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)

We and others have previously reported that transforming growth factor-alpha (TGF alpha) expression is hormonally responsive and its expression is coregulated with that of its receptor [the epidermal growth factor (EGF) receptor]. The 5'-flanking region of the TGF alpha gene was characterized to determine whether it could confer hormone responsiveness to a reporter gene (luciferase) in human mammary carcinoma cells (MDA468). This segment of the gene is GC rich and contains an element strikingly similar to the core element of the EGF receptor gene that has been shown to mediate both basal and hormone-stimulated expression of the EGF receptor. We now report that a 313-basepair (bp) proximal element of the TGF alpha 5'-flanking region (-373 to -59 relative to the TGF alpha translation start codon) is capable of conferring responses to phorbol ester and EGF. This gene segment does not contain the EGF receptor gene homolog or potential AP-2-binding sites, suggesting that these elements are not necessary for basal and EGF- or phorbol ester-responsive TGF alpha gene expression. This 313-bp proximal element also confers proper transcriptional initiation to the chimeric TGF alpha-luciferase reporter construct, indicating it is the TGF alpha promoter. A 1.1-kilobase segment of the TGF alpha 5'-flanking region also confers retinoic acid, thyroid hormone, and glucocorticoid responsiveness despite the absence of recognizable steroid hormone receptor-binding sites. These hormones stimulate reporter expression 1.5- to 2-fold in a dose-dependent manner. Extension of the 5'-flanking region to -3500 results in marked suppression of reporter gene expression. These results indicate that the TGF alpha gene 5'-flanking sequence contains the elements responsible for hormonal responsiveness of this gene and that these elements are distinct from those that regulate the expression of the EGF receptor gene.
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PMID:Transcriptional regulation of the human transforming growth factor-alpha gene. 192 84

The nuclear DNA ploidy pattern and c-erbB-2 oncoprotein expression in primary and metastatic lesions were investigated using paraffin-embedded materials from 44 cases of colorectal carcinoma with hepatic metastases and 45 cases without hepatic metastases. The frequency of aneuploidy and positive staining of c-erbB-2 in primary tumor with hepatic metastases were significantly higher compared with those without hepatic metastases (p less than 0.05). There were significant correlations between diameter of metastases and DNA ploidy pattern of the metastases and between metachronous metastases, degree of metastases, vessel involvement and DNA ploidy pattern of the primary tumor. Positive staining of c-erbB-2 was detected more frequently with the advancement of depth of tumor invasion. There was no significant correlation between DNA ploidy pattern and c-erbB-2 expression. In the survival of patients whose primary tumor and hepatic metastases were resected, it was shown that DNA ploidy pattern of metastases was the most important independent prognostic factor. Expression of c-erbB-2 in primary tumor predicted the hepatic metastases.
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PMID:[DNA content and c-erbB-2 oncoprotein expression in hepatic metastases from colorectal carcinoma--in relation to clinicopathologic findings and prognosis]. 196 Nov 85

DNA from 24 ovarian tumors, including 16 carcinomas, was examined for amplification of the proto-oncogenes c-myc, int-2, and rc-erbB-2. All cases of carcinoma were also examined by flow cytometry for DNA ploidy and cell cycle analysis, and eight cases of carcinoma were examined for estrogen and progesterone receptors. Protooncogene amplification was not detected in the DNA of benign ovarian neoplasms, or of ovarian carcinomas with low malignant potential. Amplification of c-myc was detected in six of 12 cases of invasive carcinoma, int-2 amplification was present in one case, and c-erbB-2 amplification was not detected in any case. Among the seven cases evidencing protooncogene amplification, three cases showed aneuploidy in tumor DNA, while four showed diploidy. Two cases which showed aneuploidy in tumor DNA did not demonstrate any degree of protooncogene amplification. Protooncogene amplification was frequently associated with morphologic nuclear anaplasia and high mitotic count. Six of the seven cases demonstrating c-myc or int-2 were of the serous type or showed some degree of serous differentiation, while none of the four cases of purely mucinous carcinoma had evidence of amplification. While the total number of cases in the study was limited, it would appear from the trend demonstrated by the data that protooncogene amplification (particularly c-myc) may be involved in the pathogenesis of aggressive common epithelial tumors of the ovary.
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PMID:Protooncogene amplification and tumor ploidy in human ovarian neoplasms. 196 81

