miR-34b inhibits the migration/invasion and promotes apoptosis of non-small-cell lung cancer cells by YAF2.

ABSTRACT

OBJECTIVE: Lung cancer is the leading cause of cancer death in the world and microRNAs (miRNA) have been found to be involved in the initiation and development of cancer by acting as potential oncogenes or tumor suppressor genes. PATIENTS AND METHODS: In this study, we investigated the expression of miR-34b in non-small cell lung cancer (NSCLC) patients and discussed the molecular mechanism of miR-34b in the invasion and migration of A549 cells in vitro. RESULTS: Our results showed that miR-34b was significantly down-regulated in primary cancer tissues when compared with the normal lung tissues. The over-expression of miR-34b inhibited migration and invasion, and promoted apoptosis of A549 lung cancer cells. Furthermore, Luciferase reporter assay validated YY1-associated factor 2 (YAF2) as a direct target of miR-34b and YAF2 expression was significantly increased in clinical NSCLC tissue samples. In addition, the over-expression of miR-34b inhibited YAF2, p-Jak2, p-STAT3 and MMP2 protein expression and promoted caspase 3 protein expression in cancer cells. CONCLUSIONS: Our results suggest that miR-34b may inhibit migration and invasion of NSCLC cells by targeting YAF2. Thus, our findings provide new insight into the molecular mechanisms of lung cancer metastasis and miR-34b may serve as a potential target in the treatment of human lung cancer.