Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HER2 or c-erbB-2 is a putative growth factor receptor with sequence homology to the epidermal growth factor receptor. It is the human homologue of the rat protooncogene neu and may have an important role in human malignancies such as breast and ovarian cancers. Like other growth factor receptors, HER2 has intrinsic protein tyrosine kinase activity and undergoes autophosphorylation. Recently, we have demonstrated that, similar to the epidermal growth factor receptor, all autophosphorylation sites of HER2 are localized in the carboxyl terminus of this protein. In the present study, immunopurified HER2 was allowed to autophosphorylate, and tryptic phosphopeptides were generated. After purification of these phosphopeptides by high performance liquid chromatography, microsequencing was performed. Utilizing this approach, two autophosphorylation sites were unequivocally identified at Y1023 and Y1248. The sequences of two other tyrosine phosphorylated tryptic peptides were determined, but the exact site of autophosphorylation could not be determined because multiple tyrosines were located on each peptide. However, each of these peptides contains tyrosines that correspond to major autophosphorylation sites of the epidermal growth factor receptor, suggesting that, in addition to Y1023 and Y1248, Y1139 and Y1222 also serve as autophosphorylation sites of HER2.
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PMID:Identification of autophosphorylation sites of HER2/neu. 170 16

Diagnosis- and/or prognosis-related alterations of (proto) oncogenes may be detected in neuroblastoma (N-myc), carcinoma of breast and ovary (HER2/neu), NHL (c-myc, bcl-2), CML (c-abl/bcr), and some other neoplasias. A wide variety of methods for the detection of gene alterations can be applied. The methods of detection have to be chosen according to the expected mechanisms of oncogene activation, the availability of adequately prepared tissue, and the technical standard of the laboratory. The sensitivity, specificity, and quantitation of morphological techniques (immunohistochemistry and in situ hybridization) is restricted and their results have to be interpreted most carefully. Whenever possible, at least two different techniques should be used, preferably on two different levels, i.e. RNA/DNA and protein. Furthermore, the combination of morphological and non morphological methods should be aspired.
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PMID:[Oncogenes and oncogene products--possibilities and significance of their detection]. 170 8

The ERBB2 (also called HER2, neu, and c-erbB-2) gene product, which encodes a growth factor receptor, was implicated in the malignancy of human adenocarcinomas. An antibody directed to the rat oncogenic receptor has been previously shown to have an antitumor effect in model systems. In an attempt to extend this observation to the protooncogenic human receptor and also to understand the underlying mechanism, we generated a panel of monoclonal antibodies specific to the extracellular portion of the ERBB2 protein. The effects of the antibodies on tumor growth were compared with their cellular and biochemical actions in vitro. Surprisingly, opposing in vivo effects were observed: although some antibodies almost completely inhibited the growth in athymic mice of transfected murine fibroblasts that overexpress Erbb-2, other antibodies either accelerated tumor growth or resulted in intermediate responses. When tested on cultured human breast carcinoma cells or ERBB2 transfectants, the tumor-stimulatory antibody was found to induce significant elevation of tyrosine phosphorylation of the ERBB2 protein. In contrast, only partial correlation was observed between the capacity to restrict tumor growth and the effects of the antibodies on receptor degradation and cellular proliferation in vitro. This suggests that the antitumor antibodies affect both receptor function and host-tumor interactions. Our results may help establish experimental criteria for the selection of specific antibodies for use either alone or in conjunction with other molecules as pharmacological antitumor agents.
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PMID:Mechanistic aspects of the opposing effects of monoclonal antibodies to the ERBB2 receptor on tumor growth. 171 84

