Real-time visualization of radiation-induced intratumoral cell death and its application to radiation therapy

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K07654
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Kitasato University
• Principal Investigator: Kagiya Go 北里大学, 医療衛生学部, 教授 (30524243)
• Co-Investigator(Kenkyū-buntansha): 小川 良平 富山大学, 学術研究部医学系, 准教授 (60334736)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 細胞死 / アポトーシス / リアルタイム可視化 / 腫瘍血管損傷

Outline of Final Research Achievements

The aim of this study was to visualize cell death induced by X-ray irradiation and to elucidate the mechanisms of cell death induced within tumors. We focused on apoptosis among cell death and constructed apoptosis-imaging cells. Employing these cells, we successfully visualized X-ray-induced apoptosis in vitro and achieved real-time visualization with minimal invasiveness in tumor-bearing mice transplanted with these imaging cells. Based on luminescence data analysis, we demonstrated that the immune system is less involved in the apoptosis within tumors induced early after X-irradiation, and that nutrient depletion in cancer tissue secondary to tumor vascular damage is the main cause. This is one of the main factors determining the lethal effect of radiation on tumor cells.

Free Research Field

放射線治療生物学

Academic Significance and Societal Importance of the Research Achievements

腫瘍内で誘発される細胞死を可視化するシステムは、腫瘍内細胞死の動態解析を簡便にし、放射線治療条件の最適化や抗癌剤併用の放射線化学療法の開発等、治療への応用に有用な手段となる。本研究により腫瘍内細胞死（アポトーシス）は、がん細胞の放射線感受性だけでなく、放射線による腫瘍血管損傷を起因とし誘発されることが証明された。これらの知見は放射線治療や免疫治療を組み合わせた新規治療法の開発につながる研究である。