MicroRNA-4649-3p inhibits cell proliferation by targeting protein tyrosine phosphatase SHP-1 in nasopharyngeal carcinoma cells.

The present study aimed to investigate the influence of microRNA-4649-3p on nasopharyngeal carcinoma (NPC) cell proliferation and how it regulated SHP-1 expression. The online software TargetScan was used to predict the microRNAs targeting SHP-1 and identified that miR-4649-3p was one of the possible miRNAs targeting SHP-1. Subsequently, quantitative polymerase chain reaction (PCR) was used to detect the expression level of miR-4649-3p and SHP-1 mRNA in different NPC cell lines. The miR-4649-3p mimics and inhibitors were transfected into NPC cells and cell proliferation was examined by the MTT assay. The SHP-1 expression level was determined by PCR and western blot analysis. Lentivirus containing the SHP-1 gene and miR-4649-3p mimics was co-transfected into the NPC cells and cell proliferation was detected by the MTT assay. The expression level of miR-4649-3p and SHP-1 mRNA was negatively correlated in the NPC cell lines. miR-4649-3p mimics suppressed NPC cell proliferation whereas miR-4649-3p inhibitors promoted NPC cell proliferation. The SHP-1 expression level was suppressed when transfected with miR-4649-3p mimics in NPC cells. The miR-4649-3p inhibitors increased SHP-1 expression. The luciferase reporter assay showed that miR-4649-3p directly targeted SHP-1 by binding to the 3'-untranslated region of SHP-1 mRNA. Overexpression of SHP-1 inversed the inhibited effect of miR-4649-3p mimics on cell proliferation. In conclusion, miR-4649-3p inhibits cell proliferation by targeting SHP-1 in NPC cells.