Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the expression of c-H-ras (p21), c-erb B1 (EGFR) and c-erb B2 (p185) gene products in human bladder cancer, immunohistochemical studies using monoclonal antibodies to these proteins were performed on formaline fixed (within 15 hours)-paraffin sections of tumor tissues from 20 patients with bladder cancer, normal appearing adjacent bladder (non-tumor) tissues from 11 of the 20 patients, and normal bladder tissues from 3 patients who died of non-cancerous diseases as control. p21 Positive staining was demonstrated in the superficial cells of urothelium in 1 of 3 controls, also in 5 of 20 tumor tissues compact cells without vacuole in cells which have an increased nuclear/cytoplasmic ratio. Seven of 11 non-tumor tissues indicated positive staining either in superficial layer only or in whole layers of urothelium, and 1 of the latter group reacted with the monoclonal antibody to human bladder cancer produced in our laboratory. EGFR was found in 5 of 20 tumor tissues and 7 of 11 non-tumor tissues, but not in controls. Most EGFR positive tissues also indicated p21 positivity except in 1 of the tumor tissues. p185 Positive staining was demonstrated in 9 of 20 tumor tissues and 5 of 11 non-tumor tissues, but not in the controls. Furthermore, 5 of 6 tumor tissues from the patients with lymph node metastasis indicated p185 positivity. These results suggest that both p21 and EGFR may have a role in transformation and that p185 has a role in the development of metastasis in some urothelial malignancies.
 ...
PMID:[Expression of c-H-ras, c-erb B1 and c-erb B2 gene products in human bladder cancer]. 135 18

In order to obtain further information on the biological role of the HER2/neu oncoprotein monoclonal antibodies (MAbs) were produced against the p185 extracellular domain. To immunize the mice and screen the hybridoma supernatants we selected a lung adenocarcinoma cell line (Calu-3), which demonstrated an over-expression of p185HER2 measured as the reactivity with polyclonal rabbit serum to the 14-amino-acid carboxy-terminal-HER2/neu. Two MAbs, designated MGR2 (IgG1) and MGR3 (IgG2), selected for reactivity on Calu-3 and negativity on A43I live cells, the reference target cell for EGF receptor expression, were found to immunoprecipitate a 185-kDa molecule. Immunodepletion experiments with the polyclonal antiserum and cross-competition experiments indicated that the 2 reagents recognized 2 different epitopes located on the p185HER2 molecule. One of the 2 MAbs, MGR3, was found to internalize, induce p185HER2 phosphorylation and inhibit tumor cell growth in vitro. These results indicate that MGR3 is directed against a determinant located in the p185HER2 ligand binding site and may compete with the p185HER2 ligand, but is incapable of inducing a complete mitotic signal.
 ...
PMID:Selection of monoclonal antibodies which induce internalization and phosphorylation of p185HER2 and growth inhibition of cells with HER2/NEU gene amplification. 167 68

Epidermal growth factor (EGF) and EGF-related growth factors are present in the urine, and EGF has been identified as a urinary component that enhances urinary bladder tumor formation in rats. Neu oncogene encodes a cell surface receptor similar to the EGF receptor and is known to be activated by a point mutation of DNA that encodes the transmembrane domain of the neu protein (p185). In this study, we examined the possible mutational activation of neu oncogene in 50 urinary bladder transitional cell carcinomas (TCC) induced in F344 rats by the following carcinogenesis models: (i) 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) (4 weeks)----3% uracil (20 weeks); (ii) 0.2% N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) (6 weeks)----5% sodium saccharin (72 weeks); and (iii) N-methyl-N-nitrosourea (MNU) 20 mg/kg body wt, i.p. twice per week for 4 weeks----3% uracil (20 weeks). The DNA sequence around the transmembrane domain of neu gene was amplified by PCR and sequenced. The results showed no mutation within the examined DNA sequences, indicating that neu oncogene is not activated by a point mutation in the transmembrane domain in urinary bladder carcinomas induced by BBN, FANFT or MNU.
 ...
PMID:Direct DNA sequencing of the rat neu oncogene transmembrane domain reveals no mutation in urinary bladder carcinomas induced by N-butyl-N-(4-hydroxybutyl)nitrosamine, N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide or N-methyl-N-nitrosourea. 168 63

