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)

Mutant p53 tumour suppressor gene and c-erbB-2 proto-oncogene are involved in human carcinogenesis, and their protein product detection in human malignancies might influence the evolution of many neoplasms. Our aim was to estimate their association with histopathological and clinical parameters of prognostic value in colorectal cancer. An immunohistochemical assay was undertaken in formalin-fixed sections from tissue specimens of 60 colorectal carcinomas. Nuclear p53 expression was detected in 46.6%, while membranic c-erbB-2 positivity was noticed in 35% of the examined cases. P53 positivity rate significantly correlated with poor differentiation (p < 0.001), high mitotic activity (p < 0.0001), tumour stage (p < 0.001) and 5-year overall survival period (p < 0.01). C-erbB-2 positivity incidence significantly correlated with advanced Dukes' stage (p < 0.001) and high mitotic activity (p < 0.05). Significant association between p53 and c-erbB-2 immunostaining was observed (p < 0.05) and p53/c-erbB-2 co-expression was related to poor differentiation (p < 0.001), high mitotic activity (p < 0.001), advanced Dukes' stage (p < 0.001), tumour aneuploidy (p < 0.05) and worse overall survival (p < 0.05). P53 and c-erbB-2 immunohistochemical detection in combination with known prognostic indicators may be a useful future tool in determining colorectal cancer prognosis and subsequently in deciding on optimal postoperative treatments.
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PMID:Prognostic significance of p53 and c-erbB-2 immunohistochemical evaluation in colorectal adenocarcinoma. 757 15

Administration of a single i.v. injection of 50 mg N-methyl-N-nitrosourea (MNU)/kg body wt to 50- to 60-day old virgin rats, 120-day-old virgin rats, and 120-day-old parous rats (Sprague-Dawley; n = 18-37) resulted in a high incidence of mammary carcinomas in the virgin animals (97.3% in 50- to 60-day-old virgin rats; 75.0% in 120-day-old virgin rats), but mammary carcinomas did not develop in the parous rats. The concentrations in serum of various mammotropic hormones were measured in identical groups of rats at the time of MNU treatment. Growth hormone (GH) concentration was significantly reduced in parous rats, as compared with young or age-matched virgin rats. The concentrations of prolactin, 17 beta-estradiol, progesterone, corticosterone and thyroxine were not significantly altered in the parous rats compared to the two groups of virgin animals. Histological examination of the mammary glands from the three groups of rats showed that the epithelia of the parous animals were in a stage of regression, whereas the mammae of the young virgin rats showed the highest degree of lobulo-alveolar development. The levels of estrogen receptor (ER), epidermal growth factor (EGF) receptor (EGF-R) and GH receptor (GHR) in the mammary glands of the animals were also measured. We found a reduction in the receptor levels for both estrogen and EGF in mammary tissues from parous animals. Receptors for GH were present in normal mammary tissues from both virgin and parous rats. We hypothesize that the reduction in the circulating concentration of GH caused the reduced susceptibility of parous rats to mammary carcinogenesis possibly by decreasing the levels of ER and/or EGF-R in the mammary gland.
Carcinogenesis 1995 Nov
PMID:Refractoriness to mammary tumorigenesis in parous rats: is it caused by persistent changes in the hormonal environment or permanent biochemical alterations in the mammary epithelia? 758 8

