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

---

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

The aim of this study was to overtake the mechanism of the control system in endometrial cancer cell line in vitro. Ishikawa cell (IK cell) and HEC-1 cell (HEC cell) derived from endometrial cancers were cultured with serum free medium (SFM-101). IK cell possessed Estrogen receptor (ER), Progesterone receptor (PR), Epidermal growth factor (EGF) and its receptor (EGFR). HEC cell had PR, EGF, and EGFR, however HEC cell did not keep ER. EGF stimulated the growth of IK cell, but the growth of HEC cell was not stimulated by EGF. S phase cells were increased by EGF in IK cell, but were not increased by EGF in HEC cell. The growth of IK cell was stimulated significantly by EGF and Estradiol-17 beta (E2) +EGF than control. However, E2+EGF did not stimulate the growth of IK cell than EGF significantly. Danazol (D) and D+EGF inhibited the growth of IK cell significantly than control. S phase cells were decreased by the treatment of D and D+EGF. From our results, EGF stimulated the growth of ER positive endometrial cancer cell, but EGF did not stimulate ER negative endometrial cancer cell. E2+EGF and EGF stimulated the growth of IK cell as a same. However, D inhibited the growth of IK cell that was stimulated by EGF.
...
PMID:[Cell cycle analysis of endometrial cancer cells in vitro treated with growth factor and steroid hormone]. 130

In order to evaluate the incidence and prognostic significance of gene amplification in primary brain neoplasms we measured the number of gene copies per cell of three oncogenes (epidermal growth factor receptor [EGFR] gene, N-myc, C-myc) and syntenic control genes in 40 specimens using quantitative DNA dot blots. We observed EGFR gene amplification in astrocytomas and anaplastic astrocytomas with approximately the same incidence as in glioblastoma multiforme (33%), although large amplifications were only seen in glioblastoma multiforme. Fourteen patients had a supratentorial glioblastoma multiforme; six had EGFR gene amplification and eight had either normal EGFR gene copy number or elevated EGFR copy number attributable to extra copies of chromosome 7. Patients with gene amplification had shorter survival than patients without gene amplification (p = 0.01). The observed difference in survival was not likely to be due to group differences in age, sex, treatment, or histopathology.
...
PMID:Amplification of epidermal growth factor receptor gene in gliomas: histopathology and prognosis. 131 Oct 22

Clonal cytogenetic abnormalities found in 30 non-small cell lung carcinomas (NSCLC), including 28 newly diagnosed primary tumor specimens, are summarized. Multiple chromosome alterations were identified in every case, and 19 of 30 tumors had near-triploid or near-tetraploid karyotypes. Polysomy 7 and partial gains of 7p, including 7p11-p13 (site of the EGFR gene), were particularly frequent, occurring alone or in combination in 26 tumors. Recurrent losses involving 1p, 3p, 6q, 9p, 11p, 15p, and 17p (where the TP53 gene is located) were each seen in 16-25 cases. Five tumors exhibited double minutes, which were associated with amplified MYC1 (1 case) and EGFR (1 case), as determined by Southern analysis. The cytogenetic data were compiled from either short term cultures of tumor tissue harvested within 1-9 days (18 cases) or later harvests performed on long term cultures or cell lines (6 cases); in the other 6 cases results were obtained from both short term and long term cultures. Two studies were performed to validate the use of long term culture for cytogenetic analysis of solid lung tumors. First, in order to determine whether cytogenetic results from cultures are representative of the original tumor, the modal chromosome number of 13 specimens placed into culture was compared to the DNA index of the original tumor tissue, as measured by flow cytometry. The DNA indices of the solid tumor biopsies agreed with the degree of aneuploidy observed by cytogenetic analysis in every case. Second, in 6 cases we performed direct comparisons of karyotypes obtained from cells cultured by both methods. Identical chromosome abnormalities were detected in short term cultures and later harvests of the same specimen. Overall, our findings indicate that tumorigenesis in NSCLC is characterized by the accumulation of multiple chromosome alterations. Furthermore, these data demonstrate that recurrent cytogenetic changes can be identified in NSCLC and that detailed karyotypes from long term cultures are relevant to the original tumor. Chromosome abnormalities detected by these techniques may have clinical and biological significance. However, the complex pattern of karyotypic changes seen in newly diagnosed NSCLC emphasizes the need for future investigations of premalignant bronchial lesions in order to identify primary genetic changes important for early detection and intervention in this aggressive neoplasm.
...
PMID:Chromosome abnormalities in human non-small cell lung cancer. 131 34

