Upregulation of microRNA-451 increases cisplatin sensitivity of non-small cell lung cancer cell line (A549)

Abstract
Background: Recently, miR-451 as a tumor suppressor has been reported in other studies. However, whether miR-451 can affect the sensitivity of non-small cell lung cancer (NSCLC) cells to cisplatin (DDP) remains unclear. The aim of this study is to evaluate the roles of miR-451 in the sensitivity of NSCLC cells to DDP. Methods: Quantitative RT-PCR assay was performed to detect the expression of miR-451 in 10 pairs of NSCLC and noncancerous tissue samples. pcDNA-GW/EmGFP-miR-451 was stably transfected into NSCLC cell line (A549). Then, the effects of miR-451 upregulation on growth, colony formation and apoptosis of A549 cells were investigated. Finally, the effects of miR-451 upregulation on in vitro and in vivo sensitivity of A549 cells of DDP were also determined. Results: The level of miR-451 expression in NSCLC tissues was significantly higher than that in corresponding noncancerous tissues. Ectopic overexpression of miR-451 could significantly inhibit growth and induce apoptosis of A549 cells. Moreover, ectopic overexpression of miR-451 could sensitize A549 cells to DDP possibly by increasing DDP-induced apoptosis which might be associated with the inactivation of Akt signaling pathway. Conclusions: This study demonstrated for the first time that combination of DDP application with miR-451 upregulation might be a potential strategy for the treatment of human NSCLC.