Simultaneous suppression of Erk and Akt/PKB activation by a Gab1 pleckstrin homology (PH) domain decoy

Anticancer Res. 2003 Jul-Aug;23(4):3231-6.

Abstract

Background: Gab1 is a pleckstrin homology (PH) domain containing docking protein that mediates EGF-induced Erk and Akt/PKB activation. Using a decoy strategy, we explored the Gab1 PH domain as a potential target for simultaneous inhibition of Erk and Akt/PKB activation.

Materials and methods: MDA-MB-468 and SK-BR-3 derived cell lines were established for doxycycline-inducible expression of a Gab1 PH domain decoy. Erk and Akt activation, matrix metalloprotease-9 (MMP-9) secretion and cell motility were analyzed.

Results: Expression of the Gab1 PH domain decoy in these cells suppressed EGF-induced Erk2 and Akt/PKB activation, MMP-9 secretion and cell migration. The constitutively active Akt/PKB in the PTEN-negative MDA-MB-468 cells was also suppressed by the Gab1 PH domain decoy.

Conclusion: These results illustrate that the Gab1 PH domain is a potential target for antagonizing ErbB activation and PTEN inactivation, and for suppression of ErbB-induced metastatic activities in breast cancer cells.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Breast Neoplasms / enzymology*
  • Breast Neoplasms / genetics
  • COS Cells
  • Chlorocebus aethiops
  • Enzyme Activation / physiology
  • Epidermal Growth Factor / antagonists & inhibitors
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / antagonists & inhibitors*
  • ErbB Receptors / physiology
  • Humans
  • Matrix Metalloproteinase 9 / biosynthesis
  • Matrix Metalloproteinase Inhibitors
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors*
  • Mitogen-Activated Protein Kinases / metabolism
  • PTEN Phosphohydrolase
  • Phosphoproteins / genetics
  • Phosphoproteins / physiology*
  • Phosphoric Monoester Hydrolases / antagonists & inhibitors*
  • Phosphoric Monoester Hydrolases / physiology
  • Protein Serine-Threonine Kinases*
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / antagonists & inhibitors*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Signal Transduction / physiology
  • Transfection
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins / antagonists & inhibitors*
  • Tumor Suppressor Proteins / physiology

Substances

  • Adaptor Proteins, Signal Transducing
  • GAB1 protein, human
  • Matrix Metalloproteinase Inhibitors
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • Tumor Suppressor Proteins
  • Epidermal Growth Factor
  • ErbB Receptors
  • AKT1 protein, human
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinases
  • Phosphoric Monoester Hydrolases
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • Matrix Metalloproteinase 9