Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In rat glioma C6 cells, extracellular ATP stimulated phosphoinositide (PI) hydrolysis in concentration- and time-dependent manners with a median effective dose value of 60 microM. The maximal response was attained at 300 microM ATP. Of adenine nucleotides, ATP and adenosine 5'-O-(3-thiotriphosphate) were most effective, while adenosine, AMP and beta,gamma-methylene ATP were ineffective. Similar results were obtained in cultured rat astrocytes. The stimulatory effects of ATP and ADP were negated by removal of external Ca++ in C6 cells. ATP at 300 microM induced an elevation of intracellular Ca++ concentration in 1-[2-(5-carboxyoxazol-2-yl)-6-amino-benzofuran-5-oxy]-2-(2'-amino- 5'- methylphenoxy)-ethane-N,N,N',N' acid-loaded C6 cells. This response was not blocked by nifedipine (10 microM) and verapamil (10 microM). A Ca++ ionophore A23187 (10 microM) stimulated PI hydrolysis in C6 cells. The responses to ATP (300 microM) and A23187 (10 microM) were additive. In digitonin-permeabilized C6 cells, Ca++ at the concentration of 100 microM evoked PI hydrolysis, and ATP alone did not affect the Ca++ dependence. GTP gamma S (100 microM) stimulated the PI hydrolysis at a range of 0.1 to 10 microM Ca++, and ATP enhanced the GTP gamma S response in the permeabilized cells. These results suggest that activation of P2-purinergic receptors by ATP causes phospholipase C to be activated by subthreshold concentrations of Ca++ via GTP-binding proteins, resulting in an activation of the enzyme in response to stimulated Ca++ influx.
J Pharmacol Exp Ther 1992 Dec
PMID:Mechanism of extracellular ATP-stimulated phosphoinositide hydrolysis in rat glioma C6 cells. 133 61

The 5'-flanking region of the calcineurin A alpha gene was isolated from a rat genomic library. It lacked TATA and CAAT boxes but contained G+C-rich regions, and was demonstrated to function as a strong promoter in neuronal cell lines (NG108-15 mouse neuroblastoma x rat glioma hybrid cells or N1E115 mouse neuroblastoma cells), but not in nonneuronal cell lines (C6 rat glioma or L-M mouse fibroblastoid cells) in a transient chloramphenicol acetyltransferase expression assay. Deletion analysis of the 5'-flanking region revealed that the core promoter region, as well as the sequence critical for cell-type-specific-promoter function, reside within the fragment -107 to +157 with respect to the major transcription initiation site.
Biochem J 1992 Dec 15
PMID:Molecular cloning and characterization of the promoter region of the calcineurin A alpha gene. 133 33

To elucidate the mechanisms of the intracellular signal transduction elicited with bradykinin in NG108-15 neuroblastoma x glioma hybrid cells, we examined the activation of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) by bradykinin stimulation. When the extract of NG108-15 cells was immunoprecipitated with the affinity-purified antibody to brain CaM kinase II, a 50-kDa protein in the immunoprecipitate mainly became autophosphorylated in a Ca2+/calmodulin-dependent manner. The results suggest that the 50-kDa protein is the subunit of CaM kinase II in NG108-15 cells. The Ca2+/calmodulin-independent activity (autonomous activity) of the enzyme increased twice within 10 s by stimulation with 1 microM bradykinin in the cells. The increase in the autonomous activity of the enzyme had two phases: the transient early-peak phase and the long late-plateau phase. The former was abolished by the pretreatment of the cells with 10 mM caffeine or 20 microM BAPTA-AM, and the latter was abolished by the removal of the extracellular Ca2+ with 1 mM EGTA or by the pretreatment with 1 microM nifedipine. Stimulation of 32P-labeled NG108-15 cells with 1 microM bradykinin increased the autophosphorylation of CaM kinase II and this increase was abolished by pretreatment with caffeine or BAPTA-AM. These results suggest that CaM kinase II is activated via the inositol phospholipid signaling pathway induced with bradykinin in NG108-15 cells.
Brain Res 1992 Dec 04
PMID:Activation of Ca2+/calmodulin-dependent protein kinase II by stimulation with bradykinin in neuroblastoma x glioma hybrid NG108-15 cells. 133 47

