miR-133b Inhibits Cell Growth, Migration, and Invasion by Targeting MMP9 in Non-Small Cell Lung Cancer

Although increasing evidence indicates that the deregulation of microRNAs (miRNAs) contributes to tumorigenesis and invasion, little is known about the role of miR-133b in human non-small cell lung cancer (NSCLC). In the present study, we revealed that the introduction of miR-133b dramatically suppressed NSCLC cell growth, migration, and invasion in vitro. On the contrary, miR-133b inhibitors promoted cell growth, migration, and invasion in vitro. Further studies revealed that matrix metallopeptidase 9 (MMP9) is a direct target gene of miR-133b. Silencing MMP9 inhibited cell growth, migration, and invasion of NSCLC cells, which was consistent with the effect of miR-133b overexpression. In clinical specimens, reduced miR-133b was an unfavorable factor and negatively correlated with MMP9 expression. Our studies demonstrate that miR-133b inhibits cell growth, migration, and invasion by targeting MMP9 in NSCLC.