MicroRNA-204-3p modulates epithelial-mesenchymal transition by targeting paired box gene 2 in human melanoma A-375 cells

BACKGROUND: Paired box 2 gene promoted the progression of subsequent epithelial-mesenchymal transition (EMT) in malignant melanoma, which is the most dangerous type of skin cancer. We aimed to investigate the functional role of miR-204-3p in metastatic melanoma. METHODS: To study the effects of overexpressed miR-204-3p on the melanoma cells, miR-204-3p mimic vector were transfected into A-375 cells for detecting the cell viability using CCK-8 kit. Wound healing and Transwell assays were performed to assess the migration and invasion capacities of melanoma cells. TargetScan and miRTarBase were used to predict the potential target of miR-204-3p, which was subsequently verified by dual-luciferase assay. The expressions of several EMT-associated genes were determined by quantitative real-time polymerase chain (qRT-PCR) and Western blot. RESULTS: The expression of miR-204-3p in several melanoma cell lines was lower than that in HaCaT cells. After transfecting with the miR-204-3p mimic vector, the cell viability of A-375 cells decreased over time and significantly reduced at 48 h (P<0.01). Overexpression of miR-204-3p noticeably suppressed the migration and invasion abilities of A-375 cells (P<0.01). PAX2 and guanine nucleotide binding protein (G protein) q polypeptide (GNAQ) were the potential targets of miR-204-3p, which could effectively silence PAX2 rather than GNAQ. MiR-204-3p overexpression could upregulate the epithelial cadherin (E-cadherin) and downregulate the vimentin, matrix metalloproteinase 2 (MMP2) and MMP-9 at transcriptional and posttranscriptional levels. CONCLUSIONS: Our results revealed that miR-204-3p had inhibitory effects on the migratory and invasive capacities and EMT progression in malignant melanoma through targeting PAX2.