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.
 ...
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.
 ...
PMID:Modulation of a Mr 175,000 c-neu receptor isoform in G8/DHFR cells by serum starvation. 197 80

The Mr 185,000 glycoprotein encoded by human c-erbB-2/neu/HER2 gene, termed c-erbB-2 gene product, shows a close structural similarity with epidermal growth factor receptor and is now regarded to be a growth factor receptor for an as yet unidentified ligand. Abundant c-erbB-2 mRNA was demonstrated by Northern blot studies in the human breast cancer cell line SK-BR-3. Cellular radiolabeling experiments followed by immunoprecipitation with three different anti-c-erbB-2 gene product antibodies, recognizing extracellular domain, kinase domain, and carboxyl-terminal portion, respectively, demonstrated the production of a large amount of c-erbB-2 gene product which had the capacity to be phosphorylated. Immunization of mice with concentrated culture medium conditioned by SK-BR-3 cells always generated antibodies against c-erbB-2 gene product, demonstrating that this culture medium contained substance(s) immunologically indistinguishable from c-erbB-2 gene product. This observation was supported by the successful development of a monoclonal antibody against c-erbB-2 gene product, GFD-OA-p185-1, by immunizing mice with this culture medium. The biochemical nature of the substance(s) present in the culture medium was further characterized. When the culture medium conditioned by [35S]cysteine-labeled SK-BR-3 cells was immunoprecipitated by three different anti-c-erbB-2 gene product antibodies, only the antibody recognizing extracellular domain precipitated the [35S]-labeled protein with a molecular weight of 110,000, namely p110. The newly developed monoclonal antibody also immunoprecipitated this protein.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The presence of c-erbB-2 gene product-related protein in culture medium conditioned by breast cancer cell line SK-BR-3. 198 Nov 43

The rat neu oncogene encodes a cell surface glycoprotein, p185, that possesses tyrosine kinase activity. The p185 polypeptide exhibits structural similarity to the epidermal growth factor receptor (EGFR) at both the deduced amino acid and nucleic acid level. However, the neu oncogene and the gene encoding the EGFR have been shown to reside on distinct chromosomes. Comparative analysis of the sequences of the normal neu cDNA and of the neu cDNA from neuroblastomas has revealed a single point mutation leading to a valine-to-glutamic acid substitution in the transmembrane anchoring domain. This mutation converts the neu gene to a transforming gene in rodents. In humans, the gene is called ERBB2 (also NGL and HER2), and amplification and over-expression of its products have been detected in certain tumors. The rat embryonal fibroblast cell line (Rat-1) appears to express both EGFR and cellular p185 polypeptides. We have found that EGF stimulates the phosphorylation of p185 in these cells at tyrosine as well as serine and threonine residues in a specific and dose-dependent manner. This activity occurs even though radiolabeled EGF cannot bind to immunopurified p185. The EGF effect is apparently unique since platelet-derived growth factor, insulin, and transforming growth factor beta all fail to phosphorylate p185 at tyrosine. The EGF-induced effect requires interaction of the EGFR and its cognate ligand because cell lines that lack EGFR cannot be shown to phosphorylate p185, even when exposed to large amounts of EGF. Oncogenic rodent p185 and the human p185 homologue ERBB2 that is overexpressed in human breast tumor cells also can be shown to become phosphorylated on tyrosine residues by the action of EGF. Collectively, these data demonstrate that EGF mediates phosphorylation of p185 at tyrosine as well as serine/threonine through cellular kinases by a receptor-specific mechanism.
 ...
PMID:Phosphorylation process induced by epidermal growth factor alters the oncogenic and cellular neu (NGL) gene products. 289 89

