title: Role of cMET expression in non-small-cell lung cancer patients treated with EGFR tyrosine kinase inhibitors.
abstract: BACKGROUND
  Approximately 10% of unselected non-small-cell lung cancer (NSCLC) patients responded to the epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. However, resistance mechanisms are not well understood. We evaluated several potential biological markers of intrinsic EGFR-TKIs-resistance in NSCLC.
  
  
  METHODS
  pAKT, pERK, cSRC, E-cadherin, cMET[pY1003], cMET[pY1230/1234/1235], and cMET[pY1349] immunohistochemistry, cMET FISH analysis, and EGFR-, KRAS-, and cMET mutation analysis were carried out on tumor samples from 51 gefitinib-treated NSCLC patients. Biological parameters and survival end points were compared by univariate and multivariate analyses. cMET expression was also investigated in two additional series of patients. The in vitro antiproliferative activity of gefitinib alone or in combination with hepatocyte growth factor and the cMET antibody DN-30 was assessed in NSCLC cells.
  
  
  RESULTS
  EGFR19 deletion and pAKT expression were significantly associated with response (P < 0.0001) and longer time to progression (TTP) (P = 0.007), respectively. Strong cMET[pY1003] membrane immunoreactivity was expressed in 6% of 149 tumors analyzed and was significantly associated with progressive disease (P = 0.019) and shorter TTP (P = 0.041). In vitro, the DN-30 combination synergistically (CI < 1) enhanced gefitinib-induced growth inhibition in all cMET[pY1003]-expressing cell lines studied.
  
  
  CONCLUSIONS
  Activated cMET[pY1003] appears to be a marker of primary gefitinib resistance in NSCLC patients. cMET may be a target in treatment of NSCLC.
authors.affiliation: Department of Medical Oncology and Hematology, Istituto Clinico Humanitas, Rozzano, Milan, Italy.
authors.forename: P A
authors.initials: PA
authors.lastname: Zucali
authors.forename: M G
authors.initials: MG
authors.lastname: Ruiz
authors.forename: E
authors.initials: E
authors.lastname: Giovannetti
authors.forename: A
authors.initials: A
authors.lastname: Destro
authors.forename: M
authors.initials: M
authors.lastname: Varella-Garcia
authors.forename: K
authors.initials: K
authors.lastname: Floor
authors.forename: G L
authors.initials: GL
authors.lastname: Ceresoli
authors.forename: J A
authors.initials: JA
authors.lastname: Rodriguez
authors.forename: I
authors.initials: I
authors.lastname: Garassino
authors.forename: P
authors.initials: P
authors.lastname: Comoglio
authors.forename: M
authors.initials: M
authors.lastname: Roncalli
authors.forename: A
authors.initials: A
authors.lastname: Santoro
authors.forename: G
authors.initials: G
authors.lastname: Giaccone
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics* / Q000401:mortality; D015331:Cohort Studies; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D005260:Female; D000077156:Gefitinib; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation / Q000187:drug effects; D009367:Neoplasm Staging; D011336:Probability; D016016:Proportional Hazards Models; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage; D011505:Protein-Tyrosine Kinases / Q000187:drug effects / Q000235:genetics*; D011799:Quinazolines / Q000008:administration & dosage*; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D000077156:Gefitinib