Amplification of the c-myc and HER2/neu genes was found in 20 and 23%, respectively, of primary breast cancer tissues derived from 282 patients (median follow-up, 74 months). c-myc amplification was observed more frequently in larger tumors (P = 0.01) and in lymph node-positive patients (P = 0.01) but was not associated with age, menopausal status, or with differentiation grade or steroid receptor status. c-myc amplification was strongly negatively correlated with HER2/neu amplification (P less than 0.001). In univariate analysis, amplification of c-myc proved to be a significant predictor of reduced relapse-free and overall survival (for both, P less than 0.001). In multivariate analysis for relapse-free survival, c-myc amplification significantly (P = 0.001) added to the prognostic power of tumor size (P less than 0.001), lymph node status (P less than 0.001), and estrogen receptor status (P = 0.003), with the highest relative failure rate (1.8) after lymph node status (2.2). In this pilot study, c-myc amplification was predictive for outcome, especially among patients with node-negative disease or steroid receptor-positive tumors; 51 and 46% differences in actuarial 5-year recurrence rates when compared to patients with tumors with normal c-myc gene copy numbers, respectively. HER2/neu amplification was not associated with relapse-free survival but weakly with shorter overall survival in univariate analysis (P = 0.035). Only in the relatively small subgroup of steroid receptor-negative tumors, HER2/neu amplification may identify those patients with an increased risk of death. In conclusion, amplification of c-myc is an independent powerful prognosticator, particularly in node-negative and steroid receptor-positive breast cancer, whereas HER2/neu amplification may be of limited prognostic value, only in steroid receptor-negative disease.
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PMID:c-myc amplification is a better prognostic factor than HER2/neu amplification in primary breast cancer. 173 70

ONGC's Hazira Gas-Processing Complex (HGPC) consists of facilities for receiving natural gas along with associated condensate from an off-shore field at a rate of 20 MMN M3 per day. After separating the condensate, which is processed in condensate fractionation units, the gas is processed through various steps to recover LPG and to reduce its dew point to less than 5 degrees C in order to make it suitable for transportation over long distances. The acid gas recovered during the gas-sweetening step is processed to obtain sulphur. The major products manufactured at HGPC therefore are lean sweet gas, LPG, NGL, and sulphur. The Oil and Natural Gas Commission awarded the assignment on Hazard Study and Risk Analysis of their Hazira Gas-Processing Complex (HGPC) to the Council of Scientific and Industrial Research (CSIR) in association with the Netherlands Organisation for Applied Scientific Research (TNO). The scope of this assignment covered a number of closely related and fully defined activities normally encountered in this type of work. Identification of hazards through the most appropriate methods, assigning frequency of occurrence of major unwanted incidents, quantification and assessment of probable damage to plant equipment, environment, human and animal life due to an unexpected event, and evaluation of various methods for reducing risk, together constituted the methodology for this assignment. Detailed recommendations aimed at reducing risk and enhancing reliability of plant and machinery were made. This article gives an overview of the assignment.
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PMID:Risk analysis of a gas-processing complex in India. 194 47

Based on the high incidence of loss of heterozygosity for loci on chromosome 17p in the vicinity of the p53 locus in human breast tumors, we investigated the frequency and effects of mutations in the p53 tumor suppressor gene in mammary neoplasia. We examined the p53 gene in 20 breast cancer cell lines and 59 primary breast tumors. Northern blot analysis, immunoprecipitation, and nucleotide sequencing analysis revealed aberrant mRNA expression, over-expression of protein, and point mutations in the p53 gene in 50% of the cell lines tested. A multiplex PCR assay was developed to search for deletions in the p53 genomic locus. Multiplex PCR of genomic DNA showed that up to 36% of primary tumors contained aberrations in the p53 locus. Mutations in exons 5-9 of the p53 gene were found in 10 out of 59 (17%) of the primary tumors studies by single-stranded conformation polymorphism analysis. We conclude that, compared to amplification of HER2/NEU, MYC, or INT2 oncogene loci, p53 gene mutations and deletions are the most frequently observed genetic change in breast cancer related to a single gene. Correlated to disease status, p53 gene mutations could prove to be a valuable marker for diagnosis and/or prognosis of breast neoplasia.
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PMID:Mutations in p53 as potential molecular markers for human breast cancer. 196 33

The human homolog of the rat neu oncogene, HER2 (also termed c-erbB2) has been demonstrated in amplified form in human breast tumors with poor prognosis. Although amplification of the gene correlates with expression of a 185-kDa transmembrane glycoprotein, no extensive information is available regarding the extent of tissue and tumor specificity of this gene product. We have addressed this issue by immunohistochemically evaluating the expression of p185 HER2 in normal tissue and various tumors using monoclonal antibodies (MAbs) to distinct epitopes of its extracellular domain. No detectable levels of p185 HER2 were found in fetal tissues analyzed, with the exception of renal tubules in 2 out of 3 specimens tested and in intestinal epithelium. In adult tissues, detectable levels of this glycoprotein were found in a restricted number of cell types, the expression being heterogeneous among individuals and cell histotypes. Among the neoplasms assayed p185 HER2 was expressed in 46% of primary breast cancers, in 28% of ovarian tumors and in 30% of colon rectum malignancies. No male breast adenocarcinomas were p185-positive. A large number of other tumors tested revealed only a low incidence of expression of the p185. In metastatic breast tumors p185 HER2 was demonstrated homogeneously among multiple autologous lesions and almost invariably (80%) the expression of p185 in the primary lesion correlated with that of the deriving metastases. Our findings indicate that the expression of the p185 HER2 represents a tumor marker of clinical relevance in breast cancer. Whether this holds true for other malignancies remains to be explored.
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PMID:Expression of the p185 encoded by HER2 oncogene in normal and transformed human tissues. 196 37

The neu proto-oncogene product has been found to exist in two interconvertible forms in G8/DHFR mouse fibroblasts. The 185-kilodalton form (p185) present in growing cells is replaced by a 175-kilodalton form (p175) under conditions of serum starvation. This low molecular weight form accounts almost exclusively for the phosphotyrosine content of the receptor and is associated with increased tyrosine kinase activity. Addition of serum, platelet-derived growth factor or tumor promoter induces conversion of p175 to p185 within minutes, and this increase in molecular weight is associated with phosphorylation of serine and threonine; removal of serum growth factors is followed by replacement of p185 with p175 over several hours. Unlike G8/DHFR cells, the human breast cancer cell line SK-Br-3 expresses a high molecular weight neu/HER2 receptor with unchanged phosphotyrosine content in both serum-starved and serum-stimulated cultures. These findings indicate that activation of the neu proto-oncogene product in G8/DHFR cells may be regulated in part by protein kinase C-mediated receptor transmodulation rather than by ligand availability alone.
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PMID:Modulation of a Mr 175,000 c-neu receptor isoform in G8/DHFR cells by serum starvation. 197 80

Expression of the oncogenes, epidermal growth factor (EGF) receptor, HER2/neu, c-myc, and c-fos, in renal cell carcinoma and corresponding nonneoplastic kidney tissue of 30 patients has been analyzed by Northern blot analysis. In renal cell carcinoma an inverse relationship of EGF receptor and HER2/neu gene expression was detected, with high expression of the EGF receptor gene in 22 of 30 (73%) cases and low expression of the HER2/neu gene in 28 of 30 (93%) cases. Furthermore, altered expression of the oncogenes c-myc and c-fos was detected in renal cell carcinoma, which appears to be related to the tumor grade of malignancy. Additional Southern blot analysis of six renal cell carcinomas gave no indication of chromosomal rearrangement events or gene amplification.
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PMID:Inverse relationship of epidermal growth factor receptor and HER2/neu gene expression in human renal cell carcinoma. 197 62

p185neu is the protein product of the HER2/neu protooncogene. This protein has characteristics of a tyrosine kinase growth factor receptor and is postulated to be important in human carcinogenesis. To define the significance of the expression of this protein in human non-small cell lung cancer, 55 tumors from patients with squamous cell carcinoma (16), adenocarcinoma (29), or large cell carcinoma (10) of the lung were examined for p185neu using immunohistological methods. Five of 16 squamous cell carcinomas and 10 of 29 adenocarcinomas were found to overexpress p185neu relative to levels of expression seen in uninvolved bronchiolar epithelium. For the adenocarcinomas, p185neu expression was associated with older age (66.6 +/- 10.1 versus 57.5 +/- 10.8 years) (P = 0.04) and shortened survival (83.7 +/- 94.1 versus 188.5 +/- 120 weeks) (P = 0.01). In this group, using Cox's multivariate survival analysis, p185neu expression was found to be a significant determinant of survival (P = 0.04) even after accounting for the effect of tumor stage. For the squamous cell carcinomas, p185neu expression was not correlated with any of our clinicopathological parameters. Our findings indicate that non-small cell lung cancers which express p185neu do so at levels higher than that found in normal bronchiolar epithelium, and expression in adenocarcinomas of the lung is independently associated with diminished survival intervals.
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PMID:p185neu expression in human lung adenocarcinomas predicts shortened survival. 197 68


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