MiR-376a suppresses the proliferation and invasion of non-small-cell lung cancer by targeting c-Myc.

It has been reported that miR-376a is involved in the formation and progression of several types of cancer. However, the expression and function of miR-376a is still unknown in non-small cell lung carcinomas (NSCLC). In this study, the expression of miR-376a in NSCLC tissues and cell lines were examined by real-time PCR, the effects of miR-376a on cell proliferation, apoptosis and invasion were evaluated in vitro. Luciferase reporter assay was performed to identify the targets of miR-376a. The results showed that miR-376a was significantly downregulated in NSCLC tissues and cell lines. Restoration of miR-376a in NSCLC cell line A549 significantly inhibited cell proliferation, increased cell apoptosis and suppressed cell invasion, compared with control-transfected A549 cells. Luciferase reporter assay showed that c-Myc, an oncogene that regulating cell survival, angiogenesis and metastasis, was a direct target of miR-376a. Over-expression of miR-376a decreased the mRNA and protein levels of c-Myc in A549 cells. In addition, upregulation of c-Myc inhibited miR-376a-induced inhibition of cell proliferation and invasion in A549 cells. Therefore, our results indicate a tumor suppressor role of miR-376a in NSCLC by targeting c-Myc. miR-376a may be a promising therapeutic target for NSCLC.