Gastric cancer involves changes in multiple oncogenes and multiple suppressor genes, and it causes genetic instability. Aberrant expression and amplification of the c-met gene, inactivation of the p53 gene, and CD44 abnormal transcripts are common events of both well differentiated and poorly differentiated gastric cancers. Amplification of the cyclin E gene is also observed in gastric cancer regardless of histologic type. Decreased expression of the pic1 (p21) gene occurs independent of the p53 mutations. In addition, K-ras mutations, c-erbB-2 gene amplification, loss of heterozygosity (LOH) and mutations of the APC gene, LOH of the bcl-2 gene, and LOH at the DCC locus are preferentially associated with well differentiated gastric cancer. Moreover, LOH on chromosome 1q is involved in the progression of well differentiated cancer. Precancerous lesions, including hyperplastic polyp, intestinal metaplasia, and adenoma, share genetic changes found in well differentiated cancers. Conversely, genetic instability may be involved in the first step of stomach carcinogenesis of the poorly differentiated type. Reduction or loss of cadherin and catenins, K-sam gene amplification, and c-met gene amplification are necessary for the development and progression of poorly differentiated or scirrhous carcinoma. Interaction between cell-adhesion molecules in the c-met expressed tumor cells and hepatocyte growth factor from stromal cells is implicated in the morphogenesis of two types of gastric cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Molecular biology of gastric cancer. 767 88

Little is known about the molecular mechanisms of lung carcinogenesis in women. We initiated an investigation of the role of gender in pulmonary carcinogenesis by analysis of p53 mutations, immunohistochemistry, serum antibodies and c-erbB-2 expression in a series of 63 male and 44 female lung cancer patients whose tumors were resected at the Mayo Clinic between 1991 and 1992. There were 102 smokers and 5 never smoked. Adenocarcinoma was the more frequent histological type in women (62%) than in men (41%). Sequence analysis of exons 5-8 in 42 females and 49 males identified 44 p53 mutations in 42 tumors (46%). Base substitution mutations showed a preponderance of G:C-->T:A transversions, which were more frequent in women than men (40 versus 25%) and in individuals exposed to asbestos. c-erbB-2 immunohistochemical staining was identified more frequently in females (nine cases) than males (two cases). Marked immunohistochemical staining for p53 positively correlated with the presence of missense mutations in exons 5-8 (81%, P < 0.001). Seven missense mutations (four in exon 5, two in exon 6, one in exon 8) were identified in five of nine patients who had serum antibodies recognizing p53; tumors from these patients were also strongly positive for p53 by immunohistochemistry. These and other results indicate gender differences in the genetic and biochemical alterations in lung cancer and generate hypothesis regarding gender differences in lung cancer susceptibility.
Carcinogenesis 1995 May
PMID:Gender comparisons in human lung cancer: analysis of p53 mutations, anti-p53 serum antibodies and C-erbB-2 expression. 776 98

The human c-erbB-2 oncogene is homologous to the rat neu oncogene, both encoding transmembrane growth factor receptors. Overexpression and point mutations in the transmembrane domain of the encoded proteins in both cases have been implicated in cell transformation and carcinogenesis. In the case of the neu protein, it has been proposed that these effects are mediated by conformational preferences for an alpha-helix in the transmembrane domain, which facilitates receptor dimerization, an important step in the signal transduction process. To examine whether this is the case for c-erbB-2 as well, we have used conformational energy analysis to determine the preferred three-dimensional structures for the transmembrane domain of the c-erbB-2 protein from residues 650 to 668 with Val (nontransforming) and Glu (transforming) at position 659. The global minimum energy conformation for the Val-659 peptide from the normal, nontransforming protein was found to contain several bends, whereas the global minimum energy conformation for Glu-659 peptide from the mutant, transforming protein was found to be alpha-helical. Thus, the difference in conformational preferences for these transmembrane domains may explain the difference in transforming ability of these proteins. The presence of higher-energy alpha-helical conformations for the transmembrane domain from the normal Val-659 protein may provide an explanation for the presence of a transforming effect from overexpression of c-erbB-2. In addition, docking of the oncogenic sequences in their alpha-helical and bend conformations shows that the all-alpha-helical dimer is clearly favored energetically over the bend dimer.
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PMID:Conformation of the transmembrane domain of the c-erbB-2 oncogene-encoded protein in its monomeric and dimeric states. 777 61

