title: Genetic predictors of MEK dependence in non-small cell lung cancer.
abstract: Hyperactivated extracellular signal-regulated kinase (ERK) signaling is common in human cancer and is often the result of activating mutations in BRAF, RAS, and upstream receptor tyrosine kinases. To characterize the mitogen-activated protein kinase/ERK kinase (MEK)/ERK dependence of lung cancers harboring BRAF kinase domain mutations, we screened a large panel of human lung cancer cell lines (n = 87) and tumors (n = 916) for BRAF mutations. We found that non-small cell lung cancers (NSCLC) cells with both V600E and non-V600E BRAF mutations were selectively sensitive to MEK inhibition compared with those harboring mutations in epidermal growth factor receptor (EGFR), KRAS, or ALK and ROS kinase fusions. Supporting its classification as a "driver" mutation in the cells in which it is expressed, MEK inhibition in (V600E)BRAF NSCLC cells led to substantial induction of apoptosis, comparable with that seen with EGFR kinase inhibition in EGFR mutant NSCLC models. Despite high basal ERK phosphorylation, EGFR mutant cells were uniformly resistant to MEK inhibition. Conversely, BRAF mutant cell lines were resistant to EGFR inhibition. These data, together with the nonoverlapping pattern of EGFR and BRAF mutations in human lung cancer, suggest that these lesions define distinct clinical entities whose treatment should be guided by prospective real-time genotyping. To facilitate such an effort, we developed a mass spectrometry-based genotyping method for the detection of hotspot mutations in BRAF, KRAS, and EGFR. Using this assay, we confirmed that BRAF mutations can be identified in a minority of NSCLC tumors and that patients whose tumors harbor BRAF mutations have a distinct clinical profile compared with those whose tumors harbor kinase domain mutations in EGFR.
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
authors.forename: Christine A
authors.initials: CA
authors.lastname: Pratilas
authors.forename: Aphrothiti J
authors.initials: AJ
authors.lastname: Hanrahan
authors.forename: Ensar
authors.initials: E
authors.lastname: Halilovic
authors.forename: Yogindra
authors.initials: Y
authors.lastname: Persaud
authors.forename: Junichi
authors.initials: J
authors.lastname: Soh
authors.forename: Dhananjay
authors.initials: D
authors.lastname: Chitale
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Shigematsu
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Ayana
authors.initials: A
authors.lastname: Sawai
authors.forename: Manickam
authors.initials: M
authors.lastname: Janakiraman
authors.forename: Barry S
authors.initials: BS
authors.lastname: Taylor
authors.forename: William
authors.initials: W
authors.lastname: Pao
authors.forename: Shinichi
authors.initials: S
authors.lastname: Toyooka
authors.forename: Marc
authors.initials: M
authors.lastname: Ladanyi
authors.forename: Adi
authors.initials: A
authors.lastname: Gazdar
authors.forename: Neal
authors.initials: N
authors.lastname: Rosen
authors.forename: David B
authors.initials: DB
authors.lastname: Solit
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D020935:MAP Kinase Signaling System; D008297:Male; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins / Q000235:genetics
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D066246:ErbB Receptors; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D048049:Extracellular Signal-Regulated MAP Kinases; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins