MicroRNA‑409‑5p inhibits cell proliferation, and induces G₂/M phase arrest and apoptosis by targeting DLGAP5 in ovarian cancer cells

Abstract

MicroRNA (miRNA/miR)‑409‑5p has been reported to be implicated in prostate and breast cancers; however, its functional role in ovarian cancer (OC) remains unclear. Therefore the aim of the present study was to investigate the clinical significance and biological function of miR‑409‑5p in OC. Here, reverse transcription‑quantitative PCR analysis was performed to detect miR‑409‑5p expression in OC tissues and cell lines. The association between miR‑409‑5p expression and the clinicopathological characteristics of patients with OC was assessed using the Fisher's exact test. Furthermore, the Cell Counting Kit‑8 assay was performed to assess cell proliferation. Cell cycle distribution and apoptosis were evaluated via flow cytometric analysis, and the target gene of miR‑409‑5p was validated via the dual‑luciferase reporter assay. The results demonstrated that miR‑409‑5p expression was significantly downregulated in OC tissues and cell lines compared with adjacent normal tissues and epithelial cells, respectively. In addition, low miR‑409‑5p expression was significantly associated with tumor size (P=0.044) and the International Federation of Gynecology and Obstetrics staging system (P=0.005). Notably, overexpression of miR‑409‑5p suppressed cell proliferation, and induced G2/M phase arrest and apoptosis of OC cells. Mechanistically, discs large‑associated protein 5 (DLGAP5) was identified as a novel target of miR‑409‑5p, which was negatively regulated by miR‑409‑5p. DLGAP5 expression was significantly upregulated in OC tissues and cell lines compared with adjacent normal tissues and epithelial cells, respectively. Furthermore, overexpression of DLGAP5 reversed the effects of miR‑409‑5p on SKOV‑3 cell proliferation, and G2/M phase and apoptosis. Taken together, these results suggest that miR‑409‑5p acts as a tumor suppressor in OC by modulating DLGAP5 expression.