Frontiers in Oncology (Sep 2023)

miR-186-ANXA9 signaling inhibits tumorigenesis in breast cancer

  • Zhongrui Wang,
  • Zhongrui Wang,
  • Xiqian Zhou,
  • Xiaochong Deng,
  • Danrong Ye,
  • Diya Liu,
  • Baian Zhou,
  • Wenfang Zheng,
  • Xuehui Wang,
  • Yuying Wang,
  • Oyungerel Borkhuu,
  • Lin Fang,
  • Lin Fang

DOI
https://doi.org/10.3389/fonc.2023.1166666
Journal volume & issue
Vol. 13

Abstract

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Breast cancer (BC) ranks as the highest incidence among cancer types in women all over the world. MicroRNAs (miRNAs) are a class of short endogenous non-coding RNA in cells mostly functioning to silence the target mRNAs. In the current study, a miRNA screening analysis identified miR-186-5p to be downregulated in human breast cancer tumors. Functional studies in vitro demonstrated that overexpression of miR-186-5p inhibited cellular proliferation and induced cell apoptosis in multiple breast cancer cell lines including MDA-MB-231, MCF-7, and BT549 cells. Transplantation of the miR-186-5p-overexpressing MDA-MB-231 cells into nude mice significantly inhibited mammary tumor growth in vivo. Sequence blast analysis predicted annexin A9 (ANXA9) as a target gene of miR-186-5p, which was validated by luciferase reporter assay, QRT-PCR analysis, and western blot. Additional gene expression analysis of clinical tumor samples indicated a negative correlation between miR-186-5p and ANXA9 in human breast cancer. Knockdown of ANXA9 mimicked the phenotype of miR-186-5p overexpression. Reintroduction of ANXA9 back rescued the miR-186-5p-induced cell apoptosis. In addition, miR-186-5p decreased the expression of Bcl-2 and increased the expression of p53, suggesting a mechanism regulating miR-186-5p-induced cellular apoptosis. In summary, our study is the first to demonstrate miR-186-5p-ANXA9 signaling in suppressing human breast cancer. It provided a potential therapeutic target in breast cancer.

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