miR-200c regulates crizotinib-resistant ALK-positive lung cancer cells by reversing epithelial-mesenchymal transition via targeting ZEB1.

Crizotinib is an orally administered drug for the treatment of patients with anaplastic lymphoma kinase (ALK)-positive locally advanced or metastatic non‑small cell lung cancer (NSCLC). Despite the impressive efficacy of crizotinib in the treatment of ALK‑positive lung cancer, acquired resistance eventually develops in the majority of patients. The microRNA (miR)‑200c reverses the resistance of lung cancer cells to various chemotherapeutic drugs and molecular targeted drugs, however, whether it can reverse the resistance of crizotinib remains unknown. The present study established a crizotinib resistant cell line (NCI‑2228/CRI), which was derived from the parental NCI‑2228 cell line by long‑term exposure to increasing concentrations of crizotinib. Through overexpression and suppression of miR‑200c expression, the characteristics associated with epithelial‑mesenchymal transition (EMT), including morphology, EMT marker proteins and cellular mobility, were investigated. Cell viability and invasion assays demonstrated that high expression of miR‑200c significantly inhibited the proliferation, migration and invasion of NCI‑2228 cells compared with the negative control. A luciferase reporter assay indicated that miR‑200c directly targeted the 3'‑untranslated region of zinc finger E‑box binding homeobox 1. Additionally, reverse transcription‑quantitative polymerase chain reaction analysis demonstrated that the mRNA levels of N‑cadherin and Vimentin were decreased in NCI‑2228 cells transfected with miR‑200c mimic compared with negative control cells, whereas the mRNA level of E‑cadherin was increased. In addition, EMT was reversed by miR‑200c, which suggests that miR‑200c may serve a role in mediating the sensitivity of NCI‑2228/CRI cells to crizotinib. The present study may therefore contribute to improving the sensitivity of ALK positive lung cancer cells to crizotinib.