Preclinical modeling of EGFR inhibitor resistance in head and neck cancer

Cancer Biol Ther. 2012 Aug;13(10):935-45. doi: 10.4161/cbt.20846. Epub 2012 Aug 1.

Abstract

The epidermal growth factor receptor (EGFR) is widely expressed in head and neck squamous cell carcinomas (HNSCC) and can activate many growth and survival pathways within tumor cells. Despite ubiquitous EGFR expression, therapies targeting the receptor are only modestly effective in the treatment of HNSCC. A consistent mechanism of resistance to EGFR targeting agents has not yet been identified in HNSCC likely due, in part, to the paucity of preclinical models. We assessed the in vitro and in vivo responses of a panel of 10 genotypically validated HNSCC cell lines to the EGFR inhibitors erlotinib and cetuximab to determine their validity as models of resistance to these agents. We defined a narrow range of response to erlotinib in HNSCC cells in vitro and found a positive correlation between EGFR protein expression and erlotinib response. We observed cross-sensitivity in one HNSCC cell line, 686LN, between erlotinib and cetuximab in vivo. We attempted to generate models of cetuximab resistance in HNSCC cell line-derived xenografts and heterotopic tumorgrafts generated directly from primary patient tumors. While all 10 HNSCC cell line xenografts tested were sensitive to cetuximab in vivo, heterotopic patient tumorgrafts varied in response to cetuximab indicating that these models may be more representative of clinical responses. These studies demonstrate the limitations of using HNSCC cell lines to reflect the heterogeneous clinical responses to erlotinib and cetuximab, and suggest that different approaches including heterotopic tumorgrafts may prove more valuable to elucidate mechanisms of clinical resistance to EGFR inhibitors in HNSCC.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / administration & dosage
  • Antibodies, Monoclonal / pharmacology*
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / pharmacology*
  • Carcinoma, Squamous Cell / drug therapy*
  • Carcinoma, Squamous Cell / metabolism
  • Cell Line, Tumor
  • Cetuximab
  • Drug Resistance, Neoplasm / drug effects
  • ErbB Receptors / antagonists & inhibitors*
  • ErbB Receptors / metabolism
  • Erlotinib Hydrochloride
  • Head and Neck Neoplasms / drug therapy*
  • Head and Neck Neoplasms / metabolism
  • Humans
  • Inhibitory Concentration 50
  • Mice
  • Mice, Nude
  • Protein Kinase Inhibitors / administration & dosage
  • Protein Kinase Inhibitors / pharmacology*
  • Quinazolines / administration & dosage
  • Quinazolines / pharmacology*
  • Squamous Cell Carcinoma of Head and Neck
  • Tumor Burden / drug effects
  • Xenograft Model Antitumor Assays

Substances

  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents
  • Protein Kinase Inhibitors
  • Quinazolines
  • Erlotinib Hydrochloride
  • ErbB Receptors
  • Cetuximab