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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over-expression of the c-erbB-2 oncogene occurs in a proportion of human adenocarcinomas and in breast carcinoma is associated with poorer prognosis. Sections of formalin-fixed, paraffin-embedded tumour tissue from 22 patients with mammary and extramammary Paget's disease have been stained immunohistochemically using a monoclonal antibody (NCL-CB11) raised against a synthetic peptide from the C-terminal end of the predicted sequence of the c-erbB-2 protein product. All 12 cases of mammary Paget's disease showed membrane staining of intra-epidermal cells, indicating c-erbB-2 over-expression. Sections of underlying ductal breast carcinoma were available in nine cases; all nine tumours were c-erbB-2 positive and in eight the in situ component was of comedo or solid type. There was membrane staining of tumour cells in four of the 10 cases of extramammary Paget's disease; staining intensity was generally weaker than that observed in the cases of mammary disease. The possible implications of these findings for the histogenesis of both mammary and extramammary Paget's disease are discussed.
Histopathology 1990 Sep
PMID:c-erbB-2 oncoprotein expression in mammary and extramammary Paget's disease: an immunohistochemical study. 217 76

The erbB2 oncogene encodes a 185-kilodalton transmembrane protein whose sequence is similar to the epidermal growth factor receptor (EGFR). A 30-kilodalton factor (gp30) secreted from MDA-MB-231 human breast cancer cells was shown to be a ligand for p185erbB2. An antibody to EGFR abolished the tyrosine phosphorylation induced by EGF and transforming growth factor-alpha (TGF-alpha) but only partially blocked that produced by gp30 in SK-BR-3 breast cancer cells. In two cell lines that overexpress erbB2 but do not expresss EGFR (MDA-MB-453 breast cancer cells and a Chinese hamster ovary cell line that had been transfected with erbB2), phosphorylation of p185erbB2 was induced only by gp30. The gp30 specifically inhibited the growth of cells that overexpressed p185erbB2. An antibody to EGFR had no effect on the inhibition of SK-BR-3 cell colony formation obtained with gp30. Thus, it appeared that gp30 interacted directly with the EGFR and erbB2. Direct binding of gp30 to p185erbB2 was confirmed by binding competition experiments, where gp30 was found to displace the p185erbB2 binding of a specific antibody to p185erbB2. The evidence described here suggests that gp30 is a ligand for p185erbB2.
Science 1990 Sep 28
PMID:Direct interaction of a ligand for the erbB2 oncogene product with the EGF receptor and p185erbB2. 221 96

Karyotypic analysis of tumor specimens from 29 patients with untreated epithelial ovarian carcinoma was performed at the University of Kentucky Medical Center. Twenty-three of the twenty-nine tumors had adequate cells for analysis. Seventeen of these tumors exhibited chromosome abnormalities. Chromosome alterations were complex, with an average of seven different abnormal chromosomal patterns per tumor (range 2-14). Chromosomes 1 and 11 were the most commonly involved, being abnormal in 89 and 83% of tumors, respectively. Chromosomes 3 and 7 were also frequently abnormal. In contrast to invasive tumors, alterations in chromosomes 1 and 11 were not seen in the two tumors of borderline malignant potential. Evidence for DNA amplification of IGF2, Ha-ras-1, and c-ets was not observed. Amplification of the c-erbB-2 oncogene was present in two tumors. These findings indicate that multiple karyotypic abnormalities occur in untreated epithelial ovarian malignancies, with chromosomes 1 and 11 being the most frequently abnormal. These data also suggest that alterations of these chromosomes may be associated with the biologically aggressive behavior of frankly invasive ovarian tumors.
Gynecol Oncol 1990 Sep
PMID:Chromosome abnormalities in human epithelial ovarian malignancies. 222 64

