The lncRNA MALAT1 contributes to non-small cell lung cancer development via modulating miR-124/STAT3 axis.

Abstract

lncRNAs can exert many biological effects in several cancer types. MALAT1 is a kind of lncRNA which is greatly overexpressed in several tumors including non-small cell lung cancer (NSCLC). However, the mechanism of MALAT1 in NSCLC still remains unclear. In our current study, we concentrated on the biological mechanism of MALAT1 in NSCLC. It was observed that MALAT1 was significantly upregulated in five human NSCLC cells including A549, H23, H522, H1299, and H460 cells compared to normal bronchial epithelial cell line 16HBE cells. On the contrary, miR-124 was remarkably downregulated, which indicated a potential negative correlation between miR-124 and MALAT1. MALAT1 inhibition can increase miR-124 expression in A549 and H460 cells. In addition, miR-124 mimics were able to repress MALAT1 expression and miR124 inhibitors can promote MALAT1 levels. Then it was found that shMALAT1 can inhibit NSCLC cell proliferation, colony formation and apoptosis, which can be reversed by miR-124 inhibitors. Bioinformatic analysis predicted the correlation between miR-124 and MALAT1. In addition, STAT3 was found to be a novel mRNA target of miR-124. Downregulation of MALAT1 can inhibit NSCLC development by enhancing miR-124 and decreasing STAT3 expression. We speculated that MALAT1can act as a competing endogenous lncRNA (ceRNA) to modulate miR-124/STAT3 in NSCLC. Taken these together, we revealed that MALAT1/miR-124/STAT3 was involved in NSCLC development.