The ErbB2/ErbB3 heterodimer functions as an oncogenic unit: ErbB2 requires ErbB3 to drive breast tumor cell proliferation

ErbB2 is a receptor tyrosine kinase whose activity in normal cells depends on dimerization with another ligand-binding ErbB receptor. In contrast, amplification of c-erbB2 in tumors results in dramatic overexpression and constitutive activation of the receptor. Breast cancer cells overexpressing ErbB2 depend on its activity for proliferation, because treatment of these cells with ErbB2-specific antagonistic antibodies or kinase inhibitors blocks tumor cells in the G1 phase of the cell cycle. Intriguingly, loss of ErbB2 signaling is accompanied by a decrease in the phosphotyrosine content of ErbB3. On the basis of these results, it has been proposed that ErbB3 might be a partner for ErbB2 in promoting cellular…

• FM
  Friedrich Miescher Institute for Biomedical Research
• KB
  Krebsliga Beider Basel
• NI
  National Institutes of Health