Activation (tyrosine phosphorylation) of ErbB-2 (HER-2/neu): a study of incidence and correlation with outcome in breast cancer.

PURPOSE We hypothesize that phosphorylated ErbB-2 (P-ErbB-2, identified by a novel antibody PN2A) may provide either more significant or additional prognostic marker data for breast cancer patients. This study was designed to compare the incidence and prognostic value of ErbB-2 (HER-2/neu) and P-ErbB-2 immunoexpression in archival breast cancer samples. MATERIALS AND METHODS Eight hundred sixteen invasive breast cancers with a median of 16.3 years of follow-up were immunostained for ErbB-2 (using antibody CB11) and P-ErbB-2 (using antibody PN2A). ErbB-2 and P-ErbB-2 data were compared with clinical, histologic, immunohistochemical, and outcome variables. RESULTS Of 816 primary breast cancers, 307 (38%) were positive for ErbB-2 and 37 (12% of ErbB-2 positive and 5% of the study population) expressed P-ErbB-2. P-ErbB-2 was not detected in ErbB-2-negative cases (n = 509). ErbB-2 immunohistochemical data were bimodal; patients with > or = 80% cellular expression had the shortest disease-free and disease-specific survival. P-ErbB-2 was associated with a higher percentage of ErbB-2-positive cells, a higher number of positive lymph nodes, and cellular proliferation. ErbB-2 and P-ErbB-2 were indicators of poor prognosis in node-positive patients in both univariate and multivariate analyses. We found that either P-ErbB-2 expression or high (> or = 80%) ErbB-2 expression provided the most significant prognostic value in node-positive cases by multivariate analyses. There were too few P-ErbB-2-positive cases and events in the node-negative patient group to allow statistical analysis of P-ErbB-2 in that subgroup. CONCLUSION PN2A immunostaining identified a subset (approximately 12% of ErbB-2-positive breast cancers) with activation (phosphorylation) of the receptor ErbB-2. P-ErbB-2 expression was strongly associated with higher levels of ErbB-2 expression (> or = 80%), although it was not a surrogate. Identification of cases with a high percentage of invasive breast cancer cells expressing ErbB-2 or determination of receptor activation via P-ErbB-2 may provide additional prognostic value in node-positive breast cancers.

[1]  W. Muller,et al.  Novel activating mutations in the neu proto-oncogene involved in induction of mammary tumors. , 1994, Molecular and cellular biology.

[2]  I. Ellis,et al.  Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up. , 2002, Histopathology.

[3]  L. Cantley,et al.  The erbB3 gene product is a receptor for heregulin. , 1994, The Journal of biological chemistry.

[4]  D A Berry,et al.  Dose and dose intensity as determinants of outcome in the adjuvant treatment of breast cancer. The Cancer and Leukemia Group B. , 1998, Journal of the National Cancer Institute.

[5]  J. Adelman,et al.  The HER-2/neu receptor tyrosine kinase gene encodes a secreted autoinhibitor. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[6]  S. Edge,et al.  Prognostic factors in breast cancer , 2005 .

[7]  C R King,et al.  erbB-2 is a potent oncogene when overexpressed in NIH/3T3 cells. , 1987, Science.

[8]  D A Berry,et al.  erbB-2, p53, and efficacy of adjuvant therapy in lymph node-positive breast cancer. , 1998, Journal of the National Cancer Institute.

[9]  D. Stern,et al.  EGF‐stimulated tyrosine phosphorylation of p185neu: a potential model for receptor interactions. , 1988, The EMBO journal.

[10]  T. van Raaij,et al.  The cellular response to neuregulins is governed by complex interactions of the erbB receptor family , 1995, Molecular and cellular biology.

[11]  F. Koerner,et al.  pS2 protein and steroid hormone receptors in invasive breast carcinomas , 1992, International journal of cancer.

[12]  Cori Bargmann,et al.  Oncogenic activation of the neu‐encoded receptor protein by point mutation and deletion. , 1988, The EMBO journal.

[13]  R. Cardiff,et al.  Elevated expression of activated forms of Neu/ErbB‐2 and ErbB‐3 are involved in the induction of mammary tumors in transgenic mice: implications for human breast cancer , 1999, The EMBO journal.

[14]  Julian Downward,et al.  Epidermal growth factor regulates p21 ras through the formation of a complex of receptor, Grb2 adapter protein, and Sos nucleotide exchange factor , 1993, Cell.

[15]  A. Thor,et al.  Comparison of mitotic index, in vitro bromodeoxyuridine labeling, and MIB-1 assays to quantitate proliferation in breast cancer. , 1999, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[16]  Michael Karin,et al.  Membrane targeting of the nucleotide exchange factor Sos is sufficient for activating the Ras signaling pathway , 1994, Cell.

[17]  J. Pierce,et al.  The role of autophosphorylation in modulation of erbB-2 transforming function. , 1990, The New biologist.

