Decreased expression of miR-490-3p in colorectal cancer predicts poor prognosis and promotes cell proliferation and invasion by targeting RAB14

Growing evidence indicates a potential role for miR-490-3p in tumorigenesis. However, its function in colorectal carcinoma (CRC) remains undefined. In this study, miR-490-3p was markedly downregulated in fifty colorectal cancer tissue samples compared with the corresponding adjacent non-cancerous specimens, by reverse transcription- quantitative polymerase chain reaction (RT-qPCR). The expression levels of miR-490-3p were closely associated with tumor differentiation and distant metastasis. In addition, both Kaplan-Meier and multivariate analyses indicated CRC patients with elevated miR-490-3p amounts had prolonged overall survival. Overexpression of miR-490-3p markedly reduced proliferation, colony formation and invasion in CRC cells by enhancing apoptosis and promoting G2/M phase arrest. Furthermore, ectopic expression of miR-490-3p resulted in decreased expression of RAB14, which was directly targeted by miR-490-3p, as shown by the dual-luciferase reporter gene assay. Finally, in a nude mouse model, miR-490-3p overex-pression significantly suppressed the growth of CRC cells. The above results indicated that miR-490-3p might constitute a prognostic indicator and a novel molecular target for miRNA-based CRC therapy.