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

GM-CSF is a cytokine with pleiotropic biological activities and is increasingly used in clinical trials. The present study demonstrates the ability of recombinant human granulocyte-macrophage colony-stimulating factor (rGM-CSF) to induce elevation of interleukin-10 (IL-10) mRNA and protein production in the monocytic cell line U937. As shown by a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), IL-10 mRNA increases up to 10 times when stimulated with rGM-CSF (100 U/ml) compared to nonstimulated control cells. Maximal IL-10 mRNA expression occurs at 6 h and remains high for 2 h. Thereafter IL-10 mRNA is downregulated and reaches basal level at approximately 24 h. IL-10 protein was measured by ELISA. The protein yield is dose-dependent on the rGM-CSF concentration. Combined stimulation of U937 cells with both GM-CSF and TNF-alpha results in an additive elevation of the IL-10 protein yield. Application of a neutralising antibody against TNF-alpha revealed that GM-CSF induces IL-10 expression independently from TNF-alpha. By using a luciferase reporter gene it was shown that rGM-CSF enhances IL-10 promoter activity 2-3-fold in a transient transfection assay.
Mol Immunol 1998 Jun
PMID:Recombinant human granulocyte-macrophage colony-stimulating factor triggers interleukin-10 expression in the monocytic cell line U937. 979 52

To study the regulation of AUUUA-mediated RNA deadenylation and destabilization during Xenopus early development, we microinjected chimeric mRNAs containing Xenopus or mammalian 3' untranslated region (3'-UTR) sequences into Xenopus oocytes, mature eggs, or fertilized embryos. We found that the AU-rich elements (ARE) of Xenopus c-myc II and the human granulocyte-macrophage colony-stimulating factor gene (GMCSF) both direct deadenylation of chimeric mRNAs in an AUUUA-dependent manner. In the case of the Xenopus c-myc II ARE, mutation of a single AUUUA within an absolutely conserved 11-nucleotide region in c-myc 3'-UTRs prevents ARE-mediated deadenylation. AUUUA-specific deadenylation appears to be developmentally regulated: low deadenylation activity is observed in the oocyte, whereas rapid deadenylation occurs following egg activation or fertilization. Deadenylation results in the accumulation of stable deadenylated RNAs that become degraded only following mid-blastula transition. We conclude that ARE-mediated mRNA deadenylation can be uncoupled from ARE-mediated mRNA decay and that AUUUAs directly signal deadenylation during Xenopus early development.
Mol Cell Biol 1998 Dec
PMID:AUUUA sequences direct mRNA deadenylation uncoupled from decay during Xenopus early development. 981 39

MEN 11,300, MEN 11,301, and MEN 11,303 are three recombinant human hybrid proteins that, as has recently been described, induce in vitro erythroid differentiation. This article provides data on their pharmacokinetic and immunogenic behavior after repeated i.v. administration to cynomolgus monkeys at 0.8 or 1.6 micrograms/kg doses. Pharmacokinetic data, obtained after the first administration, showed that the half-life (t1/2) and clearance (CL) values are dose dependent, with no significant differences among the three hybrid proteins. After the tenth administration, MEN 11,300 and MEN 11,301, both a high and low dose, and MEN 11,303 at high dose were undetectable in plasma, whereas MEN 11,303 at the lower dose showed no alteration in its pharmacokinetic profile. Immunologic analyses of plasma provided an explanation for this different pharmacokinetic behavior. In fact, plasma samples from animals treated repeatedly with MEN 11,300 and MEN 11,301 showed specific antibody formation in response to both the high- and the low-dose regimens. These antibodies exerted in vitro a strong neutralizing activity of the hybrid proteins, with a predominant specificity for the erythropoietin (EPO) portion. By contrast, MEN 11,303 at the lower dose did not induce a detectable antibody response whereas the antibodies observed on the high-dose regimen did not exert neutralizing activity against the hybrid proteins nor against granulocyte-macrophage colony-stimulating factor (GM-CSF) or EPO. Hematologic parameters were not affected by the treatments, thus indicating that the anti-EPO neutralizing antibody response does not cross react with the endogenous monkey cytokine. The overall immunogenicity data suggest that among the three fusion proteins, MEN 11,303 could have a lower immunogenic potential.
Mol Biotechnol 1998 Oct
PMID:Pharmacokinetic and immunogenic behavior of three recombinant human GM-CSF-EPO hybrid proteins in cynomolgus monkeys. 981 12

The alpha subunit of the receptor for human granulocyte-macrophage colony-stimulating factor (GM-CSF) is a 45 kDa membrane protein with a higher apparent molecular weight of 50-85 kDa due to glycosylation. Previously, we had demonstrated that N-glycosylation plays a critical role in the GM-CSF receptor-ligand interaction. To assess the activity of the alpha subunit of the human GM-CSF receptor (GMRalpha) in a lower eukaryote, we expressed GMRalpha in the yeast S. cerevisiae and found that the protein has a lower apparent molecular weight compared with that expressed in mammalian cells. Using indirect immunofluorescence microscopy, we showed that GMRalpha protein expressed in yeast localizes to the plasma membrane. Although the yeast-expressed GMRalpha is able to interact with anti-GMRalpha antibody, the heterologously expressed receptor does not bind GM-CSF. Our results indicate that specific sites and/or forms of glycosylation of the GM-CSF receptor are crucial for ligand binding.
Cytokines Cell Mol Ther 1998 Sep
PMID:Expression of the human GM-CSF receptor alpha subunit in Saccharomyces cerevisiae. 982 39

