Development of a Novel Therapeutic Agent for Hormone-Resistant Breast Cancer by Targeting the Growth Factor Receptor Pathway

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K18065
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 55010:General surgery and pediatric surgery-related
• Research Institution: Nagoya City University
• Principal Investigator: HISADA TOMOKA 名古屋市立大学, 医薬学総合研究院(医学), 助教 (30781835)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: RIN1 / ER陽性乳癌

Outline of Final Research Achievements

We investigated the relationship between RIN1 mRNA expression and clinicopathological factors and prognosis in breast cancer patients with long-term follow-up. As in previous reports, decreased RIN1 expression was associated with significantly poorer prognosis in all breast cancer patients and in ER-positive breast cancer patients. No significant difference was observed in ER-negative or triple-negative breast cancer. The hypothesis of an association with metastasis was formulated, but no association was found between axillary lymph node-positive cases and RIN1 expression, nor was there any association with prognosis (DFS/OS). Regarding resistance to hormone therapy, we analyzed the results separately for tamoxifen and aromatase inhibitors, and found that lower RIN1 expression was associated with shorter survival in patients treated with aromatase inhibitors.

Free Research Field

ER陽性乳癌

Academic Significance and Societal Importance of the Research Achievements

RIN1がER陽性乳癌の転移遊走能とホルモン療法抵抗性に影響しているのではないかとの仮説のもと本研究が計画したが、RIN1発現と腋窩リンパ節転移の有無に関連を認めなかった。ホルモン療法の抵抗性の解析では、臨床的に一般的に使用されるアロマターゼ阻害薬投与症例においてRIN1発現と全生存期間に相関を認めたため、その原因について検討する予定である。