[Nicotine Induced Lung Cancer Cells Epithelial-mesenchymal Transition 
and Promote Its Vitro Invasion Potential].

BACKGROUND:Our previous study found that nicotine could induce lung cancer cell epithelial-mesenchymal transition (EMT). The aim of this study is to explore the relationship between nicotine-induced EMT and lung cancer invasion and metastasis. METHODS:Real-time PCR and Western blot were used to detect the expression changes of EMT-related markers, E-cadherin and Vimentin, in A549 lung cancer cells treated with nicotine; The transposition of β-catenin protein expression was determined by immunofluorescence; Scratch test and Transwell invasion assay were used to detect the effects of nicotine on lung cancer cell migration and invasion. RESULTS:Nicotine can significantly down-regulate the expressional level of E-cadherin mRNA and protein of A549 cells in a manner of dose and time-dependent (P<0.01, P<0.01); Nicotine can significantly up-regulate the expressional level of Vimentin mRNA and protein of A549 cells in a manner of dose and time-dependent (P<0.01, P<0.01); Immunofluorescence results showed that β-catenin protein was significantly transfered to nucleus; Scratch test and Transwell assay showed that Nicotine could remarkably increase the migration and invasion potential of lung cancer cells (P<0.01, P<0.01). CONCLUSIONS:Nicotine can induce cancer cells EMT, and promote the invasion and metastasis ability of lung cancer cells.