Mass spectrometry mapping of epidermal growth factor receptor phosphorylation related to oncogenic mutations and tyrosine kinase inhibitor sensitivity

J Proteome Res. 2011 Jan 7;10(1):305-19. doi: 10.1021/pr1006203. Epub 2010 Dec 3.


The epidermal growth factor receptor (EGFR) plays an important role in cancer by activating downstream signals important in growth and survival. Inhibitors of EGFR are frequently selected as treatment for cancer including lung cancer. We performed an unbiased and comprehensive search for EGFR phosphorylation events related to somatic activating mutations and EGFR inhibitor (erlotinib) sensitivity. EGFR immunoprecipitation combined with high resolution liquid chromatography-mass spectrometry and label free quantitation characterized EGFR phosphorylation. Thirty (30) phosphorylation sites were identified including 12 tyrosine (pY), 12 serine (pS), and 6 threonine (pT). Site-specific phosphorylation was monitored by comparing ion signals from the corresponding unmodified peptide. Phosphorylation sites related to activating mutations in EGFR as well as sensitivity to erlotinib were identified using 31 lung cancer cell lines. We identified three sites (pY1092, pY1110, pY1172) correlated with activating mutations and three sites (pY1110, pY1172, pY1197) correlated with erlotinib sensitivity. Five sites (pT693, pY1092, pY1110, pY1172, and pY1197) were inhibited by erlotinib in concentration-dependent manner. Erlotinib sensitivity was confirmed using liquid chromatography coupled to multiple reaction monitoring (LC-MRM) and quantitative Western blotting. This LC-MS/MS strategy can quantitatively assess site-specific EGFR phosphorylation and can identify relationships between somatic mutations or drug sensitivity and protein phosphorylation.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Western
  • Carcinoma, Non-Small-Cell Lung
  • Cell Line, Tumor
  • Chromatography, Liquid
  • Drug Resistance, Neoplasm / drug effects*
  • ErbB Receptors / antagonists & inhibitors
  • ErbB Receptors / chemistry
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Erlotinib Hydrochloride
  • Immunoprecipitation
  • Lung Neoplasms
  • Mice
  • Mice, Nude
  • Molecular Sequence Data
  • Peptide Fragments
  • Peptide Mapping / methods*
  • Phosphorylation / drug effects
  • Phosphorylation / genetics
  • Protein Kinase Inhibitors / pharmacology*
  • Protein-Tyrosine Kinases* / antagonists & inhibitors
  • Protein-Tyrosine Kinases* / metabolism
  • Quinazolines / pharmacology
  • Reproducibility of Results
  • Tandem Mass Spectrometry / methods
  • Xenograft Model Antitumor Assays


  • Peptide Fragments
  • Protein Kinase Inhibitors
  • Quinazolines
  • Erlotinib Hydrochloride
  • ErbB Receptors
  • Protein-Tyrosine Kinases