Decreased expression of miR216a contributes to non-small-cell lung cancer progression.

The aim of the present study is to investigate the role and mechanism of miR216a in non-small-cell lung cancer (NSCLC). The expression of miR216a in NSCLC cell lines and from NSCLC patient specimens was measured by real-time qRT-PCR. The correlation between gene expression and patient survival was analyzed using Kaplan-Meier methods. The effects of miR216a on NSCLC cell growth and metastasis were examined both in vitro and in vivo by overexpressing or inhibiting miR216a. Finally, the effect of miR216a on chemoresistance was investigated by MTT assay and flow cytometry. miR216a expression was downregulated in specimens from patients with NSCLC compared with corresponding nontumor lung tissues. Clinical data indicate that decreased miR216a expression is inversely correlated with cancer stage, metastasis, and poor survival in patients with NSCLC. Our data also show that overexpression of miR216a suppresses NSCLC cell growth and metastasis, and enhances cisplatin-induced cell growth inhibition and apoptosis. In contrast, inhibition of miR216a stimulates NSCLC cell growth and metastasis, and suppresses cisplatin-induced cell growth inhibition and apoptosis. Furthermore, we demonstrate that miR216a exerts its role by directly targeting eIF4B and ZEB1. Our findings suggest that miR216a is a cancer suppressor miRNA and that overexpression of miR216a is a novel NSCLC treatment strategy. In addition, our clinical data indicate that miR216a may be a useful biomarker for predicting NSCLC progression.