title: Oncogenic activation of the RAS/RAF signaling pathway impairs the response of metastatic colorectal cancers to anti-epidermal growth factor receptor antibody therapies.
abstract: Monoclonal antibodies (mAbs) against the extracellular domain of the epidermal growth factor receptor (EGFR) have been introduced for the treatment of metastatic colorectal cancer (mCRC). We have reported recently that increased copy number of the EGFR can predict response to anti-EGFR mAbs and that patients might be selected for treatment based on EGFR copy number. Here, we show that mutations activating the RAS/RAF signaling pathway are also predictive and prognostic indicators in mCRC patients, being inversely correlated with response to anti-EGFR mAbs. In cellular models of CRCs, activation of the RAS signaling pathway by introduction of an activated K-RAS allele (Gly(12)Val) impairs the therapeutic effect of anti-EGFR mAbs. In cancer cells carrying constitutively active RAS, the pharmacologic inhibition of the mitogen-activated protein kinase (MAPK) signaling cascade improves anti-EGFR treatment based on mAbs. These results have implications for the identification of patients who are likely to respond to anti-EGFR treatment. They also provide the rationale for combination therapies, targeted simultaneously to the EGFR and RAS/RAF/MAPK signaling pathways in CRC patients.
authors.affiliation: Laboratory of Molecular Genetics, Institute for Cancer Research and Treatment, University of Torino Medical School, Candiolo, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Benvenuti
authors.forename: Andrea
authors.initials: A
authors.lastname: Sartore-Bianchi
authors.forename: Federica
authors.initials: F
authors.lastname: Di Nicolantonio
authors.forename: Carlo
authors.initials: C
authors.lastname: Zanon
authors.forename: Mauro
authors.initials: M
authors.lastname: Moroni
authors.forename: Silvio
authors.initials: S
authors.lastname: Veronese
authors.forename: Salvatore
authors.initials: S
authors.lastname: Siena
authors.forename: Alberto
authors.initials: A
authors.lastname: Bardelli
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000628:therapy; D066246:ErbB Receptors / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics; D008297:Male; D008875:Middle Aged; D000077544:Panitumumab; D048490:raf Kinases / Q000235:genetics* / Q000378:metabolism*; D018631:ras Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000077544:Panitumumab; D066246:ErbB Receptors; D048490:raf Kinases; D018631:ras Proteins; D000068818:Cetuximab