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.