The etiology of breast cancer is thought to involve a complex interplay of various factors, among them: genetic alterations. Multiple studies have been made to identify and characterize mutations that frequently occur during tumorigenesis. In human breast cancer, some of these alterations involve implication of proto-oncogenes (c-myc, c-erbB-2 and int-2) that have been shown to contribute to tumorigenesis by using the transgenic mouse model. Loss of heterozygoty represents the other important type of abnormalities that has been frequently observed in breast tumor DNAs; these specific genic deletions could inactivate or remove suppressor genes. In some studies, specific alterations have been associated with some clinical parameters, but have led to numerous controversies. Larger studies would be necessary to confirm some alterations as useful prognostic factors of the post-surgical course of the disease.
Pathol Biol (Paris) 1990 Sep
PMID:[Cancer of the breast. Genetic alterations and prognostic factors]. 223 89

As a first step toward developing a structural map of key sites on the epidermal growth factor (EGF) receptor, we have used resonance energy transfer to measure the distance of closest approach between the receptor-bound growth factor molecule and lipid molecules at the surface of the plasma membrane. EGF, specifically labeled at its amino terminus with fluorescein 5-isothiocyanate, was used as an energy donor in these experiments, while either octadecylrhodamine B or octadecylrhodamine 101, inserted into plasma membranes isolated from human epidermoid carcinoma (A431) cells, served as the energy acceptors. The energy transfer measurements indicate that the amino terminus of the bound growth factor is about 67 A away from the plasma membrane. On the basis of the dimensions of the EGF molecule, this suggests that EGF binds to a site on its receptor that is a considerable distance (52-82 A) from the surface of these cells. Identical results were obtained under conditions where the receptor functions as an active tyrosine kinase, suggesting that the relative juxtaposition of the EGF binding domain to the membrane surface does not change with receptor autophosphorylation or with the activation of the receptor tyrosine kinase activity.
Biochemistry 1990 Sep 18
PMID:Location of the epidermal growth factor binding site on the EGF receptor. A resonance energy transfer study. 227 54

Levels of epidermal growth factor (EGF) receptor expression vary widely among cell lines derived clonally from a chemically transformed population of rat liver epithelial cells. Retinoic acid (RA), a derivative of vitamin A that stimulates differentiation in a number of embryonal cell lines, increases the level of 125I-EGF binding in several clones of the transformed cell lines. One such cell line, GP6ac, which reverts to a less transformed phenotype when treated with RA, exhibited a 3-4-fold increase in surface EGF receptors with prolonged (2-5-day) RA exposure. The increase persisted as long as the cells were treated with RA. The increase in surface EGF receptors was due to induction of receptor biosynthesis, which occurred within 4 h at both the mRNA and protein levels and persisted until the RA was withdrawn. Paradoxically, the RA response was accompanied by an initial 40-50% decrease in 125I-EGF binding during the first 12 h of RA treatment. The decrease was due primarily to a reduction of receptor affinity. Since the phorbol ester 12-O-tetradecanoylphorbol-13-acetate also decreases 125I-EGF binding and increases EGF receptor biosynthesis in GP6ac cells, we tested the effect of RA in cells depleted of protein kinase C by prolonged treatment (18 h) with 10 microM 12-O-tetradecanoylphorbol-13-acetate. The absence of protein kinase C did not affect the induction of receptor mRNA and protein or the decrease in binding during the early period of RA exposure. This indicates that RA induction of EGF receptor synthesis in GP6ac cells involves signaling pathways distinct from those utilized by phorbol esters.(ABSTRACT TRUNCATED AT 250 WORDS)
Cell Growth Differ 1990 Sep
PMID:Characterization of epidermal growth factor receptor induction by retinoic acid in a chemically transformed rat liver cell line. 228 80