An immunohistochemical study of c-erbB-2 expression was carried out on in situ (non-invasive) breast carcinoma, using antibody 21N, raised to the intracytoplasmic domain of the c-erbB-2 oncogene product. Strong membrane staining was observed in 44 out of 74 (59 per cent) cases of ductal carcinoma in situ (DCIS), but none of 48 lobular carcinoma in situ (LCIS) lesions. A detailed comparative morphological evaluation using several different parameters, including histological subtypes, was performed within the DCIS group. The results showed that there was a significant correlation between c-erbB-2 expression and the presence of large cell size, periductal lymphoid cell infiltration, marked nuclear pleomorphism, multinucleation, and a high mitotic rate. Of these, cell size appears to be the most important predictor of c-erbB-2 status, followed by the presence of periductal lymphoid cell infiltration. These results indicate, firstly, that LCIS and DCIS are biologically (as well as histologically) different and, secondly, that a subgroup of DCIS, which is associated with c-erbB-2 over-expression, exists and appears to have distinct histological features. The subgroup of DCIS cases which over-express c-erbB-2 may be a biologically definable category with prognostic importance. These results may therefore have relevance to breast screening programmes, but a larger study incorporating clinical data would be necessary to correlate these findings with clinical outcome.
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PMID:Immunohistochemical distribution of c-erbB-2 in in situ breast carcinoma--a detailed morphological analysis. 197 59

Amplification of the HER-2/neu proto-oncogene in breast cancer has been reported to correlate with poor patient prognosis. The proliferation, or growth fraction, of cells has also been shown to be of prognostic importance in breast cancer. A study was conducted to evaluate the correlation between HER-2/neu gene expression and proliferation in breast cancer. Quantitative immunohistochemical methods for the detection of the HER-2/neu protein expression and for assessing the proliferation fraction on frozen sections of tumor cells were used. The detection of epidermal growth factor receptor (EGFR) along with quantitative DNA ploidy analysis, also was performed on the same breast cancers. The results indicated two subgroups of invasive ductal carcinoma; 1) HER-2/neu overexpressing cases that were negative for EGFR expression and had low proliferation fraction, and a tetraploid DNA pattern (22 cases), and 2) other combinations of HER-2/neu expression and EGFR expression, with a high proliferation fraction and an aneuploid DNA pattern (38 cases). Eight cases of carcinoma in situ were positive for HER-2/neu overexpression and negative for EGFR expression, and had a high proliferation fraction and a tetraploid DNA pattern. Twenty-six cases of low-grade carcinoma exhibited low proliferation and a diploid DNA pattern.
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PMID:HER-2/neu oncogene expression and proliferation in breast cancers. 197 97

An enzyme-linked immunosorbent assay (ELISA) was developed to measure soluble erbB-2 protein in culture supernatants of various human cell lines and sera of patients suffering from recurrent breast carcinoma. Soluble erbB-2 protein was demonstrated in culture supernatants of cell lines that expressed high levels of erbB-2 protein as shown by western blot analysis of cell lysates. Increased levels of the protein, 40- to 190-fold higher than in healthy controls, were demonstrated in sera of 3 out of 12 patients with breast carcinomas. On immunohistological study of tumor tissues from 9 patients, high immune reaction with the anti-erbB-2 protein antibody was observed in 2 cases. These were two of the three patients who had elevated levels of erbB-2 protein in serum (a sample was not available from the third patient). These results raise the possibility that soluble erbB-2 protein level in serum can be used as an indicator for spread of carcinomas that overexpress erbB-2 protein.
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PMID:In vitro and in vivo release of soluble erbB-2 protein from human carcinoma cells. 197 47

Evidence that the c-erbB-2 proto-oncogene is important in prognosis and oncogenesis in a number of human malignancies is increasing. DNA (Southern) hybridization and immunoblotting (Western) techniques are most commonly utilized to determine the amplification and protein expression of this proto-oncogene, respectively. These extraction techniques are often time consuming, costly, and subject to variability depending on the histological characteristics of the tumor. Immunohistochemistry (IHC), on the other hand, is more often time and cost effective. In addition, IHC may offer enhanced sensitivity over extraction techniques because of the in situ nature of analysis. In data presented here, 71 cases of human mammary carcinoma were concomitantly assessed for c-erbB-2 gene copy number and oncoprotein expression by dilution DNA hybridization and IHC, respectively. In 65 (92%) of 71 cases, high-level expression was associated with gene amplification, whereas moderate or low-level expression was associated with a normal diploid gene copy number. In five of the six discrepant cases, IHC predicted amplification which was not corroborated by Southern analysis. In these cases, tumor mass was limited by the intraductal component of the lesion or by an abundance of stromal elements within the specimen. In 39 of the 71 total cases, Western immunoblotting was compared with IHC in the assessment of oncoprotein expression. Concordance was found in 33 (85%) of 39 cases. In four of the six discrepant cases, high levels of c-erbB-2 expression were demonstrated by IHC but not by immunoblotting. In these cases, intraductal disease and stroma-rich tumors again led to a relative paucity of neoplastic tissue within the specimens. We conclude that IHC offers a favorable alternative to either Southern analysis or Western immunoblotting in the assessment of c-erbB-2 gene copy number and expression levels of oncoprotein in human mammary carcinoma. Furthermore, IHC may prove advantageous to either extraction technique in specimens with limited tumor mass, such as biopsy materials, stroma-rich tumors, or early stage lesions such as intraductal carcinoma.
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PMID:c-erbB-2 expression in breast cancer detected by immunoblotting and immunohistochemistry. 197 42

