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 ras gene product (p21) is a GTP-binding protein and has been thought to transduce signals regulating proliferation or differentiation of cells. Like other GTP-binding proteins, p21.GTP is an active conformation, which can transduce the signals downstream, whereas p21.GDP is an inactive one. Recently, we have shown that p21.GTP levels increased in cells treated with fetal bovine serum or platelet-derived growth factor to initiate DNA synthesis. In this paper, we report that epidermal growth factor can also increase the amounts of p21.GTP in the cells. Effects of epidermal growth factor and platelet-derived growth factor are not additive. In contrast, mutant [Val12]p21, which has transforming activity, responded neither to platelet-derived growth factor nor to epidermal growth factor. We also found that the ratio of p21.GTP to p21.GDP increased 3- to 4-fold in transformants carrying activated erbB-2/neu or v-src oncogenes. These results strongly suggest an important role of p21 in transduction of signals for both normal proliferation and malignant transformation through growth factor receptors with tyrosine kinase activity or related oncogene products.
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PMID:Accumulation of p21ras.GTP in response to stimulation with epidermal growth factor and oncogene products with tyrosine kinase activity. 214 78

Multi-autocrine loops of the epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), platelet-derived growth factor (PDGF) and TGF beta system are expressed in human gastrointestinal carcinomas. In esophageal and gastric carcinomas, they evidently play an important role in tumor progression. Gastrin, one of the major gut hormones, may also act as an autocrine growth factor for gastric and colonic carcinomas. The HST1 and INT-2 genes, belonging to the fibroblast growth factor gene family, are coamplified in approximately 50% of primary tumors and in all the metastatic tumors of esophageal carcinoma. TGF alpha and EGF are the ligands of the tumor cells that overexpress EGF receptor in esophageal carcinomas. The synchronous expression of EGF and its receptor, as well as TGF alpha and ras p21, is evidently correlated with the depth of tumor invasion, metastasis and prognosis of gastric carcinomas. Amplification of c-erbB-2 and EGF receptor genes has been observed in many metastatic sites of gastric carcinomas regardless of histological type. In addition to TGF alpha and EGF, TGF beta and PDGF A chain produced by tumor cells may stimulate collagen synthesis not only by fibroblasts but also by tumor cells themselves, resulting in extensive progression and diffuse fibrosis of scirrhous gastric carcinomas. Moreover, TGF alpha or EGF and estrogen may also play a cooperative role in the development of scirrhous gastric carcinoma. In colorectal carcinoma, it has been shown that the accumulation of several alterations in ras genes and p53 genes is most important for the conversion of adenoma to carcinoma. Critical genetic changes, including activation of oncogenes, mutation and deletion of tumor suppressor genes and disturbances in transcriptional regulatory sequences, may bring about aberrant expression of growth factors and their receptors in gastrointestinal carcinomas. The understanding of the significance of EGF-related growth factors in tumor progression provides a framework for a biological approach to the therapy of human gastrointestinal carcinomas. 8-Cl-cAMP, which inhibits expression of oncogenes and TGF alpha, may be useful not only for cancer therapy but also for the study of cell differentiation.
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PMID:Growth factors and oncogenes in human gastrointestinal carcinomas. 215 13

The localization of DNA replicating cells, epidermal growth factor (EGF) receptor-expressing cells and ras oncogene product p21 (p-21ras) positive cells were examined in various skin tumours to elucidate the role of EGF receptor and p21ras in the epidermis. Normal skin, keratoacanthoma (KA), solar keratosis (SK), Bowen's disease (BD), squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and extramammary Paget's disease (PD) were studied. EGF receptors were seen in proliferating layers, where DNA replicating cells localize, but p21ras was found in the more differentiated layers. We conclude that EGF receptor expression is closely associated with cellular proliferation, but p21ras may play a role in the differentiation of cells in various skin tumours.
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PMID:Association of EGF receptor expression with proliferating cells and of ras p21 expression with differentiating cells in various skin tumours. 220 27

