Elucidation of radiation biological effect with quantitative and qualitative analyses of base damage cluster

2015 Fiscal Year Final Research Report

• Project/Area Number: 25340034
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Risk sciences of radiation and chemicals
• Research Institution: Saga University
• Principal Investigator: Terato Hiroaki 佐賀大学, 総合分析実験センター, 准教授 (00243543)
• Co-Investigator(Kenkyū-buntansha): KONDO Toshihiro 佐賀大学, 総合分析実験センター, 教務員 (20186852)
• Co-Investigator(Renkei-kenkyūsha): TOKUYAMA Yuka 佐賀大学, 総合分析実験センター, 教務員 (30398135)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 電離放射線 / DNA損傷 / DNA修復 / 重粒子放射線 / 放射線生物影響 / 線エネルギー付与（LET） / 生物学的効果比（RBE）

Outline of Final Research Achievements

Clustered DNA damage is a specific type of DNA damage with ionizing radiation. In this study, we analyzed the yield of clustered base damage in cultured cells irradiated with various heavy ion beams, and investigated the repair process in post-irradiation cultured cells. Chinese hamster ovary (CHO) cells were irradiated by carbon, silicon, argon and iron ion beams with LETs of 13, 55, 90 and 200 keV/μm, respectively. The cell electrophoresis indicated that clustered base damage yields decreased as the LET increased. Then, clustered DNA damage repair was investigated using DNA repair mutant cells. DNA double-strand breaks accumulated in the mutant cells lacking Xrcc1 after irradiation, and the cell viability decreased. On the other hand, mouse embryonic fibroblast (Mef) cells lacking both Nth1 and Ogg1 became more resistant than the wild type. Thus, clustered base damage seems to be involved in the expression of heavy ion beam biological effects via the repair process.

Free Research Field

放射線生物学