Analysis of biological factors involved in tumor immunity and its application to personalized radiotherapy.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K16764
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Sapporo Medical University
• Principal Investigator: Tsuchiya Takaaki 札幌医科大学, 医学部, 助教 (90631169)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 腫瘍免疫 / リキッドバイオプシー / 放射線治療 / 治療効果予測

Outline of Final Research Achievements

We investigated the expression of miRNAs in exosomes and tumor-infiltrating CD8-positive and FoxP3-positive T cells in blood before treatment in patients with uterine cervical cancer treated with definitive radiotherapy. The results and their prognostic relevance were also investigated. As a result, we identified nine miRNA signatures that were differentially expressed with or without recurrence. The expression of some miRNA signatures was inversely correlated with the number of tumor-infiltrating CD8-positive and FoxP3-positive T cells, suggesting a possible association between tumor immunosuppression and suppression of chemoradiotherapy efficacy.
These results indicate that the use of miRNA signatures may improve noninvasive monitoring and personalized treatment of cervical cancer.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

近年、腫瘍免疫機構が解明されつつあり、臨床においても免疫チェックポイント阻害薬が承認され効果が認められている。しかし、放射線治療と腫瘍免疫機構の関連については未解明の部分が多い。この研究では子宮頸癌における腫瘍免疫関連タンパクの発現や腫瘍免疫の制御に関わる血中マイクロRNAと放射線治療の成績について比較検討を行っている。その結果、いくつかのmiRNAシグネチャの発現は腫瘍免疫との関連を示すとともに化学放射線治療の効果にも影響を及ぼしている可能性が示された。
これにより腫瘍免疫やmiRNAに基づいた個別化治療を行うことで、化学放射線治療の効果を高められる可能性がある。