Transcription-dependent epidermal growth factor receptor activation by hepatocyte growth factor

Mol Cancer Res. 2008 Jan;6(1):139-50. doi: 10.1158/1541-7786.MCR-07-0236.

Abstract

The mechanisms and biological implications of coordinated receptor tyrosine kinase coactivation remain poorly appreciated. Epidermal growth factor receptor (EGFR) and c-Met are frequently coexpressed in cancers, including those associated with hepatocyte growth factor (HGF) overexpression, such as malignant astrocytoma. In a previous analysis of the HGF-induced transcriptome, we found that two EGFR agonists, transforming growth factor-alpha and heparin-binding epidermal growth factor-like growth factor (HB-EGF), are prominently up-regulated by HGF in human glioma cells. We now report that stimulating human glioblastoma cells with recombinant HGF induces biologically relevant EGFR activation. EGFR phosphorylation at Tyr(845) and Tyr(1068) increased 6 to 24 h after cell stimulation with HGF and temporally coincided with the induction of transforming growth factor-alpha (~5-fold) and HB-EGF (~23-fold) expression. Tyr(845) and Tyr(1068) phosphorylation, in response to HGF, was inhibited by cycloheximide and actinomycin D, consistent with a requirement for DNA transcription and RNA translation. Specifically, blocking HB-EGF binding to EGFR with the antagonist CRM197 inhibited HGF-induced EGFR phosphorylation by 60% to 80% and inhibited HGF-induced S-G(2)-M transition. CRM197 also inhibited HGF-induced anchorage-dependent cell proliferation but had no effect on HGF-mediated cytoprotection. These findings establish that EGFR can be activated with functional consequences by HGF as a result of EGFR ligand expression. This transcription-dependent cross-talk between the HGF receptor c-Met and EGFR expands our understanding of receptor tyrosine kinase signaling networks and may have considerable consequences for oncogenic mechanisms and cancer therapeutics.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacterial Proteins / pharmacology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cytoprotection / drug effects
  • DNA Damage
  • Enzyme Activation / drug effects
  • ErbB Receptors / metabolism*
  • Gene Expression Regulation, Neoplastic / drug effects
  • Heparin-binding EGF-like Growth Factor
  • Hepatocyte Growth Factor / pharmacology*
  • Humans
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Ligands
  • Mitogen-Activated Protein Kinases / metabolism
  • Phosphorylation / drug effects
  • Phosphotyrosine / metabolism
  • Protein Biosynthesis / drug effects
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism
  • Transcription, Genetic / drug effects*
  • Transforming Growth Factor alpha / genetics
  • Transforming Growth Factor alpha / metabolism

Substances

  • Bacterial Proteins
  • HBEGF protein, human
  • Heparin-binding EGF-like Growth Factor
  • Intercellular Signaling Peptides and Proteins
  • Ligands
  • RNA, Messenger
  • RNA, Small Interfering
  • Transforming Growth Factor alpha
  • CRM197 (non-toxic variant of diphtheria toxin)
  • Phosphotyrosine
  • Hepatocyte Growth Factor
  • ErbB Receptors
  • Mitogen-Activated Protein Kinases