Treatment of immature female Sprague-Dawley rats with 17 beta-estradiol (5 micrograms/animal) resulted in an increase in uterine epidermal growth factor (EGF) receptor binding activity. Moreover, in a separate study it was also shown that 17 beta-estradiol increased steady-state levels of rat uterine EGF receptor mRNA as determined by Northern analysis. In contrast, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) caused a dose-response decrease in constitutive rat uterine EGF receptor binding activity and this was paralleled by a decrease in steady-state levels of uterine EGF receptor mRNA. Cotreatment of the animals with both TCDD (16 nmol/kg) and 17 beta-estradiol (5 micrograms/rat) gave results which showed that TCDD significantly inhibited the estrogen-induced increases in rat uterine EGF receptor binding activity and EGF receptor mRNA levels. These results further extend the range of antiestrogenic properties of TCDD and suggest that the inhibition of growth factor expression may play a role in the growth-inhibiting properties of TCDD in estrogen-responsive tissues or cells.
Mol Cell Endocrinol 1990 Sep 10
PMID:2,3,7,8-Tetrachlorodibenzo-p-dioxin inhibition of 17 beta-estradiol-induced increases in rat uterine epidermal growth factor receptor binding activity and gene expression. 228 33

Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map the distribution on frozen skin sections of an extracellular epitope on the EGF receptor. The [125I]EGF binding experiments showed accessible, unoccupied EGF receptors to be present on the epidermal basal cells (with reduced binding to spinous cells), the basal cells of the hair shaft and sebaceous gland, the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing presumptive cortex cells, excluding the medulla, lying around and above the upper dermal papilla of anagen hair follicles, epithelial cells around the lower dermal papilla region, and in some tissue samples the cell margins of the viable differentiating layers of the epidermis. In a control study, to clarify whether EGF-R1 could recognize molecules unrelated to the EGF receptor, the EGF binding and EGF-R1 recognition profiles were compared on cultures of SVK14 cells, a SV40 transformed human keratinocyte cell line. EGF binding and EGF-R1 monoclonal antibody distribution on these cells was found to be similar, indicating that, at least for SVK14 cells, EGF-R1 binding provides a reliable marker for EGF binding. Explanations for the discrepancies between these two methods for determining EGF receptor distribution in human skin are discussed, including the possibility that latent EGF receptors, unable to bind [125I]EGF, may be present in some differentiating epithelial compartments.
J Invest Dermatol 1985 Sep
PMID:Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition. 241 22

An expression vector was constructed from part of pSV2neo with the 3'-ClaI fragment of the epidermal growth factor (EGF) receptor cDNA inserted in an inverted orientation downstream from the human metallothionein (MT) IIa promoter. The human squamous carcinoma cell line NA, which overproduces EGF receptor, was transfected with this vector and selected for resistance to the neomycin derivative G418. One of the stable transfectants had a 90% reduction in cell-surface EGF receptor in response to ZnSO4. The nascent EGF receptor peptide was also decreased with concurrent induction of MT mRNA. These data suggest that the antisense transcript regulated by the MT promoter inhibits the expression of the endogenous EGF receptor genes. Although no transcripts from the antisense gene were detected, the results indicate that transfection with the antisense vector provides a technique by which to modulate the number of EGF receptors on the cell surface of squamous cell carcinomas.
Exp Cell Res 1989 Sep
PMID:Reduction of EGF receptor levels in human tumor cells transfected with an antisense RNA expression vector. 247 67

Transforming growth factor-alpha (TGF-alpha) is a growth-promoting protein that binds to the epidermal growth factor (EGF) receptor. To identify critical residues that govern TGF-alpha-EGF receptor binding, we prepared site-specific substitution mutants of TGF-alpha. Mutant proteins were tested in receptor-binding and mitogenesis assays. Semiconservative substitutions at positions 4, 12, 18, and 45 decreased biological activity 2.1- to 14-fold. The conservative substitution of lysine for arginine at position 42 completely eliminated biological activity. Amino acid composition analysis of proteolytic fragments from TGF-alpha and the Lys-42 mutant indicated that these proteins contained the same disulfide bonds. These studies suggest that arginine 42 may be a contact point for TGF-alpha-EGF receptor interaction.
Mol Cell Biol 1989 Sep
PMID:Substitution of lysine for arginine at position 42 of human transforming growth factor-alpha eliminates biological activity without changing internal disulfide bonds. 250 41


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