Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously isolated a Fisher rat fibroblast mutant, B812, that has the unique property of temperature-dependent transformation by various oncogenic retroviruses. At the permissive temperature (35 degrees C), this mutant was sensitive to oncogenic transformation and formed foci on a dish at the same frequency as did the parental fibroblast cell line. When Kirsten murine sarcoma virus (Ki-MSV) was applied to the cells, the frequency of focus formation decreased more than 25-fold at the nonpermissive temperature (39 degrees C), whereas the cells expressed nearly the same level of the ras transcript as well as the ras protein. The temperature-restricted focus formation was fully reversible and was completely suppressed upon fusion with the wild-type parent cell. In addition to ras, the mos, fos, src, and erbB-2 oncogenes transformed this mutant with the same temperature dependence as described above; polyomavirus middle T antigen, adenovirus type 12, and human papillomavirus 16-E67 also transformed, but without temperature dependence. These results suggest that ras, fos, mos, src, and erbB-2 use a common cellular pathway for transforming cells.
Mol Cell Biol 1989 Dec
PMID:A cell mutant that exhibits temperature-dependent sensitivity to transformation by various oncogenes. 247 32

Transforming growth factor-alpha (TGF-alpha) is a growth-promoting protein that binds to the epidermal growth factor (EGF) receptor. To identify critical residues that govern TGF-alpha-EGF receptor binding, we prepared site-specific substitution mutants of TGF-alpha. Mutant proteins were tested in receptor-binding and mitogenesis assays. Semiconservative substitutions at positions 4, 12, 18, and 45 decreased biological activity 2.1- to 14-fold. The conservative substitution of lysine for arginine at position 42 completely eliminated biological activity. Amino acid composition analysis of proteolytic fragments from TGF-alpha and the Lys-42 mutant indicated that these proteins contained the same disulfide bonds. These studies suggest that arginine 42 may be a contact point for TGF-alpha-EGF receptor interaction.
Mol Cell Biol 1989 Sep
PMID:Substitution of lysine for arginine at position 42 of human transforming growth factor-alpha eliminates biological activity without changing internal disulfide bonds. 250 41

The expression of hepatic epidermal growth factor (EGF) receptor gene was studied in genetically diabetic (C57BL/KsJ db/db) mice and streptozotocin-induced diabetic mice. The binding of 125I-labelled EGF to hepatic membrane preparations of genetically diabetic mice was only 35% of that of non-diabetic mice. Levels of EGF receptor messenger RNAs (10 and 6 kb) in the liver of the diabetic animals were also reduced by about 75%. In streptozotocin-induced diabetic mice, levels of hepatic EGF binding and messenger RNAs for EGF receptor were decreased to 27 and 30% of control levels respectively, at 5 weeks after injection of the drug. There were, however, no significant differences in levels of messenger RNAs for the structural protein beta-actin in the liver. In addition, levels of EGF receptor messenger RNAs in the kidney were similar between control and the two kinds of diabetic mice. Daily administration of insulin to the streptozotocin-induced diabetic mice increased the hepatic levels of EGF receptor messenger RNAs to almost normal levels. These results indicate that EGF binding to its receptor decreases in the liver of diabetic mice, involving alterations in the level of EGF receptor messenger RNAs, and that insulin is important for the regulation of EGF receptor gene expression in the liver but not in the kidney.
J Mol Endocrinol 1989 Jul
PMID:Decreased expression of hepatic epidermal growth factor receptor gene in diabetic mice. 252 15