The neu oncogene (also referred to as c-erbB-2 and HER2) encodes a 185-kDa transmembrane glycoprotein with tyrosine kinase activity termed p185. The p185 glycoprotein is structurally related to the epidermal growth factor receptor. It is thought that p185 is the receptor for an as yet unidentified growth factor. In the present study, RNA blot analyses and immunohistochemical studies were performed on rat tissues obtained from a variety of prenatal and postnatal stages to examine the expression of the neu oncogene and its product, p185, during normal development. Expression of the neu gene was detected in mid-gestation embryos in a variety of tissues including nervous system, connective tissue, and secretory epithelium, but not in lymphoid tissue. In adult animals, secretory epithelial tissues and basal cells of the skin expressed neu. These studies demonstrate that the neu gene is expressed in a tissue- and developmental stage-specific manner. We suggest that the p185 molecule plays an important role in the growth and development of a variety of tissues, and, in particular, in epithelial tissue.
 ...
PMID:Stage- and tissue-specific expression of the neu oncogene in rat development. 331 11

The retinoid N-(hydroxyphenyl) retinamide (4-HPR) appears to be a promising tool for chemoprevention of breast carcinoma, and clinical trials to evaluate its effect are in progress. However, its action on tumor cells has remained largely undefined. We report here that 4-HPR induced apoptosis and/or differentiation in breast cancer cell lines, independent of hormone receptor status and retinoic acid receptor expression, although it was slightly more efficient in inhibiting proliferation of estrogen receptor-positive cells. 4-HPR up-modulated expression of several differentiation markers (class 1 HLA, laminin, and beta 1 integrin chain) and down-regulated expression of molecules associated with tumor progression, including the p185/HER2 oncoprotein, the epidermal growth factor receptor, and the M(r) 67,000 laminin receptor. These data suggest that 4-HPR could exert a beneficial effect by inhibiting cell proliferation and modulating breast tumor aggressiveness.
 ...
PMID:Modulation of markers associated with tumor aggressiveness in human breast cancer cell lines by N-(4-hydroxyphenyl) retinamide. 754 8

Activation of the ERBB2 oncogene seems to be an early event in breast cancer progression and prevalent in in situ carcinomas. However, its prognosis value, albeit recognized for node-positive patients, remains controversial for those without apparent nodal involvement. One possible reason for this problem is likely to be the difficulty of defining threshold levels for ERBB2 protein overexpression. ERBB2 protein expression was therefore analyzed in primary invasive breast tumors. Quantification of the gene product by a commercial ELISA test was compared to results obtained by immunohistochemistry and western blotting, as well as to gene amplification status determined by Southern blotting. Correlations between results obtained by the different techniques were highly significant (P value < 10(-6)). Nevertheless, ELISA permitted us to determine three levels of protein expression corresponding to distinct tumor subsets. 1) Tumors with p185/ERBB2 expression levels exceeding 10 U/microgram exhibited in most cases amplification of the gene (83% of cases), DNA aneuploidy (81%) and absence of estrogen receptor (ER) (44%). Such high levels of protein expression were exclusively observed in invasive ductal carcinomas and were prevalent in those showing a significant in situ component. 2) "Intermediate" levels of expression (3-10 U/micrograms) were rarely observed in tumors exhibiting gene amplification (9%), but were preferentially found in cancers of more favorable prognosis (only 49% were aneuploid and 9% estrogen receptor negative). 3) Levels of p185/ERBB2 below 3 U/micrograms were detected in benign mastopathies and, thus, carcinomas presenting such levels were scored ERBB2 negative. Interestingly, invasive lobular carcinomas were rarely ERBB2 positive, and if so, only at intermediate levels. Moreover, our data show a complex interrelationship between p185/ERBB2 expression and ER levels. Indeed, tumors with more than 10 U/micrograms of p185 were prevalently ER, whereas those with p185 ranging from 3 to 10 U presented elevated levels of ER.
 ...
PMID:Quantification of ERBB2 protein expression in breast cancer: three levels of expression defined by their clinico-pathological correlations. 784 39


1 2 3 4 5 6 7 8 Next >>