MicroRNA-7 inhibits cell proliferation, migration and invasion in human non-small cell lung cancer cells by targeting FAK through ERK/MAPK signaling pathway

// Qi Cao 1, * , Zheng-Dao Mao 1, * , Yu-Jia Shi 1 , Yi Chen 1 , Yun Sun 1 , Qian Zhang 1 , Lei Song 1 , Li-Ping Peng 1 1 Department of Respiratory Medicine, Affiliated Changzhou No.2 People’s Hospital, Nanjing Medical University, Changzhou 213003, P.R. China * This authors have contributed equally to this work Correspondence to: Qian Zhang, email: profzhangqian@126.com Keywords: non-small cell lung cancer, microRNA-7, FAK, ERK/MAPK signaling pathway, cell proliferation Received: April 23, 2016     Accepted: September 02, 2016     Published: October 15, 2016 ABSTRACT Objective: To investigate the effects of microRNA-7 (miR-7) on the proliferation, migration and invasion of non-small cell lung cancer NSCLC) cells by targeting FAK through ERK/MAPK signaling pathway. Methods: NSCLC tissues and adjacent normal tissues were obtained from 160 NSCLC patients after operation. NSCLC cell lines (A549, H1299 and H1355) and a normal human fetal lung fibroblast cell line (MRC-5) were obtained. NSCLC cells were assigned into miR-7 inhibitors, miR-7 mimics, blank, miR-7 mimics control, miR-7 inhibitors control, FAK siRNA and miR-7 inhibitors + FAK siRNA groups. The expressions of miR-7 and FAK mRNA in tissues and cell lines were detected by qRT-PCR and Western-Blotting. Cell proliferation, migration and invasion were detected by MTT assay, wound scratch assay and Transwell assay. Results: Compared with adjacent normal tissues, miR-7 expression was down-regulated, but the mRNA and protein expressions of FAK, ERK and MAPK were up-regulated. Compared with the blank and mimics control groups, miR-7 significantly increased but FAK, ERK and MAPK expressions decreased in miR-7 mimics and FAK siRNA groups. Cell proliferation, migration and invasion were inhibited in the miR-7 mimics and FAK siRNA groups, while opposite regarding miR-7 inhibitors group. Conclusion: The miR-7 can inhibit the activation of ERK/MAPK signaling pathway by down-regulating FAK expression, thereby suppressing the proliferation, migration and invasion of NSCLC cells. The miR-7 and its target gene FAK may be novel targets for the diagnosis and treatment of NSCLC.