We have compared the protein tyrosine kinase activities of the chicken epidermal growth factor receptor (chEGFR) and three ErbB proteins to learn whether cancer-activating mutations affect the kinetics of kinase activity. In immune complex assays performed in the presence of 15 mM Mn2+, ErbB proteins and the chEGFR exhibited highly reproducible tyrosine kinase activity. Under these conditions, the ErbB and chEGFR proteins had similar apparent Km [Km(app)] values for ATP. The ErbB proteins appeared to be activated, as they had at least 3-fold-higher relative Vmax(app) for autophosphorylation and approximately 2-fold higher relative Vmax(app) for the phosphorylation of the exogenous substrate TK6 (a bacterially expressed fusion protein containing the C-terminal domain of the human EGFR). The ErbB kinases had both higher Km(app) and higher Vmax(app) for the phosphorylation of the exogenous substrate TK6 than did the chEGFR. The ratios of the Vmax(app) to the Km(app) for TK6 phosphorylation suggested that the ErbB proteins had lower catalytic efficiencies for the exogenous substrate than did the chEGFR. The three tested ErbB proteins had cytoplasmic domain mutations that conferred distinctive disease potentials. These mutations did not affect the kinetics for the phosphorylation of the exogenous substrate TK6. Two of the ErbB proteins contained all of the sites used for autophosphorylation. In these, a mutation that broadened oncogenic potential to endothelial cells caused an additional increase in Vmax(app) for autophosphorylation. Thus, mutations that change the EGFR into an ErbB oncogene cause multiple changes in the kinetics of protein tyrosine kinase activity.
...
PMID:Protein tyrosine kinase activities of the epidermal growth factor receptor and ErbB proteins: correlation of oncogenic activation with altered kinetics. 131 48

To document over-expression of proto-oncogenes in tumors, it is necessary to determine the level of expression in the progenitor normal tissue. These studies compare the levels of nuclear transcription of a series of growth-factor related genes and proto-oncogenes in human glioblastoma cell lines with those in three normal glial cell populations. The unusual finding was that levels in the three normal glial cell populations varied considerably for several genes and thus overexpression of a specific gene in a tumor cell when compared to just one normal glial cell population would not necessarily represent overexpression. In this study, we compared the level of 17 genes in 7 tumors to the highest level of each gene found in any of three normal glial cell populations. Over-expression of PDGF-B in 4/7 glioblastoma cell lines, EGFR in 1/7, neu in 1/7 IGF-2 in 1/7 and ros in 2/7 was observed. The variation observed in the normal glial cell populations emphasizes the possibility that the normal glial cell populations represent different glial cell lineages and/or stages of differentiation and that the tumors could have arisen from different normal glial cells. Matching lineages of normal and tumor cells, probably by monoclonal antibody reactions, may be required to accurately define over-expression.
...
PMID:Transcriptional patterns of growth factors and proto-oncogenes in human glioblastomas and normal glial cells. 132 85

The tyrosine kinase activity of the epidermal growth factor receptor (EGFR-TK) was determined at varying poly-Glu6Ala3Tyr1 (GAT) or [Val5]-angiotensin II (AT) and constant ATP concentrations and vice versa. With GAT as substrate, double reciprocal plots intersected practically on the abscissa following EGFR-TK pre-activation with EGF, but below the abscissa without EGF pre-activation. The EGFR-TK inhibitors App(NH)p (5'-adenylyl-beta, gamma-imidodiphosphate) and ADP were competitive with ATP and noncompetitive with GAT. Four families of 1/v vs. 1/[ATP] plots, constructed at different fixed concentrations of ADP and a different constant concentration of GAT for each family, yielded Slope1/ATP replots which intersected to the left of the ordinate and below the abscissa. GAT and AT, as cosubstrates, were competitive with each other and noncompetitive with ATP; 1/v vs. 1/[GAT] or 1/[AT] plots were hyperbolic and reached horizontal asymptotes when v was expressed as the rate of common product formation. All data were subjected to computer best-fit analysis by a program written especially for this purpose. We conclude that (i) the EGFR-TK reaction follows a Sequential Bi-Bi Rapid Equilibrium Random mechanism, and (ii) EGF induces conformational changes in the EGFR-TK active center which lead to marked decreases in the apparent dissociation constants of both substrates of the kinase reaction and a concomitant increase in initial velocities and Vmax (apparent).
...
PMID:Kinetic model of the epidermal growth factor (EGF) receptor tyrosine kinase and a possible mechanism of its activation by EGF. 132 5

