GPCR-induced migration of breast carcinoma cells depends on both EGFR signal transactivation and EGFR-independent pathways

Biol Chem. 2005 Sep;386(9):845-55. doi: 10.1515/BC.2005.099.

Abstract

The epidermal growth factor receptor (EGFR) plays a key role in the regulation of important cellular processes under normal and pathophysiological conditions such as cancer. In human mammary carcinomas the EGFR is involved in regulating cell growth, survival, migration and metastasis and its activation correlates with the lack of response in hormone therapy. Here, we demonstrate in oestrogen receptor-positive and -negative human breast cancer cells and primary mammary epithelial cells a cross-communication between G protein-coupled receptors (GPCRs) and the EGFR. We present evidence that specific inhibition of ADAM15 or TACE blocks GPCR-induced and proHB-EGF-mediated EGFR tyrosine phosphorylation, downstream mitogenic signalling and cell migration. Notably, activation of the PI3K downstream mediator PKB/Akt by GPCR ligands involves the activity of sphingosine kinase (SPHK) and is independent of EGFR signal transactivation. We conclude that GPCR-induced chemotaxis of breast cancer cells is mediated by EGFR-dependent and -independent signalling pathways, with both parallel pathways having to act in concert to achieve a complete migratory response.

MeSH terms

  • ADAM Proteins / antagonists & inhibitors
  • ADAM Proteins / genetics
  • ADAM Proteins / metabolism
  • ADAM17 Protein
  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Sequence
  • Animals
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Movement / physiology*
  • Enzyme Activation
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism
  • ErbB Receptors / physiology*
  • Female
  • Humans
  • Membrane Proteins / antagonists & inhibitors
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Metalloproteases / antagonists & inhibitors
  • Metalloproteases / metabolism
  • Mice
  • Mitogen-Activated Protein Kinases / metabolism
  • Molecular Sequence Data
  • Phospholipids / pharmacology
  • Phosphorylation
  • Pregnancy
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptor Cross-Talk / physiology
  • Receptors, G-Protein-Coupled / agonists
  • Receptors, G-Protein-Coupled / metabolism
  • Receptors, G-Protein-Coupled / physiology*
  • Shc Signaling Adaptor Proteins
  • Signal Transduction / physiology
  • Src Homology 2 Domain-Containing, Transforming Protein 1
  • Transfection
  • Tumor Cells, Cultured

Substances

  • Adaptor Proteins, Signal Transducing
  • Membrane Proteins
  • Phospholipids
  • Receptors, G-Protein-Coupled
  • SHC1 protein, human
  • Shc Signaling Adaptor Proteins
  • Shc1 protein, mouse
  • Src Homology 2 Domain-Containing, Transforming Protein 1
  • ErbB Receptors
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinases
  • Metalloproteases
  • ADAM Proteins
  • ADAM15 protein, human
  • ADAM17 Protein
  • ADAM17 protein, human
  • Adam17 protein, mouse