Study of anti-tumor immune effect induced by plasma irradiation to normal tissue

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K20995
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Ono Ryo 東京大学, 大学院新領域創成科学研究科, 教授 (90323443)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: プラズマ医療 / がん治療 / 免疫治療 / 正常組織照射 / ストリーマ放電

Outline of Final Research Achievements

In this study, it was shown that plasma irradiation to normal tissue of tumor-bearing mice have an anti-tumor effect on tumors distant from the irradiated area. When plasma was irradiated to the upper left back of the mice for 10 minutes a day for a total of 5 days, it was observed that the growth of mouse colon cancer Colon-26 tumor on the right flank, located far from the irradiated area, was slowed. This effect was observed only when the tumor volume on the first day of plasma irradiation was relatively small. Experiments using immunodeficient mice suggested that this antitumor effect of normal tissue irradiation was due to T cell-derived adaptive immunity.

Free Research Field

プラズマ応用工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、がんを有するマウスの正常組織に放電プラズマを照射すると、照射部から離れた場所にある腫瘍に抗腫瘍効果が得られることを示した。そして、この効果がマウスの抗腫瘍免疫反応によるものであることを示した。このような現象は、他の放射線治療などの分野でもほとんど観測されたことはなく、副作用が比較的小さいと考えられているプラズマの正常組織照射による、新たながん治療法の開発につながることが期待される。