What are the effects of different radiation qualities on carcinogenesis?

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K12336
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 63020:Radiation influence-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: Tsuruoka Chizuru 国立研究開発法人量子科学技術研究開発機構, 放射線医学研究所 放射線影響予防研究部, 主任研究員 (60415411)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 放射線発がん / 線質の違い / 基底細胞がん

Outline of Final Research Achievements

Carcinogenesis is important when considering the late effects of radiation exposure. It is also essential to evaluate the risk of carcinogenesis for each radiation quality. We investigated the characteristics of gamma-rays-, neutron-, and carbon-ion-induced cancers in Ptch1 heterozygous mice, a mouse model of radiation carcinogenesis. We observed that tumors developed in organs such as the liver, lung, spleen, skin, and muscle. Although the tumors of the liver, spleen, skin, and muscle were increased after irradiation, the radiation qualities were independent of the organ of carcinogenesis. Pathological diagnosis of the skin tumors revealed that they were basal cell carcinomas. The morpheaform/sclerosing and micronodular types of basal cell carcinomas tended to increase after carbon-ion and neutron exposure, suggesting that some radiation qualities can cause poor prognosis. However, the radiation-specific characteristics were not observed in the molecular analysis.

Free Research Field

放射線生物

Academic Significance and Societal Importance of the Research Achievements

放射線の線質が異なると生物効果は異なり、それら放射線の発がんリスクを正確に評価することは必須である。被ばくによる疫学研究にはさまざまな不確実性があり、さらに多様な種類の放射線による知見を得ることは困難である。そのため、動物実験を用いてさまざまな放射線の発がんリスク、臓器依存性、メカニズムの解明をすることは、将来的に被ばくをした時の発がん予測に役立つとともに、発がん予防法開発に貢献できる基礎データとなりうる。