To investigate the molecular mechanism of gastric carcinogenesis, we examined simultaneously the frequency of microsatellite instability and the immunoreactivities to ras, erbB-2, and p53 in 42 gastric adenocarcinoma tissues. Microsatellite instability, measured by DNA replication error, was detected in 33.3% (14/42) of patients with gastric carcinoma while positive immunostaining was demonstrated in 3.1% (1/32) for ras, 40.5% (17/42) for erbB-2, and 28.6% (12/42) for p53. There was no statistical difference between the intestinal type and the diffuse type of carcinoma with respect to microsatellite instability, ras, or erbB-2 expression. The expression of p53 occurred more frequently in the intestinal type of carcinoma (41.7%, 10/24) than in the diffuse type of carcinoma (11.1%, 2/18; P < 0.01). There was no association between microsatellite instability and ras or p53 expression, while enhanced expression of erbB-2 occurred more frequently in carcinomas with microsatellite instability (64.3%, 9/14) than in those without microsatellite instability (28.6%, 8/28; P < 0.05). Such a strong association between microsatellite instability and erbB-2 oncogene may be responsible for the increase of other oncogenic mutations and tumor progression in gastric carcinogenesis.
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PMID:Occurrence of microsatellite instability in gastric carcinoma is associated with enhanced expression of erbB-2 oncoprotein. 788 46

A link between inflammation of the colon in inflammatory bowel disease (IBD) and the increased risk of colon cancer in ulcerative colitis (UC) may be provided by growth factor receptor genes. Their expression may be altered in response to growth factors present in the mucosa, and this, in turn, may induce further genetic changes, linked to carcinogenesis, in the cells of the colonic epithelium. To test this hypothesis, we assayed steady-state levels of eight growth factor receptor mRNAs in colonic epithelial cells of IBD patients and controls. Four of these genes (EGF-R, IGFI-R, CSF1-R, and PDGF-R-beta) were expressed in epithelial cells, whereas four (erbB-2, erbB-3, NGF-R, and met) were not. The level of the former in involved or uninvolved IBD was considerably lower than in normal epithelial cells from either sporadic colon cancer or diverticulitis patients. In contrast, expression was much higher in IBD patients with colon tumors than in active chronic IBD. The level of PDGF-R-beta mRNA was two- to fourfold higher in involved than in uninvolved areas of the colons of two UC patients, but not in one Crohn's disease patient. Message abundance of its ligand, PDGF-beta, however, was the same in paired UC samples. The pattern of expression of PDGF-beta and cripto was identical to that of EGF-R, whereas the level of mRNA of amphiregulin was the same in active chronic IBD and IBD patients with tumors. A fourth growth factor, Kfgf, was not expressed. Increased levels of PDGF-R-beta mRNA in involved UC relative to uninvolved UC may be related to the disease process in UC. Decreased expression of growth factor- and growth factor receptor-encoded mRNA in active chronic IBD may be related to the disease process, or it may be an effect of steroid therapy undergone by these patients. Enhanced expression of these genes in IBD patients with tumors compared to those without tumors suggests that this may be a marker for development of colon cancer in IBD.
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PMID:Expression of growth factor receptor-encoded mRNA by colonic epithelial cells is altered in inflammatory bowel disease. 789 32

Point mutations of the transmembrane domain coding region of the neu proto-oncogene in N-nitroso-N-ethylurea-induced hamster neurofibromas were found at high frequency (93%; 14 of 15). They involved codons 659 as well as 658, the latter not having been reported previously in rat tumors. The mutational change was seen even in the early stage neurofibroma. On the other hand, no mutations were detected in melanomas or Wilms' tumors induced in the same N-nitroso-N-ethylurea-treated animals, even when the melanomas demonstrated extensive schwannian differentiation. Moreover, any human Schwann cell tumors including neurofibroma, schwannoma, and malignant schwannoma did not show the mutation of c-erbB-2 gene (0 of 34), which is homologous to the hamster neu. Since high expression of neu mRNA is evident in the hamster Schwann cell at the late gestational and neonatal stages, transplacental administration of N-nitroso-N-ethylurea is considered to interact directly to carcinogenesis of the hamster Schwann cell through neu gene mutation.
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PMID:neu proto-oncogene mutation is specific for the neurofibromas in a N-nitroso-N-ethylurea-induced hamster neurofibromatosis model but not for hamster melanomas and human Schwann cell tumors. 790 99