Two cell lines (University of Michigan squamous carcinoma of the vulva UM-SCV-1A and UM-SCV-1B) were established from the primary tumor and a malignant pleural effusion of a 62-year-old woman. Both tumor specimens grew vigorously in vitro and could be passaged after only 14 and 10 days in culture, respectively. Both cell lines undergo 3 population doublings in 4 days, reaching saturation densities of 5 x 10(5) cells/cm2, and have been carried through more than 30 in vitro passages. In nude mice the cultured cells initially formed tumors but these regressed 2-3 weeks after inoculation. The regressing mouse tumors consisted of poorly differentiated squamous carcinoma surrounded by an inflammatory lymphoid infiltrate. The UM-SCV-1 cell lines express membrane antigens typically displayed by squamous-cell carcinomas. These include the HLA class-1 light chain beta 2-microglobulin, pemphigus, pemphigoid, and the alpha 6 beta 4 integrin defined by the UM-A9 monoclonal antibody (MAb). In contrast to the A431 vulvar carcinoma, these tumor lines do not have amplified expression of the epidermal growth factor (EGF) receptor. Although tissue from the primary tumor contained low levels of estrogen receptor activity, no receptor activity was detected in the cell lines. Nevertheless, both lines were sensitive to growth inhibition by tamoxifen. This effect was not reversible by estradiol, indicating an estrogen-receptor-independent mechanism. The tumors were both hypotetraploid, contained the same chromosome rearrangements and had stable karyotypes in vitro. Each contained inv(1)(p36.3q32.1), del(4)(q12), dic(4;11)(q12;p11.2), i(5p), der(6)t(3;6)(q25.1;p21.1), several rearrangements involving chromosomes 8 and 14, + i(13), i(18p), a dicentric t(11;19), and 2 or 3 unidentified markers. Since the karyotypes of both tumors were the same, no major karyotypic change was associated with metastatic spread. These paired primary and metastatic SCC lines from an unusually aggressive vulvar carcinoma provide an in vitro model for analysis of the biological basis of this tumor's behavior.
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PMID:Phenotypic characterization, karyotype analysis and in vitro tamoxifen sensitivity of new ER-negative vulvar carcinoma cell lines, UM-SCV-1A and UM-SCV-1B. 233 95

MCF-7 human breast cancer cells are estrogen dependent for maximal in vitro growth and for tumor formation in nude mice, thus providing a useful model system to study mammary tumorigenesis. A clone of MCF-7 cells transfected with the v-rasH oncogene has been shown to form tumors in the absence of estradiol [Kasid et al., 1985, Science (Wash. DC), 228:725-728]. To extend this observation to more clones of v-rasH-expressing MCF-7 cells and to examine the effects of rasH mutation, we transfected MCF-7 cells with a construct encoding the human c-rasH protooncogene protein product and with three isogenic constructs encoding proteins containing point mutations: arg-12, thr-59, and arg-12 + thr-59 (v-rasH). We isolated several cell lines which produced levels of c-rasH and v-rasH p21 at 30- to 50-fold the levels of controls. We also isolated several cell lines producing the various mutants p21s. All of the transfected cell lines were estrogen-responsive for cell growth. Transfected cells containing high levels of rasH p21 had correspondingly high levels of growth in an anchorage-independent growth assay. Tumorigenesis studies in nude mice, however, showed that some, but not all of the cell lines expressing v-rasH, formed tumors in the absence of estradiol. Tumor formation did not correlate with the level of rasH p21 expression in these cell lines. No tumor formation in the absence of estradiol was observed for cell lines expressing single-mutated or unmutated forms of rasH.
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PMID:Growth properties and tumorigenesis of MCF-7 cells transfected with isogenic mutants of rasH. 240 19

Alteration of oncogene and loss of chromosomal heterozygosity are infrequent in human gastric carcinoma compared with those in other gastrointestinal carcinomas. Amplification of c-erbB-2 gene is observed in well differentiated adenocarcinoma, while sam gene is found in poorly differentiated adenocarcinoma or scirrhous carcinoma. sam gene, which was isolated from a gastric cancer cell line KATO-III by a DNA renaturation method, encodes tyrosine-specific protein kinase domain. A good correlation evidently exists between the synchronous expression of TGF alpha and ras p21 and biological malignancy of gastric carcinoma. c-myc and c-fos proteins are found not only in tumor cells but also in stromal cells including macrophages and fibroblast around the tumors. The prognosis of patients with c-myc p 62-positive stromal cells is significantly better than that of patient with p 62-negative stromal cells. Coamplification of the hst-1 gene and int-2 is observed in 50% of primary tumors and all metastatic tumors of esophageal carcinoma. PCR (polymerase chain reaction) technique seems to be useful for the detection of oncogene point mutation in human gastric carcinoma.
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PMID:[Oncogenes in human gastric carcinoma]. 254 46

