Terfenadine combined with epirubicin impedes the chemo-resistant human non-small cell lung cancer both in vitro and in vivo through EMT and Notch reversal.

The acquired resistance of non-small cell lung cancer (NSCLC) to taxanes eventually leads to the recurrence and metastasis of tumours. Thus, the development of therapeutic strategies based on the mechanisms by which cells acquire resistance to prolong their survival rate in chemotherapy drug treatment failure patients are warranted. In this study, we found that the resistant cells acquired increased migratory and invasive capabilities, and this transformation was correlated with epithelial-mesenchymal transition (EMT) and Notch pathway deregulation in the resistant cells. Finally, we reported for the first time that terfenadine augmented the effect of epirubicin (EPI) better than Taxol and cisplatin (DDP) by inhibiting migration, invasion, and the EMT phenotype, and the combination therapy also reversed Notch signalling pathway and enhanced the accumulation of fluorescent P-gp substrate rhodamine 123 (Rh123). Similar activities of terfenadine on EPI were observed in xenografts. All of our results confirmed that terfenadine combined with EPI synergistically inhibits the growth and metastatic processes of resistant cells both in vitro and in vivo. Therefore, terfenadine or its derivatives are a promising approach for the clinical challenge of resistance in patients with advanced NSCLC.