title: Epidermal growth factor receptor cooperates with Src family kinases in acquired resistance to cetuximab.
abstract: The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that plays a major role in oncogenesis. Cetuximab is an EGFR-blocking antibody that is FDA approved for use in patients with metastatic colorectal cancer (mCRC) and head and neck squamous cell carcinoma (HNSCC). Although cetuximab has shown strong clinical benefit for a subset of cancer patients, most become refractory to cetuximab therapy. We reported that cetuximab-resistant NSCLC line NCI-H226 cells have increased steady-state expression and activity of EGFR secondary to altered trafficking/degradation and this increase in EGFR expression and activity lead to hyper-activation of HER3 and down stream signals to survival. We now present data that Src family kinases (SFKs) are highly activated in cetuximab-resistant cells and enhance EGFR activation of HER3 and PI(3)K/Akt. Studies using the Src kinase inhibitor dasatinib decreased HER3 and PI(3)K/Akt activity. In addition, cetuximab-resistant cells were resensitized to cetuximab when treated with dasatinib. These results indicate that SFKs and EGFR cooperate in acquired resistance to cetuximab and suggest a rationale for clinical strategies that investigate combinatorial therapy directed at both the EGFR and SFKs in patients with acquired resistance to cetuximab.
authors.affiliation: Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA. dlwheeler@wisc.edu
authors.forename: Deric L
authors.initials: DL
authors.lastname: Wheeler
authors.forename: Mari
authors.initials: M
authors.lastname: Iida
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Kruser
authors.forename: Meghan M
authors.initials: MM
authors.lastname: Nechrebecki
authors.forename: Emily F
authors.initials: EF
authors.lastname: Dunn
authors.forename: Eric A
authors.initials: EA
authors.lastname: Armstrong
authors.forename: Shyhmin
authors.initials: S
authors.lastname: Huang
authors.forename: Paul M
authors.initials: PM
authors.lastname: Harari
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D000068818:Cetuximab; D000069439:Dasatinib; D019008:Drug Resistance, Neoplasm; D004359:Drug Therapy, Combination; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011743:Pyrimidines / Q000627:therapeutic use; D020893:Receptor, ErbB-3 / Q000378:metabolism; D013844:Thiazoles / Q000627:therapeutic use; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D013844:Thiazoles; D019869:Phosphatidylinositol 3-Kinases; C512478:EGFR protein, human; D066246:ErbB Receptors; D020893:Receptor, ErbB-3; D019061:src-Family Kinases; D051057:Proto-Oncogene Proteins c-akt; D000068818:Cetuximab; D000069439:Dasatinib