Elucidation of the developmental mechanism of prostate neuroendocrine cancer using microRNA expression analysis

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K09586
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56030:Urology-related
• Research Institution: Teikyo University
• Principal Investigator: KOJIMA SATOKO 帝京大学, 医学部, 客員准教授 (10345019)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 去勢抵抗性前立腺癌 / マイクロRNA / IGFBP-3

Outline of Final Research Achievements

Prostate cancer is usually a hormone-sensitive cancer that responds well to androgen deprivation therapy, but over time it becomes a hormone-resistant cancer, and its causes and mechanisms are still under investigation.In recent years, it has been found that among functional RNA molecules, microRNAs (microRNAs) play an important role as tumor suppressor genes even in prostate cancer.
So far, we have discovered that miR-455-5p suppresses the expression of tumor suppressor genes such as Pirin, IGFBP-3, and LRP8, and promotes prostate cancer proliferation and invasion. In this study, the expression of IGFBP-3 was examined by immunostaining in advanced prostate cancer, and it was shown that those with high expression were associated with poor prognosis. A tendency for IGHFB-3 expression to become stronger after castration-resistant prostate cancer was observed, suggesting a mechanism contributing to the progression of prostate cancer.

Free Research Field

前立腺癌

Academic Significance and Societal Importance of the Research Achievements

前立腺癌は早期癌であれば長期の予後が得られるが、再発再燃する場合がある。前立腺癌は通常ホルモン感受性癌で、アンドロゲン除去療法によく奏功するが、治療を長期に続けるにつれてホルモン抵抗性の癌になる。転移性前立腺癌の予後は、治療開始からホルモン再燃癌（去勢抵抗性前立腺癌）になるまで2年程度であったが、近年、新規ホルモン療法薬や抗癌剤の適応により、3～5年と以前に比べて再燃までの期間が延長され、長期の予後が期待されるようになった。しかし、いずれの治療も奏功せず、2～3年以内に死亡する症例も少なからず存在する。本研究で新たな分子学的アプローチが解明されればさらなる前立腺癌の予後の改善が期待できる。