The influence of miR-134 on cell growth by targeting epidermal growth factor receptor in non-small cell lung cancer

LIU Dongli; HE Xiaolong

doi:10.3969/j.issn.1009-0460.2016.12.002

Abstract：Objective To investigate the effect of microRNA-134 (miR-134) on suppressing the proliferation of non-small cell lung cancer (NSCLC) and the possible mechanism.Methods The expression levels of miR-134 in NSCLC cell lines (A549,H252) and human embryo lung WI38 cells were detected by real-time quantitative-PCR (QPCR).A549 and H252 cell lines were divided into miR-NC group,miR-134 group and blank control group,which were transfected with control-siRNA,miR-134 mimics and none,respectively.The proliferation in the three groups of A549 and H252 cells was detected by MTS assays 24,48,72,96 h after transfect.Cell apoptosis were detected by flow cytometry after 96 h.A luciferase reporter assay was performed to confirm whether epidermal growth factor receptor (EGFR) was a direct target of miR-134.The expression level of EGFR was detected by QPCR.Results The level of miR-134 was found down-regulated 85.91％ in A549 cells and 78.13％ in H252 cells comparing with it in WI38 cells (P＜ 0.05).MTS assays showed that miR-134 suppressed A549 and H252 cells proliferation significantly in a time-depended manner.Flow cytometry showed that the apoptotic rate of A549 and H252 cells increased to 226.31％ and 47.85％ respectively compared with blank control group (P＜0.05).A dual-luciferase reporter assay confirmed that EGFR was a direct target of miR-134 by reducing the activity of luciferase (P＜0.05).QPCR showed that after the transfect of miR-134 mimics,the expression of EGFR down-regulated 57.0％ in A549 cells and 35.0％ in H252 cells compared with blank control group (P＜ 0.01).Conclusion miR-134 is down-regulated in NSCLC and inhibitcs cells growth,as well as induces cell apoptosis by targeting EGFR in NSCLC.