ErbB-2 becomes rapidly phosphorylated and activated following treatment of many cell lines with epidermal growth factor (EGF) or Neu differentiation factor (NDF). However, these factors do not directly bind ErbB-2, and its activation is likely to be mediated via transmodulation by other members of the type I/EGF receptor (EGFR)-related family of receptor tyrosine kinases. The precise role of Er...

The erbB-2 proto-oncogene belongs to a receptor tyrosine kinase family that includes the epidermal growth factor receptor, erbB-2, erbB-3, and erbB-4. erbB-2 is expressed in basal cells of the squamous epithelia and the outer root sheath of the hair follicles, but its function in epidermal development has not been well studied. To investigate its role in the skin, we created transgenic mice har...

Deregulation of the ErbB (proto-oncogene B of the avian erythroblastosis virus AEV-H strain) receptor network is well recognized as an oncogenic driver in epithelial cancers. Several targeted drugs have been developed, including antibodies and small-molecule kinase inhibitors, each of them characterized by distinct patterns of ErbB receptor interactions. Understanding the precise pharmacologica...

The relationship between c-erbB-2 gene expression (assessed immunohistochemically), S-phase fraction (SPF) and prognosis has been analysed in 172 women with primary breast cancer. c-erbB-2 staining was independent of age, tumour size, number of nodes involved, tumour grade and DNA ploidy, but was more common in oestrogen receptor (ER) negative tumours (P = 0.02) and progesterone receptor (PgR) ...

Signal transduction mediated by ErbB/HER receptor tyrosine kinases is crucial for the development and maintenance of epithelial tissues, and aberrant signaling is frequently associated with malignancies of epithelial origin. This review focuses on the roles played by the Hsp90 chaperone machinery in the regulation of signaling through the ErbB/HER network, and discusses potential therapeutic st...

Recent clinical data (1) suggest that c-erbB-2 overexpression/amplification might be associated with tamoxifen resistance in patients with estrogen receptor (ER)-positive tumors. This association is controversial, however, and the question of the efficacy of hormone therapy in these patients is still a matter of debate. In a recent issue of the Journal, Konecny et al. (2) provided some answers ...

The aim of this study was to evaluate c-erbB-2 overexpression by means of a quantitative biochemical technique in 488 primary breast cancer patients with long-term follow-up (median, 10 years) and its relation to other biochemical prognostic factors (uPA, p53, and epidermal growth factor receptor) and adjuvant therapy. High levels of c-erbB-2 (>500 IU/mg protein) were associated with estrogen r...

Epidermal growth factor receptor (EGFR), ErbB-2, and ErbB-4 are members of the type 1 receptor tyrosine kinase family. Overexpression of these receptors, especially ErbB-2 and EGFR, has been implicated in multiple forms of cancer. Inhibitors of EGFR tyrosine kinase activity are being evaluated clinically for cancer therapy. The potency and selectivity of these inhibitors may affect the efficacy...

The c-erbB-2 gene is a v-erbB-related proto-oncogene which is distinct from the gene encoding the epidermal growth factor receptor. By using two independent methods, hybridization of both sorted chromosomes and metaphase spreads with cloned c-erbB-2 DNA, we mapped the c-erbB-2 locus on human chromosome 17 at q21, a specific breakpoint observed in a translocation associated with acute promyelocy...

ErbB-2/HER2 is an oncogenic tyrosine kinase that regulates a signalling network by forming ligand-induced heterodimers with several growth factor receptors of the ErbB family. Hsp90 and co-chaperones regulate degradation of ErbB-2 but not other ErbB members. Here, we report that the role of Hsp90 in modulating the ErbB network extends beyond regulation of protein stability. The capacity of ErbB...