• Users Online: 409
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
ORIGINAL ARTICLE
Year : 2018  |  Volume : 9  |  Issue : 4  |  Page : 183-189

Enhanced DNA double strand break repair triggered by microbeam irradiation induced cytoplasmic damage


1 Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
2 Department of Accelerator and Medical Physics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
3 Division of Agrotechnology and Biosciences, Malaysian Nuclear Agency, Kajang, Malaysia
4 Key Laboratory of Ion Beam Bioengineering, Hefei Institute of Physical Science, Chinese Academy of Sciences, Hefei, China

Correspondence Address:
Teruaki Konishi
Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba
Japan
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jrcr.jrcr_21_18

Rights and Permissions

Objective: Direct exposure of the nucleus to radiation, is the primary cause of various radiobiological effects. However, the cytoplasm is equally exposed to radiation during treatments that result in activation of intracellular response. Thus, the present study is aimed at investigating (1) whether cytoplasmic irradiation affects double-strand breaks (DSBs) repair when the cytoplasm (C) and nucleus (N) is irradiated sequentially, and (2) whether the cytoplasmic irradiation alone is sufficient to induce DNA DSBs in the nucleus. Materials and Methods: To distinguish the radiobiological effects between nuclear and cytoplasmic irradiation, all the experiments were conducted using the SPICE - National Institute of Radiological Sciences microbeam (SPICE) that can target precisely the N and/or C with desired number of 3.4 MeV protons. We examined the kinetics of DSB repair in WI-38 normal human fibroblast cells that were irradiated by microbeam targeted to the N, C, or N + C. Cells were fixed at various time points between 1 and 24 h postirradiation. Subsequently, they were immunostained with antibodies against γ-H2AX, a DSB marker, and imaged, to quantify the residual DSB in each nucleus. Results: Microbeam irradiation induced significant γ-H2AX, directly proportional to the number of protons delivered per N. In the C-targeted cells, γ-H2AX levels did not increase significantly, compared to controls, 1-h postirradiation. However, 4-h postirradiation, γ-H2AX levels were significantly increased in C-targeted cells, compared to nonirradiated controls, and the increase was proportional to the number of protons delivered. Cells irradiated with 500 protons per N, showed lowered residual γ-H2AX levels in N + C cells additionally irradiated with 500 or 1000 protons targeted to the C, 16 and 24 h postirradiation, respectively. Conclusion: Our results suggest that cytoplasmic damage triggers enhanced repair of DSBs that are induced on nucleus irradiation.


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed261    
    Printed26    
    Emailed0    
    PDF Downloaded44    
    Comments [Add]    

Recommend this journal