The expression of oncogene products related to cell growth (c-erbB-2, c-myc, ras p21, EGFR) was investigated in benign (15 cases) and malignant breast lesions (20 cases) by means of immunohistochemistry using the avidin-biotin-peroxidase technique with polyclonal and monoclonal antibodies. The aim of this study was to evaluate the relationship between the staining positivity and various morphological and biological features, such as tumour type, grading, hormone receptor status and cell kinetic parameters. In benign breast lesions, as expected, the kinetic parameters were low, both for Ki-67 and LI. All the specimens showed a diploid condition (the DI being equal to 1) and we found a limited degree of immunoreactivity for all the growth factors and oncogene products. In breast cancer we studied the distribution of immunohistochemical positivity for EGFR, c-erbB-2, c-myc, ras p21 and Ki-67, which was related to age, nodal status, ER and PgR receptor status, LI, DI and histopathological grading. A significant positive correlation was found both between ras p21 expression and nodal status and ER-ICA positivity. We observed a strong correlation between LI and Ki-67 and an inverse relation between Ki-67 and ER expression. These findings suggest the importance of studying the relationship between prognostic factors which may provide preoperative prediction in the biological behaviour of breast cancer, not only on biopsy specimens, but also on fine needle aspirates.
...
PMID:Preliminary study on oncogene product immunohistochemistry (c-erbB-2, c-myc, ras p21, EGFR) in breast pathology. 134 7

Autophosphorylation of gp185erbB-2 in vivo is confined to its carboxy terminus and is required for optimal erbB-2 transforming activity under conditions of receptor overexpression. It remains unresolved, however, to what extent autophosphorylation regulates erbB-2 mitogenic signaling in normal cells, nor is the biochemical basis for such a regulatory function known. To address these issues, we utilized a chimeric molecule encompassing the extracellular domain of the epidermal growth factor (EGF) receptor (EGFR) fused to the transmembrane and intracellular domains of the erbB-2 product. In this EGFR/erbB-2 chimera, erbB-2 kinase activity is regulated by EGF binding. An EGFR/erbB-2 mutant bearing multiple Tyr----Phe substitutions at erbB-2 autophosphorylation sites (EGFR/erbB-2 5P) displayed markedly reduced phosphotyrosine content following EGF stimulation in comparison with the non-mutated chimera. When expressed in NR6 cells, the EGFR/erbB-2 5P mutant was unable to deliver a sizeable mitogenic signal when activated by EGF at physiological levels. In intact cells, the 5P mutant was still able to stimulate phosphorylation of the gamma isozyme of phospholipase C (PLC-gamma), a prototype erbB-2 substrate, although with a delayed time course, indicating that the 5P mutation decreased the affinity of the erbB-2 kinase for this substrate. This conclusion was further supported by the inability of the 5P mutant to associate with PLC-gamma in co-immunoprecipitation experiments. We infer that a major role of autophosphorylation is to increase the affinity of the erbB-2 kinase for its cellular substrates, so that, under physiological conditions, autophosphorylation is absolutely required for erbB-2 mitogenic signaling.
...
PMID:erbB-2 autophosphorylation is required for mitogenic action and high-affinity substrate coupling. 135 97

As the factor binding to the neu protein has been unknown, it has not been possible to confirm experimentally the proposed growth-factor receptor like functions of the neu protein. To approach this problem we constructed a recombinant receptor which enabled ligand regulation of the neu tyrosine kinase. The hybrid receptor consisted of the extracellular ligand binding, transmembrane and protein kinase C-substrate domains joined to the intracellular tyrosine kinase and carboxyl-terminal domains of the neu protein. Several properties of NIH3T3 cells carrying this construct were tested. We obtained the first experimental evidence that the neu proto-oncogene has mitogenic and transforming activities only in the presence of a ligand stimulating its tyrosine kinase activity. Various cellular and molecular biological parameters indicated that the chimeric receptor behaved very similarly to the EGFR. Also, this chimeric receptor has allowed us to compare the constitutive oncogenic and the ligand-activated non-oncogenic activities of the neu tyrosine kinase. In the future we plan to focus on characterization of possible differences between EGFR and neu signalling in more differentiated cellular backgrounds.
...
PMID:A chimeric EGFR/neu receptor in functional analysis of the neu oncoprotein. 135 54

The epidermal growth factor (EGF) receptor (EGFR) and the erbB-2 gene product, gp185erbB-2, exhibit distinct abilities to stimulate mitogenesis in different target cells. By using chimeric molecules between these two receptors, we have previously shown that their intracellular juxtamembrane regions are responsible for this specificity. Here we describe a genetically engineered EGFR mutant containing a threonine for arginine substitution at position 662 in the EGFR juxtamembrane domain, corresponding to threonine 694 in gp185erbB-2. This mutant, designated EGFRThr662, displayed affinity for EGF binding and catalytic properties that were indistinguishable from those of the wild type EGFR. However, EGFRThr662 behaved much as gp185erbB-2 in a number of bioassays which readily distinguish between the mitogenic effects of EGFR and gp185erbB-2. Moreover, significant differences were detected in the pattern of intracellular proteins phosphorylated on tyrosine in vivo by EGFR and EGFRThr662 in response to EGF. Thus, small differences in the primary sequence of two closely related receptors have dramatic effects on their ability to couple with mitogenic pathways.
...
PMID:A single amino acid substitution is sufficient to modify the mitogenic properties of the epidermal growth factor receptor to resemble that of gp185erbB-2. 135 64


1 2 3 4 5 6 7 8 9 10 Next >>

---