Synthesis and metabolism of the epidermal growth factor (EGF) receptor are extensively regulated to modulate cellular responses to ligand. To study regulation of EGF receptor gene expression, the 5' region of the gene was isolated from a human placental genomic library. A 5' proximal 1.1-kilobase fragment (-1100 to -19 relative to the ATG translation start site) and subfragments of this were subcloned in both forward and reverse orientations into the luciferase expression vector pSVOAL delta 5' and transfected into human cell lines. Luciferase activity was stimulated by treatment of transfected HeLa cells with EGF, 12-O-tetradecanoylphorbol 13-acetate (TPA), (Bu)2 cAMP, retinoic acid, and dexamethasone. Deletion analysis indicated full retention of activity after removal of the -1100 to -485 region (-485 to -19 fragment), but a 5-fold reduction in activity on removal of the -485 to -153 region (-153 to -19 fragment). Despite a reduction in basal activity, the proximal 134-basepair fragment retained responses to all inducers. Additivity was observed in response to maximal concentrations of TPA plus retinoic acid and of TPA plus (Bu)2 cAMP; the response to a combination of four inducers exceeded that to the RSV-LTR strong promoter. Differences in stimulated responses were observed in various recipients, with hepatoma HepG2 cells lacking responses to (Bu)2 cAMP and glioblastoma T98G cells lacking responses to EGF and TPA. These results indicate that a 134-basepair DNA fragment closely adjacent to the translation start site contains elements responsible for directing basal and stimulated expression of the EGF receptor gene.
Mol Endocrinol 1989 Feb
PMID:Regulation of epidermal growth factor receptor gene expression. 254 Apr 31

The HER2/c-erbB-2 gene encodes the epidermal growth factor receptorlike human homolog of the rat neu oncogene. Amplification of this gene in primary breast carcinomas has been show to correlate with poor clinical prognosis for certain cancer patients. We show here that a monoclonal antibody directed against the extracellular domain of p185HER2 specifically inhibits the growth of breast tumor-derived cell lines overexpressing the HER2/c-erbB-2 gene product and prevents HER2/c-erbB-2-transformed NIH 3T3 cells from forming colonies in soft agar. Furthermore, resistance to the cytotoxic effect of tumor necrosis factor alpha, which has been shown to be a consequence of HER2/c-erbB-2 overexpression, is significantly reduced in the presence of this antibody.
Mol Cell Biol 1989 Mar
PMID:p185HER2 monoclonal antibody has antiproliferative effects in vitro and sensitizes human breast tumor cells to tumor necrosis factor. 256 7

DNAs from 37 human gastric carcinomas and seven lymph node metastases were analyzed for alterations of the epidermal growth factor receptor (EGFR) gene and oncogenes by the Southern blot hybridization method. The probes used were EGFR gene, c-Ha-ras, v-Ki-ras, N-ras, c-myc, v-myb, v-fos, c-erbB-2, v-erbA, v-abl and v-fes. Amplification of the EGFR gene was detected in only one poorly differentiated adenocarcinoma. Amplifications of c-myc gene and c-erbB-2 gene were each observed in two well differentiated adenocarcinomas. One of these tumors had coamplification of c-erbB-2 and c-erbA genes but there were no amplifications nor rearrangements of other oncogenes. The poorly differentiated adenocarcinom with amplified EGFR gene also showed enhanced expression of EGFR gene by Northern blot analysis and additionally had strong synchronous immunoreactivity for EGFR and EGF.
Virchows Arch B Cell Pathol Incl Mol Pathol 1989
PMID:Amplification of epidermal growth factor receptor (EGFR) gene and oncogenes in human gastric carcinomas. 257 Apr 89

The response of malignant and nonmalignant human breast cell lines to the growth inhibitory effects of monoclonal antibodies against the epidermal growth factor (EGF) receptor was studied. A series of human breast cell lines, which express EGF receptor, were used: MDA-468, MDA-231, and Hs578T human breast cancer cells and the transformed human mammary epithelial cell lines 184A1N4 and 184A1N4-T that have been benzo[a]pyrene immortalized and further transformed with SV40T, respectively. Four antibodies of two different classes were tested: 225 immunoglobulin G (IgG), 108.4 IgG, 96 immunoglobulin M (IgM), and 42 IgM. All four antibodies inhibited the anchorage-dependent and -independent, EGF-stimulated growth of 184A1N4 and 184A1N4-T cells, respectively, and this growth inhibition could be reversed by the addition of increasing concentrations of EGF. In contrast, the antibodies inhibited the anchorage-dependent and -independent growth of MDA-468 cells in the absence of exogenous EGF suggesting that the antibodies were acting to block access of an endogenously produced ligand to the EGF receptor. In the presence of antibody and increasing concentrations of EGF, MDA-468 cell growth was first stimulated then inhibited as the EGF concentration increased, thus, uncovering the growth stimulatory potential of low concentrations of EGF in these cells. Data is presented that indicates MDA-468 cells secrete a transforming growth factor with autocrine growth stimulatory capabilities. The growth of MDA-231 and Hs578T cells, which contain activated ras oncogenes, was not inhibited by the antibodies and the growth of these cell lines was not stimulated by EGF. Of the cell lines studied only MDA-468 cells appear to possess an autocrine growth stimulatory capacity.
Mol Endocrinol 1989 Nov
PMID:Anti-epidermal growth factor receptor antibodies inhibit the autocrine-stimulated growth of MDA-468 human breast cancer cells. 260 59

