MicroRNA‑4712‑5p promotes proliferation of the vulvar squamous cell carcinoma cell line A431 by targeting PTEN through the AKT/cyclin D1 signaling pathways.

The aim of the present study was to screen differentially expressed miRNAs in vulvar squamous cell carcinoma (VSCC), observe the role of microRNA‑4712‑5p in VSCC and investigate its targets and regulatory mechanism. Differentially expressed miRNAs in human VSCC tissues were screened. microRNA‑4712‑5p was selected and its expression level was verified in clinical tissue samples and the VSCC cell line A431 by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis. The overexpression vector of microRNA‑4712‑5p was prepared and transfected into A431 cells; subsequently, cell invasion and metastasis were examined by Cell Counting Kit‑8 and Transwell migration assays. Furthermore, the target gene of miRNA‑4712‑5p was predicted by bioinformatics and verified by The Dual‑Luciferase® Reporter (DLR™) Assay System. The expression of phosphatase and tensin homologue (PTEN) and its downstream proteins, such as protein kinase B (PKB; AKT), glycogen synthase kinase (GSK)3β and cyclin D1, were detected by western blot assays. The expression level of microRNA‑4712‑5p in VSCC tissues and the A431 cell line was found to be significantly increased, promoting proliferation and invasion of VSCC. The DLR™ assay indicated that PTEN was a target of miR‑4712‑5p. RT‑qPCR revealed that PTEN expression was markedly lower in VSCC tissues compared with that in adjacent tissues. After A431 cells were transfected with the miRNA‑4712‑5p overexpression vector, phospho‑AKT (p‑AKT) and cyclin D1 expression were notably increased, but miRNA‑4712‑5p‑targeted PTEN and phospho‑GSK3β (p‑GSK3β) protein markedly decreased. Therefore, microRNA‑4712‑5p can reduce the expression of PTEN, further affecting its downstream p‑AKT, p‑GSK3β and cyclin D1 signaling pathways, promoting the proliferation and invasion of VSCC.