[18]  D. Weiner,et al.  A point mutation in the neu oncogene mimics ligand induction of receptor aggregation , 1989, Nature.

[19]  D. Berry,et al.  c-erbB-2 expression and response to adjuvant therapy in women with node-positive early breast cancer. , 1994, The New England journal of medicine.

[20]  D. Stern,et al.  Antiserum raised against a synthetic phosphotyrosine-containing peptide selectively recognizes p185neu/erbB-2 and the epidermal growth factor receptor. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[21]  Y. Yarden,et al.  Diversification of Neu differentiation factor and epidermal growth factor signaling by combinatorial receptor interactions. , 1996, The EMBO journal.

[22]  T. Akiyama,et al.  The transforming potential of the c-erbB-2 protein is regulated by its autophosphorylation at the carboxyl-terminal domain , 1991, Molecular and cellular biology.

[23]  G. Plowman,et al.  Heregulin induces tyrosine phosphorylation of HER4/p180erbB4 , 1993, Nature.

[24]  M. Hung,et al.  A novel splice variant of HER2 with increased transformation activity , 1998, Molecular carcinogenesis.

[25]  M. Kraus,et al.  Oncogenic potential of erbB-2 in human mammary epithelial cells. , 1991, Oncogene.

[26]  B. Lloveras,et al.  Evaluation of in vitro bromodeoxyuridine labeling of breast carcinomas with the use of a commercial kit. , 1991, American journal of clinical pathology.

[27]  Y. Yarden,et al.  A single autophosphorylation site confers oncogenicity to the Neu/ErbB‐2 receptor and enables coupling to the MAP kinase pathway. , 1994, The EMBO journal.

[28]  R. Weinberg,et al.  Molecular cloning of the neu gene: absence of gross structural alteration in oncogenic alleles. , 1986, Proceedings of the National Academy of Sciences of the United States of America.

[29]  T. Pawson,et al.  SH2 domains recognize specific phosphopeptide sequences , 1993, Cell.

[30]  Cori Bargmann,et al.  Multiple independent activations of the neu oncogene by a point mutation altering the transmembrane domain of p185 , 1986, Cell.

[31]  D. Stern,et al.  Oncogenic activation of p185neu stimulates tyrosine phosphorylation in vivo , 1988, Molecular and cellular biology.

[32]  D. Stern,et al.  The epidermal growth factor receptor and the product of the neu protooncogene are members of a receptor tyrosine phosphorylation cascade. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[33]  Y. Yarden,et al.  A hierarchical network of interreceptor interactions determines signal transduction by Neu differentiation factor/neuregulin and epidermal growth factor , 1996, Molecular and cellular biology.

[34]  D. Stern,et al.  Activation state-specific monoclonal antibody detects tyrosine phosphorylated p185neu/erbB-2 in a subset of human breast tumors overexpressing this receptor. , 1995, Cancer research.

[35]  V. Brown,et al.  Carboxyl-terminal deletion and point mutations decrease the transforming potential of the activated rat neu oncogene product. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[36]  J. Doherty,et al.  NH2-terminally truncated HER-2/neu protein: relationship with shedding of the extracellular domain and with prognostic factors in breast cancer. , 1998, Cancer research.

[37]  P. D’Eustachio,et al.  The SH2 domain protein GRB‐7 is co‐amplified, overexpressed and in a tight complex with HER2 in breast cancer. , 1994, The EMBO journal.

[38]  L. Norton,et al.  Dose and dose intensity of adjuvant chemotherapy for stage II, node-positive breast carcinoma. , 1994, The New England journal of medicine.

[39]  M. Klagsbrun,et al.  The Epidermal Growth Factor Receptor Couples Transforming Growth Factor-α, Heparin-binding Epidermal Growth Factor-like Factor, and Amphiregulin to Neu, ErbB-3, and ErbB-4* , 1996, The Journal of Biological Chemistry.

[40]  D. Stern,et al.  Functional assay for HER-2/neu demonstrates active signalling in a minority of HER-2/neu-overexpressing invasive human breast tumours. , 1996, British Journal of Cancer.

[41]  A. Ullrich,et al.  Increased expression of the putative growth factor receptor p185HER2 causes transformation and tumorigenesis of NIH 3T3 cells. , 1987, Proceedings of the National Academy of Sciences of the United States of America.

[42]  T. van Raaij,et al.  Betacellulin activates the epidermal growth factor receptor and erbB-4, and induces cellular response patterns distinct from those stimulated by epidermal growth factor or neuregulin-beta. , 1996, Oncogene.

[43]  L. Sobin,et al.  Histological Typing of Breast Tumors 1 , 1982 .

[44]  D. Cox.  Regression Models and Life-Tables , 1972 .

[45]  M. Luther,et al.  Involvement of pp60c-src with two major signaling pathways in human breast cancer. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[46]  E. Kawasaki,et al.  Accumulation of p53 tumor suppressor gene protein: an independent marker of prognosis in breast cancers. , 1992, Journal of the National Cancer Institute.