MicroRNA-455 suppresses non-small cell lung cancer through targeting ZEB1.

MicroRNA-455 (miRNA-455), which is downregulated in human cancer, potently mediates the multiple steps of carcinogenesis. However, the role of miR-455 in non-small cell lung cancer (NSCLC) carcinogenesis remains unclear. In present study, we determined the mature miRNA-455 expression in NSCLC tissues and cells by real-time PCR. Follow-up studies examined the effects of a miR-455 mimic (gain of function) on cell proliferation, migration, and invasion. Our data indicate that miR-455 was significantly down-regulated in NSCLC cell lines and tissues. In functional assays, overexpression of miR-455 suppressed the proliferation, migration, and invasion of NSCLC cell lines. Data from reporter assays showed that miR-455 directly binds to 3'UTR of ZEB1 and suppresses the endogenous level of ZEB1 protein expression. Furthermore, overexpression of ZEB1 reverses miR-455-suppressed malignant phenotype of NSCLC cells. Moreover, we found that upregulation of ZEB1 expression is inversely associated with miR-455 expression in NSCLC tissues. Taken together, miR-455 as an anti-oncogene in non-small cell lung cancer through up-regulation of ZEB1 and serve as a potential therapeutic target in NSCLC.