Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immunohistochemical detection of the c-erbB-2 oncopeptide (p185erbB2) has been shown to be a valid marker for over-expression of this oncogene. To evaluate the possible relevance of gene expression to the proliferation of hepatocytes and bile ducts in human disease, the authors applied a monoclonal anti-p185 antibody to formalin-fixed, paraffin-embedded tissues from 67 examples of benign proliferative and neoplastic hepatic lesions and fetal liver. Focal membrane-based reactivity for the oncopeptide was detected on tumor cells in two of eight hepatocellular carcinomas and on tumor cells and adjacent bile ducts and hepatocytes in four of six cholangiocarcinomas. Each of the latter four lesions were in patients with primary sclerosing cholangitis. No reactivity was obtained in examples of hepatoblastoma, mixed cholangiocarcinoma-hepatocellular carcinoma, bile duct adenoma, or hepatocellular adenoma. Weak staining for p185erbB2 also was seen in two of seven cases of (sub)massive hepatic necrosis and two examples of postnecrotic cirrhosis, all of which were secondary to either hepatitis B or C virus infection. No other benign proliferative lesions were labeled by the anti-p185 antibody, including cases of chronic allograft rejection, necrosis secondary to hepatic artery thrombosis, metabolic-associated and nonmetabolic-associated cirrhosis, focal nodular hyperplasia, and nodular regenerative hyperplasia. The authors' results indicate that c-erbB-2 may be amplified in specific neoplastic and hepatitis B virus and hepatitis C virus infectious lesions of liver. The authors postulate that: (1) c-erbB-2 immunoreactivity may be a marker for malignant transformation in primary sclerosing cholangitis; and 2) overproduction of p185erbB2 may be an epiphenomenon of hepatitis B virus or hepatitis C virus infection.
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PMID:Immunoreactivity for c-erbB-2 oncopeptide in benign and malignant diseases of the liver. 137 19

The E3 region of adenovirus induces down-regulation of epidermal growth factor receptor (EGFR) through endocytosis. Here we report that an EGFR-related protein, the HER-2/c-erbB-2 gene product, p185, is also down-regulated by adenovirus, but via a different mechanism. We found that the adenovirus E1a gene is responsible for the repression of HER-2/c-erbB-2 at the RNA level.
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PMID:Repressed expression of the HER-2/c-erbB-2 proto-oncogene by the adenovirus E1a gene products. 167 40

c-erbB-2 and ras expression was measured on tumor extracts from 132 human primary breast carcinomas, by immunoblotting analysis. Expression of the c-erbB-2-encoded p185 protein was observed in 39% of the samples and found to correlate with c-erbB-2 gene amplification, detected by Southern analysis in 19 of the 77 available tumor DNAs. p185 expression was linked to the absence of progesterone receptors, but it was not related to lymph-node status or to other clinico-pathological parameters. Levels of the ras-encoded p21 proteins higher than in normal breast tissues were found in 71% of the samples. No significant correlation was seen between p21 level and the available clinical parameters. Conversely, there was a strong positive correlation between p21 and p185 levels. Analysis of follow-up data revealed that p185 expression was associated with a shorter time to relapse and death. Most notably, the contemporaneous expression of p185 and of high p21 levels was more effective than p185 expression alone in identifying cases with poor prognosis. The prognostic value of p185/p21 co-expression was particularly significant in progesterone-receptor-positive tumors. Our data suggest that c-erbB-2 and ras may act synergistically to endow breast-tumor cells with a highly aggressive phenotype.
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PMID:c-erbB-2 and ras expression levels in breast cancer are correlated and show a co-operative association with unfavorable clinical outcome. 167 66

P185 is a receptor-like protein encoded by the neu/erbB-2 proto-oncogene. A point mutation in the transmembrane domain renders this protein oncogenic. We report here that incubation of cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulates the phosphorylation of the normal neu protein (p185) and the oncogenic neu protein (p185*). The increased phosphorylation occurs mainly on serine and threonine residues. Phosphate labeling experiments showed that TPA causes a reduction of basal phosphotyrosine in p185 but not p185*. Immunoblotting with antiphosphotyrosine antibody yielded similar results. TPA also inhibited tyrosine phosphorylation of p185* in an in vitro immune complex kinase assay. These data suggest that protein kinase C, the receptor for TPA, regulates p185 function through serine or threonine phosphorylation.
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PMID:TPA inhibits the tyrosine kinase activity of the neu protein in vivo and in vitro. 167 82

Lobular carcinoma in situ (LCIS) has uncertain malignant potential; biologic markers that will identify patients at risk for a poor clinical outcome have been sought actively. Amplification of the c-erbB-2 protooncogene has been correlated with poor prognosis in invasive mammary carcinoma, and immunohistochemical evaluation for expression of the oncogene protein has been correlated with gene amplification. The authors retrospectively evaluated 62 cases of lobular neoplasia for expression of the c-erbB-2 gene product on formalin-fixed, deparaffinized sections, using two monoclonal anti-erbB-2 (p185) antibodies (c-neu Ab3 and m-erb) and one polyclonal anti-erbB-2 antibody (pAb 1) by the avidin-biotin-peroxidase method. All 62 cases were negative with the pAb 1 antibody; one of 62 cases was weakly positive with the c-neu Ab3 in a membranous pattern. Expression of c-erbB-2 gene product was identified on adjacent invasive ductal carcinoma in one case and in adjacent ductal carcinoma in situ in another. None of 15 cases if infiltrating lobular carcinoma was positive with either of the two anti-c-erbB-2 antibodies. Strong positivity was found on benign epithelium in one case, demonstrating epitheliosis. In summary, evidence of expression of the c-erbB-2 gene product was found in one of 57 cases of LCIS and none of 15 cases of invasive lobular carcinoma. This suggests that, in contrast to reported data concerning intraductal and invasive ductal carcinoma, c-erbB-2 oncogene amplification and/or overexpression does not play a significant role in the progression of lobular breast neoplasia.
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PMID:C-erbB-2 oncogene protein in in situ and invasive lobular breast neoplasia. 167 30