An in vitro carcinogenesis model of human skin keratinocytes has been developed based on the spontaneously immortalized keratinocyte cell line HaCaT. Immortalization, the initial stage in human carcinogenesis in vitro, was induced by ultraviolet-type mutations in the p53 gene followed by further genetic alterations leading to the loss of senescence genes, in particular on chromosome 3p. Despite multiple genetic changes, the HaCaT cell line sustained its genomic balance up to high passage levels and maintained a non-tumorigenic phenotype. Tumorigenic transformation was induced by ras oncogene transfection but also by culture stress and elevated temperature, resulting in benign and malignant tumorigenic clones. Malignant conversion was associated with the loss of a copy of chromosome 15, leading to a decrease in thrombospondin-1 (TSP-1) expression. Heat-induced malignant conversion was associated with a gain of material on chromosome 11, including the cyclin D1 gene. The microenvironment plays a major role in tumorigenic transformation and the control of malignant cells. Overexpression of platelet-derived growth factor in HaCaT cells caused mesenchyme activation and formation of benign tumors. Halting tumor angiogenesis completely prevented invasion of malignant cells and induced a benign tumor phenotype. Transfer of a normal chromosome 15 or TSP-1 transfection into a skin carcinoma line resulted in tumor suppression due to TSP-1-blocked tumor vascularization. Because of the reduced TSP-1 expression, blood vessels infiltrated the tumor, and it expanded. Progression to more aggressive tumor phenotypes required the in vivo environment and was caused by selection of a subpopulation and further genetic modifications. The improved autonomous growth of these cells was associated with new expression of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor, which acted in an autocrine manner to stimulate proliferation and migration. With this in vitro skin carcinogenesis model we were able to demonstrate multiple stages in the transformation process that were associated with different genetic and phenotypic characteristics. In addition, we documented that modulation of the tumor stroma plays an important and decisive role in tumor development and progression. From this we hypothesize that the growth restraints of the microenvironment are increasingly lost with advancing stages of carcinogenesis but can be restored by modulation of the tumor stroma.
Mol Carcinog 1998 Nov
PMID:Multiple stages and genetic alterations in immortalization, malignant transformation, and tumor progression of human skin keratinocytes. 983 75

Janus kinase 2 (Jak2) protein tyrosine kinase plays an important role in interleukin-3- or granulocyte-macrophage colony-stimulating factor-mediated signal transduction pathways leading to cell proliferation, activation of early response genes, and inhibition of apoptosis. However, it is unclear whether Jak2 can activate these signaling pathways directly without the involvement of cytokine receptor phosphorylation. To investigate the specific role of Jak2 in the regulation of signal transduction pathways, we generated gyrase B (GyrB)-Jak2 fusion proteins, dimerized through the addition of coumermycin. Coumermycin induced autophosphorylation of GyrB-Jak2 fusion proteins, thus bypassing receptor activation. Using different types of chimeric Jak2 molecules, we observed that although the kinase domain of Jak2 is sufficient for autophosphorylation, the N-terminal regions are essential for the phosphorylation of Stat5 and for the induction of short-term cell proliferation. Moreover, coumermycin-induced activation of Jak2 can also lead to increased levels of c-myc and CIS mRNAs in BA/F3 cells stably expressing the Jak2 fusion protein with the intact N-terminal region. Conversely, activation of the chimeric Jak2 induced neither phosphorylation of Shc or SHP-2 nor activation of the c-fos promoter. Here, we showed that the GyrB-Jak2 system can serve as an excellent model to dissect signals of receptor-dependent and -independent events. We also obtained evidence indicating a role for the N-terminal region of Jak2 in downstream signaling events.
Mol Biol Cell 1998 Dec
PMID:Activation and functional analysis of Janus kinase 2 in BA/F3 cells using the coumermycin/gyrase B system. 984 70

We have evaluated the anti-tumor effect of anti-GD2 mouse monoclonal antibody (mAb) 220-51 against human neuroblastoma cell line TGW in vitro and in vivo. The mAb 220-51 was able to mediate complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) using human effector cells. In the presence of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte ADCC was significantly augmented in vitro. When mAb 220-51 was administered to tumor-bearing nude mice, tumor growth was significantly inhibited as compared with untreated controls. Administration of recombinant murine GM-CSF in combination with mAb 220-51 significantly enhanced the anti-tumor effect of mAb in vivo. Recombinant human granulocyte colony-stimulating factor (G-CSF) combined with mAb 220-51 was also able to enhance it, although granulocyte ADCC was not affected by the presence of recombinant human G-CSF in vitro. Moreover, GM-CSF and G-CSF work additively to enhance the anti-tumor effect of mAb 220-51 in vivo. The GM-CSF and G-CSF may have a clinical potency in immunotherapy with anti-GD2 mAb for the treatment of neuroblastoma.
Int J Mol Med 1998 Oct
PMID:Enhancement of in vitro and in vivo anti-tumor activity of anti-GD2 monoclonal antibody 220-51 against human neuroblastoma by granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor. 985 37