Over-expression of the c-erbB-2 oncogene-encoded p185 protein product has been implicated in the pathogenesis of a wide variety of human malignancies, including lung cancer. Over-expression of p185 can be detected immunologically by quantification of the extracellular domain of p185 (c-erbB-2 oncopeptide) in extracellular fluid in vitro and in serum in vivo. An enzyme-linked immunosorbent assay (ELISA) for the c-erbB-2 oncopeptide was used to examine banked serum samples of 11 pneumoconiosis patients who subsequently developed lung cancer and serum samples from 11 hospital controls matched for age, sex, ethnic group and smoking as well as 55 unmatched general population controls. The mean serum level for the c-erbB-2 oncopeptide in human neu units/ml in the lung cancer cases (1,756 +/- 549 HNU/ml) was statistically significantly elevated (p < 0.001) in comparison to the mean level in the matched controls (976 +/- 488 HNU/ml) or the general population controls (888 +/- 655 HNU/ml). Defining a positive elevation of the serum c-erbB-2 oncopeptide as any value more than 2 standard deviations above the mean of the matched controls, 64% (7 of 11) of the lung cancer cases were positive compared to 0% (0 of 11) matched controls and 5% (3 of 55) of the unmatched controls. In addition, 4 of the 7 c-erbB-2 oncopeptide-positive cancer cases had positive serum samples prior to the time of disease diagnosis (average = 35 months). These results suggest that serum c-erbB-2 oncopeptide may be elevated at an early stage of pulmonary carcinogenesis and that further prospective study of the utility of this biomarker is warranted.
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PMID:Detection of increased amounts of the extracellular domain of the c-erbB-2 oncoprotein in serum during pulmonary carcinogenesis in humans. 790 54

To verity the role of metastasis-related nm23 genes in carcinogenesis and progression of ovarian carcinoma, we analyzed the mRNA levels of the nm23 genes of both isoforms, -H1 and -H2, together with those of the epidermal growth factor receptor, the c-erbB-2, and the c-erbB-3 genes in 45 ovarian carcinomas and 5 benign cystadenomas. Expressions of nm23 gene products/nucleoside diphosphate kinases, epidermal growth factor receptor, erbB-2 protein, and sex steroid receptor status in ovarian carcinomas were also examined by immunohistochemistry. The mRNA levels of nm23-H1 and nm23-H2 were higher in carcinoma tissues compared with benign tumors (H1, P < 0.01). The mRNA levels of c-erbB-2 and c-erbB-3 were also elevated in carcinoma tissues, and there was a positive correlation between mRNA levels of the nm23-H1 and the c-erbB-2 genes (r = 0.58; P < 0.05). Correlation of immunohistochemical staining between nucleoside diphosphate kinases and erbB-2 protein was also observed in ovarian carcinoma tissues. Sex steroid receptor positivity was related to a higher expression of nucleoside diphosphate kinases. Expression levels of the nm23 genes in ovarian carcinomas were not related to either histological subtype or local extension and peritoneal dissemination. Among stage III ovarian carcinomas, however, tumors possessing lymph node metastasis showed significantly lower nm23-H1 mRNA levels than those without nodal involvement (P < 0.05). Stage IV carcinomas also exhibited lower nm23-H1 and nm23-H2 expression levels compared with other stages (P < 0.05). These results suggest that expression of the nm23 genes, especially nm23-H1, is activated, accompanied by c-erbB-2 and c-erbB-3 overexpressions, in early stages of the carcinogenic process of ovarian carcinoma and reduction of nm23-H1 expression occurs in association with lymph nodal and/or distant metastasis.
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PMID:Expression of metastasis-related nm23-H1 and nm23-H2 genes in ovarian carcinomas: correlation with clinicopathology, EGFR, c-erbB-2, and c-erbB-3 genes, and sex steroid receptor expression. 790 45


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