Epithelial–Mesenchymal Transition Contributes to Docetaxel Resistance in Human Non-Small Cell Lung Cancer

Lung cancer is an aggressive malignancy with high morbidity and mortality. Chemotherapy has always been the principal treatment measure, but its acquired resistance becomes a critical problem. In the current study, we established a new docetaxel-resistant human non-small lung cancer (NSCLC) cell line A549/Docetaxel. The resistance index (RI) of A549/Docetaxel cells and A549 induced by TGF-β to docetaxel were 8.91 and 11.5, respectively. Compared to the parental A549 cells, the multiplication time of A549/Docetaxel was prolonged, the proportion of the cell cycle in the S phase decreased while that in the G(1) phase increased, and apoptotic rate was much lower. The morphology of the resistant cells eventuated epithelial–mesenchymal transition (EMT), which was confirmed by the higher expression of fibronectin, vimentin (mesenchymal markers), and lower expression of E-cadherin (epithelial marker) at mRNA and proteins levels. Furthermore, the representative markers for docetaxel resistance were examined, including ABCB1 (MDR1), Bcl-2, Bax, and tubulin, to figure out the mechanisms of the resistance of A549/Docetaxel. In summary, we have established a typical docetaxel-resistant human NSCLC cell line A549/Docetaxel, and it was suggested that the multidrug resistance of A549/Docetaxel was related to EMT.