Minimally invasive cancer treatment strategy using hyper-radiosensitivity in low-dose repeat irradiation - a Glioblastoma study

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K10492
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Keio University
• Principal Investigator: Fukada Junichi 慶應義塾大学, 医学部(信濃町), 講師 (50338159)
• Co-Investigator(Kenkyū-buntansha): 公田 龍一 慶應義塾大学, 医学部(信濃町), 助教 (00464834) ; 小池 直義 慶應義塾大学, 医学部(信濃町), 助教 (60464913)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: Glioma / 放射線感受性 / 細胞周期

Outline of Final Research Achievements

We focused on hyper-radiosensitivity at low dose irradiation as a treatment for glioblastoma, a refractory malignant tumor. Thirty-minute intervals showed a good response for a low-dose irradiation interval compared to other shorter intervals in several malignant glioma cell lines. We performed cell cycle observation after irradiation at several time course. The change was not significant in 30 minutes and 3hours but remarkable in about 5 hours. The most prominent foci fluorescence due to DBA damage repair was observed in the cells collected 30 minutes after irradiation but the difference in foci number between single and repeated irradiation was unclear. It was difficult to sort M-phase cells by the shake-off method. The cell ratio of M phase by irradiation was measured by immunostaining. We conclude that repeated irradiation is an effective treatment because the reaction is good because it causes migration to the cell cycle that is radiosensitive during repeated irradiation.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

膠芽腫が治療抵抗性であることから放射線超感受性に着目した抗腫瘍効果の増強を探索する試みは重要と考える。また再発時に再度放射線療法が期待されることから低線量放射線照射に関する研究は重要である。放射線増感剤の探索、遺伝子解析を用いた放射線超感受性の機序解明を進めることで、放射線生物学的にも重要な研究と考えている。
本研究を発展させ、臨床応用可能な低線量反復照射を提案できれば、照射線量を低減した治療が実現可能となる。これは、正常組織の有害事象低減のみならず、患者さん、医療従事者の負担軽減にもつながり、難治性とされてきた膠芽腫に対する新しい治療戦略を提示する意義深い研究であると考えている。