Upregulated lncRNA H19 promotes non-small cell lung cancer cell proliferation through miR-138/PDK1 axis

Long non-coding RNA (lncRNA) H19 was reported to be aberrantly expressed and implicated in non-small cell lung cancer (NSCLC). However, the regulation of NSCLC progression by H19 was not well understood. In this study, we found that the expression level of H19 was obviously increased, but miR-138 was decreased in NSCLC tissues and NSCLC cells including A549, H1299 and H460 cells. Upregulation of H19 promotes cell proliferation ability in A549 and H460 cells, while downregulation of H19 did the opposite. H19 represses miR138 expression and H19 expression level was negatively correlated with miR-138 expression level in NSCLC tissues. Moreover, overexpression of mutant H19 (Mut-H19) has no effect on miR-138 expression in A549 and H460 cells. Dual luciferase reporter assay showed that PDK1 was a target gene of miR-138. Overexpression of H19 attenuated the inhibitory effect of miR-138 on PDK1 protein expression. The inhibition of NSCLC cell proliferation induced by H19 knockdown required the activity of miR-138, and could be reversed by overexpression of PDK1. Overall, we concluded that H19 upregulates the expression of PDK1 through downregulation of miR-138 to promote NSCLC cell proliferation. H19 could potentially be employed as a therapeutic target for the treatment of NSCLC.