes were recovered using histopaque density gradient centrifugation. Results indicate a good amount of recovery of lymphocytes even at longer period of incubation after fixation. Efforts were made to visualize γ-H2AX foci following immunocytochemistry using respective primary and secondary (fluorescent labelled) antibodies. Number of γ-H2AX foci observed, were found to be same in both (1) fresh and (2) fixed and incubated blood samples, treat with same conditions. In conclusion early fixation of samples will be useful for delayed processing and dose estimation due to unavoidable time constraints while performing the assay.
Abstract ID 0229
Cervical Cancer Stem Cells and Correlation with Radiation Response in Locally Advanced Cervical Cancer
Supriya Chopra *, Kedar Deodhar # , Jayant Sastri Goda*, Venkatesh Pai*, Nidul Rathod*, NiyatiSudhalkar*, Sanjeev Waghmare*, Pritha Ray*, Reena Engineer # , Umesh Mahantshetty # , Sudeep Gupta*, Shyam K Shrivastava # .
*Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre., #Tata Memorial Hospital, Tata Memorial Centre.
While tumour-initiating cells (TIC) have been reported across solid tumours, there is dearth of data regarding TICs and radiation response in cervical cancer. From October, 2013- July, 2015 patients with locally advanced cervical cancer were included. Pretreatment biopsy was obtained. IHC was performed for SOX-2,OCT-4,Nanog (ESC) ,CD44 and Podoplanin (TIC). Semiquantitative scoring was used for IHC.All patients received uniform concurrent chemoradiation and brachytherapy. On follow up, local control and distant relapse was recorded. Correlation was evaluated between ESC and TIC expression and local control and distant relapse. p<0.05 was considered statistically significant. Overall 102 patients were accrued ofwhich 87 patients received treatment at TMC.Moderate to intense expression of Sox-2, Oct-4 and Nanog was recorded in 20.4%, 7.9% and 29.6% patients respectively. Expression of TICs, CD44 and Podoplanin was observed in 35.2% and 10.2% of samples respectively. Strong co-expression was observed between all ESCs (Nanog, Oct-4, Sox-2) and TICs (p<0.0001). Overall 9% and 12.6% patients had local and/or distant relapse. Moderate to strong expression of ESC Nanog correlated with local relapse and distant metastasis (p<0.0001, 0.0001). Low podoplanin expression was however associated with reduced local control and increased distant metastasis rate (p<0.0001, 0.0001). Coexpression of ESC and TIC highlights the possibility of these markers being used to isolate cervical cancer stem cells. This first report of correlation of Nanog and Podoplanin with outcomes suggests the need to develop and investigate the "cancer stem cell" hypothesis and investigate their molecular niches in cervical cancer.
Abstract ID 0230
Radioactive Gold Nanoparticles with Beta Energy and Auger Electron Cascades in Nanomedicine: Green Nanotechnology and Radiochemical Approaches
Kattesh V. Katti Curators' Professor of Radiology and Physics, Margaret Proctor Mulligan Distinguished Professor of Cancer Research; Director, Institute of Green Nanotechnology, University of Missouri Cancer Nanotechnology Platform, University of Missouri Medical School; One Hospital Drive, Columbia, Missouri 65212, USA
Auger electron, once neglected for oncological applications because of their low energy and consequent short range, have now become attractive due to our discovery of the production of biocompatible Au-198 nanoparticles. 198 Au provides a desirable beta energy emission and half-life that destroys tumor cells/tumor tissue (beta max = 0.96 MeV; half-life of 2.7 days). Its penetration range (up to 1100 cell diameters) is sufficiently long to provide cross-fire effects to destroy tumor cells, but short enough to minimize radiation exposure to tissues near the capsule periphery. Our recent studies have generated extensive therapeutic efficacy data (Katti et.al: PNAS 2012) from the treatment of tumors in mice and tumor bearing dogs (where the disease mimics human cancers). These findings have presented compelling prospects for the clinical translation of Auger electron-emitting radionuclides (such as Au-198) in treating human cancer patients. In our continued efforts to apply Green Nanotechnology for the development of therapeutic radioactive gold nanoparticles, we have developed a new generation of Au-198 theranostic probes. Laminin receptors are overexpressed in a large number of human tumors and the high in vivo affinity of EGCG toward Laminin receptors has allowed us to develop Laminin receptor specific radioactive gold nanoparticles to achieve tumor specificity. This lecture will provide: (a) Oncological aspects of Auger electrons through nanomedicine; (b) details on the intervention of nuclear activation analysis and various radioanalytical approaches for the production of tumor specific radioactive gold-198 nanoparticles; and (c) full in vivo investigations on therapeutic properties of EGCG-198-AuNP agent in treating prostate tumors.
Abstract ID 0231
Radiogenomics in the Cancer Clinic: Is it Ready for Prime Time?
In-Charge, Cancer Genetics Unit and Professor of Radiation Oncology, Tata Memorial Centre, Navi Mumbai
Clinical radiotherapy has made major strides with improved therapeutic ratio. Improved tumour control and reduced toxicities has been possible with better understanding of the radiobiology along with technical advancements for highly conformal dose delivery. Radiogenomics is the systematic study of the gene alterations and polymorphisms, which can predict normal tissue toxicity and tumour response for a given radio-biologically equivalent dose. Of the different types of genetic alterations evaluated in radiogenomicstudies, the most frequently reported are the single nucleotide polymorphisms (SNPs). Developing assays which can predict toxicity and response with a given radiotherapy protocol is an intense area of translational research and a radiogenomics consortium has been formed (http://epi.grants.cancer.gov/radiogenomics/). As expected for ionizing radiation, the DNA repair pathways are of greatest relevance from among the various pathways studied. As part of the International Cancer Genome Consortium (ICGC) - India project, we have done whole exome/genome sequencing on paired tumour (somatic mutation) and blood (germline mutation) in a cohort of oral cancer patients treated with surgery and adjuvant radiotherapy +/- chemotherapy. Influence of germline and somatic mutation in the Double strand DNA repair geneson radiation toxicity, disease free and overall survival shows several significant association. Mutations in the arachidonic acid metabolism pathway genes also shows significant association with clinical outcome. Evaluation of a larger dataset of The Cancer Genome Atlas (TCGA) and ICGC shows similar results. Other studies have evaluated the hypoxia genes and clinical outcome and how this could be modulated by hypoxic cell sensitizers. Radiogenomics holds promise for identifying subset of patients at higher risk of developing radiation toxicities or poor tumour control. This could help individualize the multi-modality treatment approach the radiotherapy protocol. Whether radiogenomics is ready to be incorporated in clinical decision making will be discussed.