The effects of multiple low dose irradiations on radioresistant cancer cells and their mechanisms

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K15537
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Hirosaki University
• Principal Investigator: TERASHIMA SHINGO 弘前大学, 保健学研究科, 助教 (00583733)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 低線量放射線 / 放射線抵抗性細胞 / 低酸素細胞 / 複数回照射

Outline of Final Research Achievements

I have demonstrated that low dose pulsed radiation at a high-dose-rate, even for very short intervals, decreases cell survival to a greater extent than single exposure to a similar total dose and dose rate. In this study, I demonstrated that the above irradiation method enhanced the cell lethal effect on effect on clinically radioresistant cells, exhibit radioresistance and continue to proliferate stably even after daily irradiation with 2 Gy, and radioresistant hypoxic. The effect of increased DNA double-strand breaks that remain unrepaired after irradiation and delayed reactive oxygen species were suggested as contributing factors to the mechanism.

Free Research Field

放射線生物学

Academic Significance and Societal Importance of the Research Achievements

放射線治療では、放射線抵抗性の癌細胞による再発が問題となっておりその制御が課題となっている。本研究の結果より、高線量率で低線量放射線を短時間のインターバルで複数回照射する手法は、薬剤を使用せずに簡便に低酸素細胞を含む放射線抵抗性細胞に対して感受性を向上させる有効な手法であり薬剤の仕様による追加の副作用がなく、また放射線治療装置の時間的な面でも効率的である。本手法は臨床への応用を考えたときに簡便に放射線治療の局所制御率の向上が期待できる。