Analysis of cancer cell dynamics after proton irradiation using real-time imaging

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K17175
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Aichi Cancer Center Research Institute (2022); Nagoya City University (2019-2021)
• Principal Investigator: Hashimoto Shingo 愛知県がんセンター(研究所), 分子腫瘍学分野, 研究員 (90803510)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 陽子線 / X線 / DNA二本鎖切断 / γH2AX / 遊走能

Outline of Final Research Achievements

Experiments were performed on cultured cells using X-ray and proton beam. In this study, the migration ability after irradiation experiments was examined using time-lapse images, and no significant difference could be shown. On the other hand, it was suggested that the migration ability may differ transiently depending on the irradiation dose and the type of beam. Proton beam have the characteristic of low dose exposure at the proximal end and high dose exposure at the distal end, and may have different cellular effects at the proximal and distal ends. Although γH2AX is often used to predict cell viability, the optimal timing of the evaluation in the low-dose range is unknown and needed to be investigated. The optimal timing of γH2AX evaluation for cell viability prediction after low (10 mGy) to high (4000 mGy) doses of X-rays was 12 hours after irradiation.

Free Research Field

放射線腫瘍学

Academic Significance and Societal Importance of the Research Achievements

陽子線は一つのビームの中で近位端の低線量被曝領域と遠位端の高線量被曝領域が混在しているという物理的な特性をもつ。10~4000mGy領域におけるX線照射後の細胞生存率予測に最適なγH2AX評価タイミングを確立することができた。これを用いて低線量被曝領域と高線量被曝領域における陽子線とX線の放射線生物学的な効果の推定につなげていくことができ、陽子線治療の最適な治療指針の確立という目的に向けて有意義なものと考えられる。