Investigation of cancer immune evasion mechanism of recurrence after Transarterial Embolization and development of novel treatment strategies

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K16770
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Nara Medical University
• Principal Investigator: Matsumoto Takeshi 奈良県立医科大学, 医学部附属病院, 研究員 (50790309)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 肝動脈塞栓術 / ラット / ガン免疫逃避機構

Outline of Final Research Achievements

In our study, we aimed to improve the therapeutic outcomes of transarterial embolization (TAE) for hepatocellular carcinoma by developing a novel treatment strategy combining TAE with inhibitors of cancer immune evasion mechanisms in animal experiments. Using a rat model of hepatocellular carcinoma, we created five groups: untreated group, TAE alone group, anti-PD-L1 antibody alone group, TAE combined with anti-PD-L1 antibody group, and intraperitoneal saline group. Tumor necrosis rates and the expression of PD-L1 and CD8 were evaluated through imaging and pathological analysis. Although the combined treatment of TAE and cancer immune evasion mechanism inhibitors did not demonstrate improved therapeutic outcomes, increased expression of PD-L1 and CD8 in the intratumoral and peritumoral region was observed in the embolization groups compared to the untreated group.

Free Research Field

放射線医学

Academic Significance and Societal Importance of the Research Achievements

今回、ガン免疫逃避機構の視点から肝動脈塞栓術後の再発メカニズムを明らかにし、再発を阻止するための新規治療の構築を目指したが、肝動脈塞栓術とガン免疫逃避機構阻害薬の併用治療による治療成績の向上は今回示すことはできなかった。原因としてはガン免疫逃避機構にはPD-L1だけでなく制御性Ｔ細胞、骨髄由来抑制細胞など様々な因子があり、今後他の免疫チェックポイント分子を標的とする抗体や、免疫抑制細胞に対する阻害薬を用いて最も抗腫瘍効果の高い治療方法の開発を目指す。