MiR-34c-3p suppresses the proliferation and invasion of non-small cell lung cancer (NSCLC) by inhibiting PAC1/MAPK pathway.

MicroRNAs have become recognized as key players in the development of malignancy. They are a family of small non-coding RNAs (22 nt~30 nt) that can negatively regulate the expression of cancer-related genes by sequence selective targeting of mRNAs, leading to either mRNA translational repression or degradation. Lung cancer is the leading cause of cancer-related death worldwide with a substantially low survival rate. In this study, we analyzed the expression profile of miR-34c-3p in non-small cell lung cancer (NSCLC) tissues and cell lines, as its participation in some other types of cancer has been shown by previous reports. We found that miR-34c-3p was downregulated both in NSCLC tissues and cell lines. Overexpression of miR-34c-3p suppressed cell proliferation and colony formation and also limited migration and invasion in A549 cells. Furthermore, our results also shown miR-34c-3p reduction was associated with increased PAC1 expression levels in which miR-34c-3p downregulated PAC1 expression by recognizing and binding to specific binding sites in PAC1 3'-UTR. Taken together, our study implicates important roles of miR-34c-3p in NSCLC pathogenesis and implicates its potential application in cancer therapy.