MicroRNA­4712­5p promotes proliferation of the vulvar squamous cell carcinoma cell line A431 by targeting PTEN through the AKT/cyclin D1 signaling pathways.

ABSTRACT

The aim of the present study was to screen differentially expressed miRNAs in vulvar squamous cell carcinoma (VSCC), observe the role of microRNA­4712­5p in VSCC and investigate its targets and regulatory mechanism. Differentially expressed miRNAs in human VSCC tissues were screened. microRNA­4712­5p was selected and its expression level was verified in clinical tissue samples and the VSCC cell line A431 by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) analysis. The overexpression vector of microRNA­4712­5p was prepared and transfected into A431 cells; subsequently, cell invasion and metastasis were examined by Cell Counting Kit­8 and Transwell migration assays. Furthermore, the target gene of miRNA­4712­5p was predicted by bioinformatics and verified by The Dual­Luciferase® 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)3ß and cyclin D1, were detected by western blot assays. The expression level of microRNA­4712­5p 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 miR­4712­5p. RT­qPCR revealed that PTEN expression was markedly lower in VSCC tissues compared with that in adjacent tissues. After A431 cells were transfected with the miRNA­4712­5p overexpression vector, phospho­AKT (p­AKT) and cyclin D1 expression were notably increased, but miRNA­4712­5p­targeted PTEN and phospho­GSK3ß (p­GSK3ß) protein markedly decreased. Therefore, microRNA­4712­5p can reduce the expression of PTEN, further affecting its downstream p­AKT, p­GSK3ß and cyclin D1 signaling pathways, promoting the proliferation and invasion of VSCC.