Exploratory study of new diagnostic markers in small cell lung cancer

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K16378
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 50020:Tumor diagnostics and therapeutics-related
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: Sakakibara Rie 東京医科歯科大学, 大学院医歯学総合研究科, 助教 (80827288)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 肺小細胞癌 / INSM1 / 診断マーカー / 免疫染色

Outline of Final Research Achievements

INSM1 expression in resected specimens of primary lung cancer was positive in less than 10% of lung adenocarcinomas and 10% of lung squamous cell carcinomas, positive in over 90% of SCLC, positive in over 60% of LCNEC, and positive in over 90% of carcinoid, suggesting that INSM1 is specifically expressed in neuroendocrine tumors. In cell line experiments, INSM1 was expressed specifically in the In cell line experiments, INSM1 was negative in almost all adenocarcinoma cell lines by both immunohistochemical staining and Western blotting, but in small cell lung cancer lines, INSM1 was positive in about 80% of cases by both immunohistochemical staining and Western blotting. This study suggests that INSM1 is highly sensitive and specific for the detection of SCLC and may provide prognostic information.

Free Research Field

腫瘍

Academic Significance and Societal Importance of the Research Achievements

INSM1によってNE分化の経路に変化が起き、INSM1がSCLCの発生に関与していることが示唆された。現在の肺癌の診断には、肺腺癌ではTTF-1が、肺扁平上皮癌ではp40が、免疫染色による診断マーカーとして広く用いられているが、SCLCにおいては、単独で感度・特異度の高い診断マーカーが存在しなかったが、INSM1が単独でSCLCの新たな診断マーカーとなることを検索した本研究は、高い独自性を有する。研究においても微小検体を用いたINSM1の免疫染色が評価可能か、診断マーカーになり得るか解明することで、手術不能な進行再発SCLCにおいても診断への応用が期待できると考える。