Hematopoietic cells require cytokine-initiated signals for survival as well as proliferation. The pathways that transduce these signals, ensuring timely regulation of cell fate genes, remain largely undefined. The NFIL3 (E4BP4) transcription factor, Bcl-xL, and constitutively active mutants of components in Ras signal transduction pathways have been identified as key regulation proteins affecting murine interleukin-3 (IL-3)-dependent cell survival. Here we show that expression of NFIL3 is regulated by oncogenic Ras mutants through both the Raf-mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways. NFIL3 inhibits apoptosis without affecting Bcl-xL expression. By contrast, Bcl-xL levels are regulated through the membrane proximal portion in the cytoplasmic domain of the receptor (betac chain), which is shared by IL-3 and granulocyte-macrophage colony-stimulating factor. Activation of either pathway alone is insufficient to ensure cell survival, indicating that multiple independent signal transduction pathways mediate the survival of developing B-lymphoid cells.
Mol Cell Biol 1999 Apr
PMID:Two distinct interleukin-3-mediated signal pathways, Ras-NFIL3 (E4BP4) and Bcl-xL, regulate the survival of murine pro-B lymphocytes. 1008 41

Interleukin-10 (IL-10) has potent anti-inflammatory and immunosuppressive properties. The potential therapeutic benefit may be compromised by the down-regulation of the non-specific immune system and an increased risk of infection. We studied the effects of IL-10 on important functions of native and granulocyte-macrophage colony-stimulating factor (GM-CSF) activated neutrophils and monocytes, namely phagocytosis and membrane expression of the beta superset2-integrins and of the intercellular adhesion molecule-1 (ICAM-1). In order to simulate the in vivo situation closely, we used whole blood flowcytometric assays. The effects of IL-10 (0.05, 1, 10, 100 ng/ml) were compared to those of prednisolone (10 superset-8-10 superset-5 Mol/l), an approved immunosuppressive drug which is known to impair phagocyte function. - Incubation with IL-10 for three hours significantly attenuated the ability of neutrophils to phagocytose E.coli, particularly in lower concentrations. On the other hand, high IL-10 concentrations (10, 100 ng/ml) slightly augmented monocyte phagocytosis. Similarly, expression of the beta subset2-integrins and of ICAM-1 on monocytes was markedly enhanced with IL-10 concentrations in the range from 1 to 100 ng/ml and IL-10 showed strong synergistic effects with GM-CSF in the enhancement of monocyte receptor expression. Neutrophil adhesion molecule expression was not affected. Prednisolone suppressed the phagocytosis of both cell types in a dose-dependent fashion but hardly altered the receptor numbers. Our study indicates that IL-10 can behave as a de-activator as well as an activator on the non-specific immune system, depending on the cell type and the concentration.
 ...
PMID:Interleukin-10: effects on phagocytosis and adhesion molecule expression of granulocytes and monocytes in a comparison with prednisolone. 1008 74

Colony-stimulating factor 1 (CSF-1) triggers the activation of intracellular proteins in macrophages through selective assembly of signalling complexes. The separation of multimeric complexes of the CSF-1 receptor (CSF-1R) by anion-exchange chromatography enabled the enrichment of low-stoichiometry complexes. A significant proportion of the receptor in CSF-1-stimulated cells that neither possessed detectable tyrosine kinase activity nor formed complexes was separated from the receptor pool displaying autokinase activity that formed chromatographically distinct multimeric complexes. A small pool of CSF-1R formed a multimeric complex with phosphatidylinositol-3 kinase (PI-3 kinase), SHP-1, Grb2, Shc, c-Src, Cbl, and a significant number of tyrosine-phosphorylated proteins in CSF-1-stimulated cells. The complex showed a considerable amount of CSF-1R complex-associated kinase activity. A detectable level of the complex was also present in untreated cells. PI-3 kinase in the multimeric complex displayed low lipid kinase activity despite the association with several proteins. The major pool of activated CSF-1R formed transient multimeric complexes with distinctly different tyrosine-phosphorylated proteins, which included STAT3 but also PI-3 kinase, Shc, SHP-1, and Grb2. A significant level of lipid kinase activity was detected in PI-3 kinase in the latter complexes. The different specific enzyme activities of PI-3 kinase in these complexes support the notion that the activity of PI-3 kinase is modulated by its association with CSF-1R and other associated cellular proteins. Specific structural proteins associated with the separate CSF-1R multimeric complexes upon CSF-1 stimulation and the presence of the distinct pools of the CSF-1R were dependent on the integrity of the microtubular network.
Mol Cell Biol 1999 Jun
PMID:Separation and characterization of the activated pool of colony-stimulating factor 1 receptor forming distinct multimeric complexes with signalling molecules in macrophages. 1033 Jan 48


<< Previous 1 2 3 4 5 6 7 8 9 10