Adaptive responses to dasatinib-treated lung squamous cell cancer cells harboring DDR2 mutations

Cancer Res. 2014 Dec 15;74(24):7217-7228. doi: 10.1158/0008-5472.CAN-14-0505. Epub 2014 Oct 27.

Abstract

DDR2 mutations occur in approximately 4% of lung squamous cell cancer (SCC) where the tyrosine kinase inhibitor dasatinib has emerged as a new therapeutic option. We found that ERK and AKT phosphorylation was weakly inhibited by dasatinib in DDR2-mutant lung SCC cells, suggesting that dasatinib inhibits survival signals distinct from other oncogenic receptor tyrosine kinases (RTK) and/or compensatory signals exist that dampen dasatinib activity. To gain better insight into dasatinib's action in these cells, we assessed altered global tyrosine phosphorylation (pY) after dasatinib exposure using a mass spectrometry-based quantitative phosphoproteomics approach. Overlaying protein-protein interaction relationships upon this dasatinib-regulated pY network revealed decreased phosphorylation of Src family kinases and their targets. Conversely, dasatinib enhanced tyrosine phosphorylation in a panel of RTK and their signaling adaptor complexes, including EGFR, MET/GAB1, and IGF1R/IRS2, implicating a RTK-driven adaptive response associated with dasatinib. To address the significance of this observation, these results were further integrated with results from a small-molecule chemical library screen. We found that dasatinib combined with MET and insulin-like growth factor receptor (IGF1R) inhibitors had a synergistic effect, and ligand stimulation of EGFR and MET rescued DDR2-mutant lung SCC cells from dasatinib-induced loss of cell viability. Importantly, we observed high levels of tyrosine-phosphorylated EGFR and MET in a panel of human lung SCC tissues harboring DDR2 mutations. Our results highlight potential RTK-driven adaptive-resistant mechanisms upon DDR2 targeting, and they suggest new, rationale cotargeting strategies for DDR2-mutant lung SCC.

Publication types

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

MeSH terms

  • Adaptive Immunity / drug effects
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Dasatinib
  • Discoidin Domain Receptors
  • Drug Resistance, Neoplasm / genetics
  • Drug Resistance, Neoplasm / immunology
  • Drug Synergism
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / immunology
  • Lung Neoplasms / pathology
  • Mutation
  • Neoplasms, Squamous Cell / drug therapy*
  • Neoplasms, Squamous Cell / immunology
  • Neoplasms, Squamous Cell / pathology
  • Proto-Oncogene Proteins c-ret / metabolism
  • Pyrimidines / administration & dosage*
  • Receptor Protein-Tyrosine Kinases / genetics*
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Receptors, Mitogen / genetics*
  • Receptors, Mitogen / metabolism
  • Receptors, Somatomedin / antagonists & inhibitors
  • Signal Transduction / genetics
  • Thiazoles / administration & dosage*

Substances

  • Pyrimidines
  • Receptors, Mitogen
  • Receptors, Somatomedin
  • Thiazoles
  • Discoidin Domain Receptors
  • Proto-Oncogene Proteins c-ret
  • Receptor Protein-Tyrosine Kinases
  • Dasatinib