title: Epithelial-mesenchymal transition leads to crizotinib resistance in H2228 lung cancer cells with EML4-ALK translocation.
abstract: Epithelial-mesenchymal transition (EMT) is associated with reduced sensitivity to many chemotherapeutic drugs, including EGFR tyrosine kinase inhibitors. Here, we investigated if this reduced sensitivity also contributes to resistance to crizotinib, an ALK inhibitor of lung cancer that exhibits the EML4-ALK translocation. We established a crizotinib-resistant subline (H2228/CR), which was derived from the parental H2228 cell line by long-term exposure to increasing concentrations of crizotinib. Characteristics associated with EMT, including morphology, EMT marker proteins, and cellular mobility, were analyzed. Compared with H2228 cells, the growth of H2228/CR cells was independent of EML4-ALK, and H2228/CR cells showed cross-resistance to TAE-684 (a second-generation ALK inhibitor). Phenotypic changes to the spindle-cell shape were noted in H2228/CR cells, which were accompanied by a decrease in E-cadherin and increase in vimentin and AXL. In addition, H2228/CR cells showed increased secretion and expression of TGF-β1. Invasion and migration capabilities were dramatically increased in H2228/CR cells. Applying TGF-β1 treatment to parental H2228 cells for 72 h induced reversible EMT, leading to crizotinib resistance, but this was reversed by the removal of TGF-β1. Suppression of vimentin in H2228/CR cells by siRNA treatment restored sensitivity to crizotinib. Furthermore, these resistant cells remained highly sensitive to the Hsp90 inhibitors, similar to the parental H2228 cells. In conclusion, we suggest EMT is possibly involved in acquired resistance to crizotinib, and that HSP90 inhibitors could be a promising option for the treatment of EMT.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Hyeong Ryul
authors.initials: HR
authors.lastname: Kim
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Kim
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Choi
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Choi
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Rho
authors.forename: Jae Cheol
authors.initials: JC
authors.lastname: Lee
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D000077547:Crizotinib; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D016716:PC12 Cells; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011720:Pyrazoles / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D014178:Translocation, Genetic
chemical_list: C522504:EML4-ALK fusion protein, human; D015514:Oncogene Proteins, Fusion; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011725:Pyridines; D000077547:Crizotinib
keywords: ALK; Epithelial–mesenchymal transition; Lung cancer; Resistance