Considerable advances have been made in our understanding of cell growth regulation in mammalian cells. In particular, studies on transformed and normal cells have highlighted the contribution of growth factor-related control mechanisms in cell growth regulation. We set out to investigate whether host growth factors are involved in the growth regulation of the parasitic protozoan Trypanosoma brucei. We demonstrate that antibodies to the mammalian epidermal growth factor (EGF) receptor bind to the trypanosome T. brucei and, that these antibodies recognise a surface polypeptide of 135 kDa. This polypeptide is one of only two polypeptides in parasite extracts that bind EGF. Furthermore, EGF modifies protein kinase activity and growth rate of trypanosomes in vitro. These results lead to the conclusion that T. brucei has a surface growth factor receptor with considerable homology to the EGF receptor, and raise the possibility that growth factor interactions similar to those found in mammalian cells are involved in cell growth regulation in trypanosomes.
Mol Biochem Parasitol 1989 Aug
PMID:Identification of an epidermal growth factor receptor homologue in trypanosomes. 268 37

The tyrosine kinase activity of the epidermal growth factor (EGF) receptor is regulated by a truncated receptor of 100 kilodaltons (kDa) that contains the EGF-binding site but not the kinase domain. The inhibition of kinase is not due to competition for available EGF or for the kinase substrate-binding site. Chemical cross-linking studies suggest that the 100-kDa receptor may form a heterodimer with the intact EGF receptor. Structurally related receptor kinases, such as the platelet-derived growth factor receptor, the insulin receptor, and the Neu receptor, were not inhibited by the 100-kDa receptor. The results indicate that (i) the inhibition was specific for the EGF receptor, (ii) the kinase domain had little or no role in determining target specificity, and (iii) the regulation of kinase may be due to a specific interaction of the 100-kDa receptor with the ligand-binding domain of the EGF receptor kinase.
Mol Cell Biol 1989 Feb
PMID:Inhibition of tyrosine kinase activity of the epidermal growth factor (EGF) receptor by a truncated receptor form that binds to EGF: role for interreceptor interaction in kinase regulation. 278 40

Previous reports have indicated that the C termini of the membrane-associated tyrosine kinases encoded by c-src and c-fms proto-oncogenes have a negative effect on their biological activity and that this effect is mediated by their C-terminal tyrosine residue. To determine whether this was true for the human epidermal growth factor (EGF) receptor, which is also a membrane-associated tyrosine kinase proto-oncogene, we have constructed two premature termination mutants, dc19 and dc63, that delete the C-terminal 19 and 63 amino acids, respectively, from the human full-length receptor (hEGFR). The smaller deletion removes the C-terminal tyrosine residue, while the larger deletion removes the two most C-terminal tyrosines; similar deletions are found in v-erbB. As previously shown for the gene encoding the full-length EGF receptor, the two C-terminal mutants induced EGF-dependent focal transformation and anchorage-independent growth of NIH 3T3 cells. However, both dc19 and dc63 were quantitatively less efficient than the gene encoding the full-length receptor, with dc63 being less active than dc19. Although the C-terminal mutants displayed lower biological activity than the gene encoding the full-length receptor, the mutant receptors were found to be similar in several respects to the full-length receptor. These parameters included receptor localization, stability in the absence of EGF, receptor half-life in the presence of EGF, EGF binding, extent of EGF-dependent autophosphorylation in vitro, and EGF-dependent phosphorylation of an exogenous substrate in vitro. Therefore, the C-terminal 63 amino acids of the human receptor have no detectable influence on EGF-dependent early events. We conclude that in contrast
Mol Cell Biol 1989 Apr
PMID:Functional heterogeneity of proto-oncogene tyrosine kinases: the C terminus of the human epidermal growth factor receptor facilitates cell proliferation. 278 42


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