Type 1 receptor tyrosine kinases are differentially phosphorylated in mammary carcinoma and differentially associated with steroid receptors

Am J Pathol. 1996 Feb;148(2):549-58.

Abstract

The neu/erbB-2/HER-2 proto-oncogene is amplified and/or overexpressed in up to 30% of mammary carcinomas and has been variably correlated with poor prognosis. The signaling activity of the encoded receptor tyrosine kinase is regulated by interactions with other type 1 receptors and their ligands. We have used a novel approach, phosphorylation-sensitive anti-Neu antibodies, to quantify signaling by Neu and epidermal growth factor receptor in a panel of frozen sections of mammary carcinoma specimens. We also determined the relationship of Neu, phosphorylated Neu (and epidermal growth factor receptor), and phosphotyrosine to the expression of Neu-related receptors (epidermal growth factor receptor, HER-3, and HER-4) and to prognostic factors (estrogen and progesterone receptor). We found that tyrosine phosphorylation of Neu (and hence signaling activity) is highly variable among mammary carcinomas. Neu and HER-4 were associated with divergent correlates, suggesting that they have profoundly different biological activities. These results have implications for etiology of mammary carcinoma for clinical evaluation of mammary carcinoma patients, and for development of Neu-targeted therapeutic strategies.

Publication types

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

MeSH terms

  • Biomarkers, Tumor
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • ErbB Receptors / metabolism*
  • Female
  • Frozen Sections
  • Genes, erbB-2
  • Humans
  • Immunohistochemistry
  • Phosphorylation
  • Phosphotyrosine / metabolism
  • Prognosis
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Receptor, ErbB-2 / metabolism*
  • Receptor, ErbB-4
  • Receptors, Estrogen / metabolism
  • Receptors, Progesterone / metabolism
  • Receptors, Steroid / metabolism*
  • Retrospective Studies

Substances

  • Biomarkers, Tumor
  • Receptors, Estrogen
  • Receptors, Progesterone
  • Receptors, Steroid
  • Phosphotyrosine
  • ERBB4 protein, human
  • ErbB Receptors
  • Receptor Protein-Tyrosine Kinases
  • Receptor, ErbB-2
  • Receptor, ErbB-4