MicroRNA-490-3p inhibits proliferation of A549 lung cancer cells by targeting CCND1.

MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate the translation of messenger RNAs by binding their 3'-untranslated region (3'UTR). In this study, we found that miR-490-3p is significantly down-regulated in A549 lung cancer cells compared with the normal bronchial epithelial cell line. To better characterize the role of miR-490-3p in A549 cells, we performed a gain-of-function analysis by transfecting the A549 cells with chemically synthesized miR-490-3P mimics. Overexpression of miR-490-3P evidently inhibits cell proliferation via G1-phase arrest. We also found that forced expression of miR-490-3P decreased both mRNA and protein levels of CCND1, which plays a key role in G1/S phase transition. In addition, the dual-luciferase reporter assays indicated that miR-490-3P directly targets CCND1 through binding its 3'UTR. These findings indicated miR-490-3P could be a potential suppressor of cellular proliferation.