Analysis of DNA repair mechanism after heavy-ion irradiaiton and its application to radiation therapy

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K10012
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Izumi Masako 国立研究開発法人理化学研究所, 仁科加速器科学研究センター, 専任研究員 (00280719)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 重粒子線

Outline of Final Research Achievements

The heavy-ion irradiation is used as a radiation therapy, although DNA repair mechanism is not fully understood. In this research, the number of DNA double strand breaks or the foci of DNA repair proteins were analyzed after X-ray or heavy-ion irradiation with various linear energy transter in mammalian cells where specific DNA repair pathways were inhibited by the lack of DNA repair proteins genetically or the pretreatment of inhibitors against DNA repair proteins. The main repair pathway for DNA double strand breaks after both X-ray or heavy-ion irradiation was non-homologous end joining. In addition, homologous recombination could complement the defect of non-homologous end joining after X-ray irradaition, but not after high energy heavy-ion irradiation completely.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

重粒子線は、X線に比べて高い致死効果を持つこと、標的部分のみに高い放射線量を与えることが可能であること、酸素効果の影響を受けにくいことから、先進的ながん治療法として利用されている。しかし、重粒子線に特異的なDNA損傷修復機構は完全に解明されていない。本研究は、重粒子線照射後のDNA損傷修復の理解に寄与するだけではなく、将来的には重粒子線照射とDNA修復阻害剤（抗がん剤）を組み合わせた新しい治療法の開発や、宇宙空間における有人飛行の放射線リスク評価に寄与することが期待できる。