The expression of ras, c-myc and c-erbB-2 oncoproteins in 100 human (73 ductal and 27 lobular) breast carcinomas has been examined using an immunohistochemical analysis. The monoclonal antibody Y13 259 has been used for the ras p21, the monoclonal antibody Myc1-9E10 for the c-myc p62 and the polyclonal antibody pAb1 (from Triton Bioscience Inc.) for the c-erbB-2 p185 oncoproteins. The following conclusions can be drawn from the analysis: Of the 100 breast carcinoma cases studied only 14 did not express any of the three oncogenes. The remaining 86 were positive for one or more of the three oncoproteins. Ductal carcinomas expressed oncoproteins in 92% of the cases (67/73), whereas lobular carcinomas expressed them in 70% of the cases (19/27). The most frequently expressed was c-myc p62 in 70% of cases followed by ras p21, 55% and c-erbB-2, 35%. Elevated expression of ras, myc or erbB-2 oncogenes did not correlate with the presence of metastasis in auxiliary lymph nodes, the numbers of infiltrated lymph nodes the grade of the tumor or hormone status. However, there appears to be a correlation between increased ras staining intensity and patient's age, below 50 years.
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PMID:ras, c-myc and c-erbB-2 oncoproteins in human breast cancer. 257 23

The expression of the proteins encoded by the ras, myc, and erb B-2 oncogenes was examined in 63 paraffin-embedded human cholangiocarcinomas of Thai and English origin using immunohistochemistry. The observed distributions were compared with oncogene expression in a series of human hepatocellular carcinomas. In an attempt to relate expression of these three oncogenes to specific stages of normal tissue differentiation, tissue sections of normal fetal, infant, and adult human livers were also examined. Of 63 cholangiocarcinomas, 59 (95%) expressed p62 c-myc, 47 (75%) expressed p21 c-ras, and 46 (73%) expressed p190 c-erbB-2. The expression of c-myc and c-ras but not of c-erb B-2 correlated directly with tumor differentiation as judged by morphologic criteria. No difference was observed in oncogene expression between intrahepatic and extrahepatic cholangiocarcinomas. Twelve of 14 hepatocellular carcinomas (86%) stained positively for all three oncoproteins. During normal liver development, expression of c-myc and c-ras was shown to occur from 18 weeks' gestation until 5 years of age, but not thereafter. Expression of c-myc, c-ras, and c-erbB-2 oncogenes may be used as immunohistochemical markers to distinguish cholangiocarcinoma from nonneoplastic biliary tissues, and may provide useful information concerning the cell biology of tumor differentiation.
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PMID:Oncogene expression in cholangiocarcinoma and in normal hepatic development. 257 40

We studied the overexpression of c-erbB-2 and p21 oncoproteins in human radiation-induced skin ulcers using immunohistochemistry. We found that the positive rate of overexpression of c-erbB-2 and p21 oncoproteins was 92.0 and 92.9%, respectively. The overexpression of c-erbB-2 oncoprotein was observed mainly in the cell membrane of squamous epithelial cells and in the cytoplasm of fibroblasts, endothelial cells, leiomyocytes in the media, and in fibrocytes of the adventitia of mesenchymal arterioles. The location of the p21 oncoprotein overexpression was mostly similar to that of c-erbB-2 with stronger staining in the cytoplasm of squamous epithelial cells and weaker staining in mesenchymal arteriolar walls. The overexpression of c-erbB-2 and p21 oncoproteins may be corresponding to the cancer transformation and poor healing of radiation-induced skin ulcers.
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PMID:Overexpression of c-erbB-2 and p21 oncoproteins in human radiation-induced skin ulcers. 747 70

Several oncogenes and tumour-suppressor genes have been identified that may have an important role in the development of human breast carcinoma. Furthermore, some of these gene alterations may be linked to the development of invasion and subsequent metastasis. Alterations in the expression of ras p21, p53 and c-erbB-2 have all been linked to tumours with rapid cellular proliferation, but the evidence that they are of prognostic importance in patients with breast cancer is conflicting. This study explores the relationship between expression of these oncoproteins and clinical outcome in 92 patients with either locally advanced or metastatic breast cancer treated with primary endocrine therapy. Specimens of the primary carcinoma were available for analysis of hormone receptor, Ki67 labelling index, epidermal growth factor receptor (EGFR), c-erbB-2, p53 and ras p21. Clinical response was measured according to UICC criteria after 6 months of treatment and all patients were followed for time to progression and overall survival. As shown previously, oestrogen receptor (ER) negativity, high Ki67 labelling index and EGFR overexpression were associated with a shorter time to progression and overall survival. However, no statistically significant relationship existed between expression of ras p21, p53 or c-erbB-2 and response to treatment, time to progression or overall survival. We conclude that staining for these three oncoproteins has no role in therapeutic decision-making in patients with advanced breast cancer. The negative finding implies that while abnormal expression of these genes may have an important role in the development of breast cancer, the variations in growth characteristics of advanced breast cancer may be influenced by other factors.
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PMID:Expression of ras p21, p53 and c-erbB-2 in advanced breast cancer and response to first line hormonal therapy. 757 79


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