Development of a marker for prognostic treatment of prostate cancer using a new xenograft model

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K18565
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56030:Urology-related
• Research Institution: University of Miyazaki
• Principal Investigator: FUJII MASATO 宮崎大学, 医学部, 助教 (10794373)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 前立腺癌 / 去勢抵抗性 / PDX / IL13Ra2

Outline of Final Research Achievements

We focused on a molecule called IL13Ra2, which was highly expressed in the prostate cancer castration resistance model (PDX model), and examined whether it could be a treatment responsiveness predictor (predicting castration resistance). The IL13Ra2 forced expression prostate cancer cell line resulted in significant cell proliferation in androgen-depleted medium (castration medium). In animal experiments, differences were also observed in the rate of increase in tumor engraftment rate and castration reactivity. In addition, immunostaining using a sample of prostate cancer patients before treatment also showed a significantly higher rate of positive IL13Ra2 immunostaining in patients who later developed treatment-resistant prostate cancer. IL13Ra2 may be a predictor of the therapeutic effect of prostate cancer.

Free Research Field

前立腺癌

Academic Significance and Societal Importance of the Research Achievements

進行性前立腺癌に対する一次療法は去勢治療であるが、治療経過において去勢治療抵抗性となり増悪する前立腺癌が多くみられる。治療抵抗性前立腺癌に対しては複数の治療薬が存在し、早期の導入により治療効果が改善したなどの報告がある。しかし、去勢治療に対する反応性予測マーカーが無く、患者選択においての基準が困難である。今回検討したIL13Ra2は去勢抵抗性を予測し得る可能性があり、臨床応用されれば去勢治療抵抗性が予測される患者に予め適切な治療を受けて頂く事で、予後改善やQOL(生活の質)の維持に繋がる可能性がある。