Seventy specimens of normal endometrium (n = 13) and cervix (n = 12), endometrial hyperplasia (n = 4), cervical dysplasia (n = 20), endometrial (n = 11) and cervical carcinoma (n = 8) and uterine metastases of mammary carcinomas (n = 2) have been analysed for c-erB-2 expression with immunohistochemistry employing a monoclonal anti ERBB-2 antibody and Northern-blot hybridization using single stranded RNA probes. In comparison with the c-erbB-2 mRNA expression level found in normal samples, two advanced and poorly differentiated endometrial adenocarcinomas (FIGO IV) and two ductal mammary carcinomas which had metastasized to the uterus, together with three carcinomas in situ of the cervix, showed c-erbB-2 enhanced transcription level. All other endometrial samples including adenomatous hyperplasia and nine endometrial carcinomas (FIGO I), and all other lesions of squamous epithelial origin displayed transcriptional activities at or below the baseline level. Immunohistochemical study of ERBB-2 protein expression showed staining in most samples, although different in distribution and intensity. Staining of endometrial glands was seen in unevenly distributed cells or cell clusters. In contrast, for endocervical glands, labelling was observed distinctly on basally located cells (reserve cells) and at the subapical side of luminal cells. Faint labelling of the basal cell layer was also observed in squamous epithelia. It was more pronounced in severe cervical dysplasia and carcinoma in situ. In carcinomas of glandular origin, dedifferentiation was accompanied by an increase in cytoplasmic labelling, whereas the intensity of staining was not related to differentiation in squamous cell carcinomas. While data derived from Northern blots are suggestive of c-erbB-2 overexpression to indicate an advanced and dedifferentiated state of tumours of glandular origin, staining with an anti-ERBB-2 antibody occurred in both normal and atypical squamous and glandular epithelia and may indicate regular proliferation and/or differentiation-associated events.
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PMID:Immunohistochemical investigation and northern blot analysis of c-erB-2 expression in normal, premalignant and malignant tissues of the corpus and cervix uteri. 198 Jan 67

The erbB-1 and erbB-2 protooncogenes encode homologous membrane receptors that respectively bind epidermal growth factor (EGF) and a still incompletely characterized ligand. Binding of EGF to its receptor is known to increase tyrosine phosphorylation of the erbB-2/neu receptor in tumor cells. To investigate the mechanism of this transregulatory pathway, we analyzed the interactions between the two receptors in SKBR-3 human breast carcinoma cells. Chemical cross-linking of 125I-labeled EGF revealed that the radiolabeled EGF receptor coimmunoprecipitates with the erbB-2/neu receptor. In addition a cross-linked species of 360-kdalton molecular mass is also coimmunoprecipitated. The formation of the latter species is absolutely dependent on the presence of EGF receptor and thus appears to represent a heterodimer of the erbB-1 and erbB-2 receptors. In vitro kinase reaction assays revealed that receptor heterodimerization is induced by EGF binding and leads to a dramatic increase in the self-phosphorylation capacity of the dimerized receptors. Moreover, analysis of living SKBR-3 cells suggested that most of the EGF-induced transregulation of the erbB-2/neu receptor is due to receptor heterodimerization. In conclusion, heterodimers of erbB-1 and erbB-2 receptors may provide a mechanism for dual transductory functions of growth factors of breast tumor cells.
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PMID:Heterodimerization of the erbB-1 and erbB-2 receptors in human breast carcinoma cells: a mechanism for receptor transregulation. 198 Feb 16

Overexpression of the epidermal growth factor (EGF) receptor (c-erbB) proto-oncogene is a frequent occurrence in human carcinoma and appears to accompany autocrine or paracrine transforming growth factor-alpha expression, which in model systems can result in activation of EGF receptor tyrosine kinase activity and phenotypic transformation. Here we have investigated the transcriptional regulation of the EGF receptor gene, by run-on transcription in isolated nuclei derived from epithelioid tumor lines. The level of transcription was measured at various points on the 100-kilobase pair EGF receptor gene locus, on either sense or antisense DNA strands. We find the level of sense strand transcription along exon 1 is 8-fold higher than transcription in exons 2-26. Primary EGF receptor transcripts appear to pause or terminate prematurely between exons 1 and 2. Termination was mapped to a sequenced region approximately 2 kilobase pairs 3' of exon 1, proximal to a previously reported DNase I hypersensitive site and an enhancer-like activity. Transcription in the CpG-rich region surrounding exon 1 is bidirectional, with antisense transcripts initiating in intron 1 and extending through the coding first exon. Activation of protein kinase C results in a 5-fold induction of EGF receptor transcription, accompanied by a slow release in the block RNA elongation between exon 2 and exon 26, showing that EGF receptor RNA synthesis may be altered by changes in de novo transcription and by a block to RNA elongation.
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PMID:Contributory effects of de novo transcription and premature transcript termination in the regulation of human epidermal growth factor receptor proto-oncogene RNA synthesis. 198 48


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