Overexpression of the p185 product of the c-erb B2/neu gene is correlated with cell transformation and tumorigenesis. To study expression of this gene, a 1548-base pair fragment (-1571 to -24 bp relative to the ATG initiator codon) of the human c-erb B2/neu 5'-noncoding region was isolated, sequenced, and analyzed with respect to basal and inducible activity using the luciferase expression vector pSVOAL delta 5'. This fragment contained an Alu repetitive element which was confirmed in two independent clones. Basal activity of the 1548-base pair fragment was equivalent to the epidermal growth factor receptor promoter region and 32 and 16% as active as the Herpes simplex thymidine kinase and Rous sarcoma virus promoters, respectively. Induction of luciferase activity was observed in response to epidermal growth factor, 12-O-tetradecanoylphorbol-13-acetate, dibutyryl cAMP, and retinoic acid. Additive and synergistic responses with more than 30-fold increases were observed after treatment with combinations of inducing agents, indicating complex regulation of this gene. These results show that the promoter region of the c-erb B2/neu gene contains sequences that dictate regulatory responses to several environmental signals.
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PMID:Structure and inducible regulation of the human c-erb B2/neu promoter. 196 58

The use of antibodies permits the study of oncogene product expression in cells and tissues. However, quantitation of the levels of expression in immunohistochemical preparations is beset by difficulties, and the available scoring system provide semiquantitative data at best. Here we describe the use of computer-assisted image analysis for determination of oncoprotein levels in a model system and compare the results with those generated by flow cytometric analysis. The oncogene products measured are located in the nucleus (c-myc p62 and c-fos p55), the inner surface of the membrane (c-ras p21), and both sides of the membrane (c-erbB-2 p185). In each instance, both analytic modalities yielded concordant results. Our data indicate that computer-assisted image analysis is a useful tool for quantitating cell components in immunohistochemical preparations.
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PMID:Quantitation of oncogene products by computer-assisted image analysis and flow cytometry. 196 31

The c-erbB-2 oncogene is thought to play a relevant role in the development and progression of mammary neoplasia. Using the human breast cancer cell lines T47D and MCF7, we found that the arrest of cell growth induced by a steroid-depleted medium was accompanied by a strong increase of c-erbB-2 mRNA and of the c-erbB-2-encoded p185 protein. The treatment of arrested cells with estrogens was found to resume cell proliferation and to inhibit dramatically c-erbB-2 expression at both mRNA and protein level. The regulation of c-erbB-2 expression was remarkably different from that observed for c-myc, which was strongly stimulated by estrogens, and ras, whose expression was unaffected all through the treatments. In addition, in the normal rat mammary gland undergoing development and differentiation during pregnancy and lactation, p185 expression was detected only in the functionally differentiated tissue. Altogether, our data indicate that the expression of c-erbB-2 is repressed during estrogen-induced proliferation and enhanced during growth arrest and/or differentiation of mammary cells.
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PMID:Inhibition of c-erbB-2 oncogene expression by estrogens in human breast cancer cells. 197 27

The protein product of the neu protooncogene, p185, is a tyrosine kinase with a high degree of sequence homology to the epidermal growth factor (EGF) receptor. Although p185 does not bind EGF, EGF stimulates tyrosine phosphorylation of p185. To determine the mechanism of this interaction we have used a vaccinia virus/bacteriophage T7-based transient gene expression system to induce production of normal and kinase-deficient forms of p185 in the absence and presence of EGF receptors. Tyrosine phosphorylation of kinase-deficient p185 was observed, but only in the presence of the EGF receptor. These findings strongly support the hypothesis that p185 is a substrate for the EGF receptor tyrosine kinase in a tyrosine kinase cascade.
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PMID:The epidermal growth factor receptor and the product of the neu protooncogene are members of a receptor tyrosine phosphorylation cascade. 197 18

The Mr 185,000 glycoprotein encoded by human c-erbB-2/neu/HER2 gene, termed c-erbB-2 gene product, shows a close structural similarity with epidermal growth factor receptor and is now regarded to be a growth factor receptor for an as yet unidentified ligand. Abundant c-erbB-2 mRNA was demonstrated by Northern blot studies in the human breast cancer cell line SK-BR-3. Cellular radiolabeling experiments followed by immunoprecipitation with three different anti-c-erbB-2 gene product antibodies, recognizing extracellular domain, kinase domain, and carboxyl-terminal portion, respectively, demonstrated the production of a large amount of c-erbB-2 gene product which had the capacity to be phosphorylated. Immunization of mice with concentrated culture medium conditioned by SK-BR-3 cells always generated antibodies against c-erbB-2 gene product, demonstrating that this culture medium contained substance(s) immunologically indistinguishable from c-erbB-2 gene product. This observation was supported by the successful development of a monoclonal antibody against c-erbB-2 gene product, GFD-OA-p185-1, by immunizing mice with this culture medium. The biochemical nature of the substance(s) present in the culture medium was further characterized. When the culture medium conditioned by [35S]cysteine-labeled SK-BR-3 cells was immunoprecipitated by three different anti-c-erbB-2 gene product antibodies, only the antibody recognizing extracellular domain precipitated the [35S]-labeled protein with a molecular weight of 110,000, namely p110. The newly developed monoclonal antibody also immunoprecipitated this protein.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The presence of c-erbB-2 gene product-related protein in culture medium conditioned by breast cancer cell line SK-BR-3. 198 Nov 43


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