2021 Fiscal Year Final Research Report
Effect of hypoxia on the repair process of radiation-induced DNA double-strand breaks
Project/Area Number |
19K08215
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 52040:Radiological sciences-related
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Research Institution | National Institutes for Quantum Science and Technology |
Principal Investigator |
Hirayama Ryoichi 国立研究開発法人量子科学技術研究開発機構, 量子医科学研究所 重粒子線治療研究部, 主幹研究員 (90435701)
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Co-Investigator(Kenkyū-buntansha) |
平野 祥之 名古屋大学, 医学系研究科(保健), 准教授 (00423129)
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | 放射線 / 重粒子線 / DNA二本鎖切断 / 微小核形成 / 低酸素 |
Outline of Final Research Achievements |
Cancer tissues contain hypoxic regions that are considered to be ineffective against anticancer drugs and ionizing radiation, and eradication of these hypoxic cancer cells is important in cancer therapy by ionizing radiations. Since hypoxic cells in cancer tissues remain hypoxic condition for a certain period of time after irradiation, it is not clear how radiation-induced double-strand breaks (DSBs) are modified by hypoxia. In this study, we examined DSBs and micronuclei formation on frequency to investigate the effects of oxic/hypoxia on the damage repair process at the DNA and chromosome levels. DSBs repair efficiency showed a decrease under hypoxic condition, and even heavy particle induced DSBs showed a similar trend. On the other hand, no effect of oxygen during repair was observed in micronuclei formation.
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Free Research Field |
放射線生物物理学
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Academic Significance and Societal Importance of the Research Achievements |
腫瘍の中には様々な酸素濃度の異なる細胞が存在し、放射線照射後も様々な酸素濃度の微小環境下で生物応答が行われている。しかし、このような状況を模擬した研究報告はほとんど無いため、放射線の照射前、中、後を低酸素状態に保つことで、実際の腫瘍内の微小環境の一部を模擬することが、重要と考えた。その結果、本研究からは放射線照射後の酸素濃度の違いが異なる生物応答を誘導することを発見した。放射線照射後の生物応答に酸素濃度が深く関わることは、分割照射の間隔や薬剤併用の投与タイミングを考える上で重要な知見と考え、放射線がん治療の高度化に有益な成果を提供したものと考えられる。
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