Role of α7-nicotinic acetylcholine receptor in nicotine-induced invasion and epithelial-to-mesenchymal transition in human non-small cell lung cancer cells

// Chun Zhang 1, 2, * , Xu-Ping Ding 1, * , Qing-Nan Zhao 1, * , Xin-Jie Yang 1 , Shi-Min An 1 , Hao Wang 1 , Lu Xu 1 , Liang Zhu 1 , Hong-Zhuan Chen 1 1 Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China 2 Department of Pharmacy, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China * These authors have contributed equally to this work Correspondence to: Liang Zhu, email: jyzhul@shsmu.edu.cn Lu Xu, email: luxuluxu@yahoo.com Hong-Zhuan Chen, email: hongzhuan_chen@hotmail.com Keywords: α7-nAChR, nicotine, invasion, EMT, NSCLC Received: October 20, 2015 Accepted: June 29, 2016 Published: July 08, 2016 ABSTRACT Nicotine via nicotinic acetylcholine receptors (nAChRs) stimulates non-small cell lung cancer (NSCLC) cell invasion and epithelial to mesenchymal transition (EMT) which underpin the cancer metastasis. However, the receptor subtype-dependent effects of nAChRs on NSCLC cell invasion and EMT, and the signaling pathway underlying the effects remain not fully defined. We identified that nicotine induced NSCLC cell invasion, migration, and EMT; the effects were suppressed by pharmacological intervention using α7-nAChR selective antagonists or by genetic intervention using α7-nAChR knockdown via RNA inference. Meanwhile, nicotine induced activation of MEK/ERK signaling in NSCLC cells; α7-nAChR antagonism or MEK/ERK signaling pathway inhibition suppressed NSCLC cell invasion and EMT marker expression. These results indicate that nicotine induces NSCLC cell invasion, migration, and EMT; the effects are mediated by α7-nAChRs and involve MEK/ERK signaling pathway. Delineating the effect of nicotine on the NSCLC cell invasion and EMT at receptor subtype level would improve the understanding of cancer biology and offer potentials for the exploitation of selective ligands for the control of the cancer metastasis.