title: An Activating KIT Mutation Induces Crizotinib Resistance in ROS1-Positive Lung Cancer.
abstract: Patients with non-small cell lung cancer (NSCLC) harboring ROS proto-oncogene 1, receptor tyrosine kinase gene (ROS1) chromosomal rearrangements benefit from treatment with the ROS1 inhibitor crizotinib. Limited data exist on the spectrum of resistance mechanisms in ROS1-positive NSCLC. To delineate mechanisms of acquired resistance, we analyzed biopsy samples of tumor lesions that progressed while patients were receiving crizotinib.
  
  
  
  An activating mutation in the KIT proto-oncogene receptor tyrosine kinase (KIT) (p.D816G) was identified by SNaPshot sequencing in a tumor sample from a patient with ROS1-positive NSCLC identified by fluorescence in situ hybridization whose disease progressed after initial response to crizotinib. In vitro studies included evaluation of KIT mRNA expression by quantitative reverse-transcriptase polymerase chain reactions, transduction of Ba/F3 cells and NSCLC cell lines with KIT-expressing lentiviral plasmids, immunoblotting, and cellular proliferation assays.
  
  
  
  KIT(D816G) is an activating mutation that induces autophosphorylation and cell proliferation. Expression of the mutant KIT(D816G) receptor in ROS1-positive NSCLC cell lines led to constitutively activated KIT as measured by phosphorylation of the KIT receptor. Expression of the KIT(D816G) rendered the HCC78 and CUTO2 cell lines resistant to crizotinib, and only dual inhibition of ROS1 and KIT with crizotinib and ponatinib could resensitize the cells to inhibition of proliferation. The oncogenic switch observed in ROS1-positive cell lines was not immediate and required pharmacologic inactivation of ROS1.
  
  
  
  Activation of KIT by a gain-of-function somatic mutation is a novel mechanism of resistance to crizotinib in ROS1-rearranged NSCLC. This bypass signaling pathway serves as a ROS1-independent mechanism of resistance, similarly to previously identified epidermal growth factor receptor or Kirsten rat sarcoma viral oncogene homolog/neuroblastoma RAS viral oncogene homolog signaling pathways, and can potentially be targeted by KIT inhibitors.
authors.affiliation: Department of Oncology and Radiotherapy, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Rafal
authors.initials: R
authors.lastname: Dziadziuszko
authors.affiliation: Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado.
authors.forename: Anh T
authors.initials: AT
authors.lastname: Le
authors.affiliation: Department of Oncology and Radiotherapy, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Wrona
authors.affiliation: Department of Oncology and Radiotherapy, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Jassem
authors.affiliation: Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado.
authors.forename: D Ross
authors.initials: DR
authors.lastname: Camidge
authors.affiliation: Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado; Department of Pathology, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado.
authors.forename: Marileila
authors.initials: M
authors.lastname: Varella-Garcia
authors.affiliation: Department of Pathology, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado.
authors.forename: Dara L
authors.initials: DL
authors.lastname: Aisner
authors.affiliation: Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado. Electronic address: robert.doebele@ucdenver.edu.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Doebele
mesh_terms: D000328:Adult; D002289:Carcinoma, Non-Small-Cell Lung / Q000737:chemistry / Q000188:drug therapy* / Q000235:genetics; D045744:Cell Line, Tumor; D000077547:Crizotinib; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000235:genetics; D009154:Mutation; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000032:analysis* / Q000037:antagonists & inhibitors; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000037:antagonists & inhibitors; D019009:Proto-Oncogene Proteins c-kit / Q000037:antagonists & inhibitors / Q000235:genetics*; D011720:Pyrazoles / Q000627:therapeutic use*; D011725:Pyridines / Q000627:therapeutic use*
chemical_list: C000715470:MAS1 protein, human; D047428:Protein Kinase Inhibitors; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D011720:Pyrazoles; D011725:Pyridines; D000077547:Crizotinib; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit; C062333:ROS1 protein, human
keywords: Bypass signaling; Drug resistance; KIT; NSCLC; ROS1; Tyrosine kinase inhibitor