Interactions between beta-adrenergic and ADP purinergic receptors in C6 glioma cell membrane preparations were investigated under steady state and then pre-steady state conditions of adenylyl cyclase (EC 4.6.1.1) activity, in order to determine how fast the second receptor antagonizes the transduction mechanism of the first. Cell membranes were washed to deplete them as thoroughly as possible of low molecular weight compounds, especially ATP and ADP, and to ensure better control of both substrate and agonist nucleotide concentrations. ATP concentrations were kept constant with the use of an ATP-regenerating system; the C6 cell line exhibited very active ectonucleotidases. The purinergic agonist ADP was replaced by its nonhydrolyzable congener adenosine 5'-O-(2-thio)diphosphate (ADP beta S), which was demonstrated, like ADP, to inhibit isoproterenol-stimulated adenylyl cyclase activity in intact cells (IC50 for ADP, 0.5 +/- 0.1 microM; IC50 for ADP beta S, 25 +/- 2 microM) and in membrane preparations (IC50 for ADP beta S, 79 +/- 20 microM). In the case of membrane preparations, ADP beta S did not compete with ATP, the substrate of the cyclase-catalyzed reaction, and behaved apparently as a non-competitive inhibitor of the enzyme. The pre-steady state kinetics of isoproterenol-stimulated adenylyl cyclase activity measured with a pulsed quenched-flow apparatus have previously been shown to include two steps, the first very rapid (taking place within 1-2 sec) and giving rise to a burst of cAMP synthesis and the second much slower and corresponding to the steady state reaction. ADP beta S inhibited the occurrence of both steps with comparable IC50 values (mean value, 55 +/- 20 microM). In the presence of increasing concentrations of the purinergic receptor agonist, the time constant of the exponential burst reaction was not affected, but its amplitude progressively decreased to zero. These results showed that the extinction of the beta receptor cAMP response by the purinergic ADP receptor occurred within the dead-time of the pulsed quenched-flow apparatus, which was 50 msec. Such a rapid inhibition of cAMP production excluded modulation of isoproterenol-stimulated adenylyl cyclase activity by the ADP receptor by a pathway other than its direct negative coupling to the cyclase via a Gi protein. In this respect, the P2 purinergic ADP receptor of the C6 glioma cell line appears comparable to the P2t receptor of platelets.
Mol Pharmacol 1992 Dec
PMID:Pre-steady state study of beta-adrenergic and purinergic receptor interaction in C6 cell membranes: undelayed balance between positive and negative coupling to adenylyl cyclase. 133 11

A murine model for meningeal metastasis of malignant glioma was developed to study selective gene transfer into tumor cells and to establish a reliable means of determining the rate of tumor cell infection. A murine ecotropic retroviral vector was created in which the Escherichia coli beta-galactosidase gene served as a marker for gene expression from the integrated retrovirus. This retrovirus exhibited a high rate of infectivity in RSV-M mouse glioma cells in vitro. The recombinant retrovirus was injected directly into the cisterna magna of the mice. Staining of beta-galactosidase showed that the rate of gene integration was high in the disseminated glioma cells. These results suggest the possibility of retrovirus-mediated gene therapy for meningeal dissemination of malignant glioma.
Jpn J Cancer Res 1992 Dec
PMID:Retrovirus-mediated gene transfer targeted to malignant glioma cells in murine brain. 133 95

The human glioma cell lines U251 and HP591 were chosen as "in vitro" models for functional astrocytes. When cultured in the presence of IL-1 beta these cell lines demonstrated a marked increase in interleukin-6 production and in [3H]-thymidine uptake. The addition of dbcAMP could mimic the first effect of IL-1 beta but at the same time suppressed cell proliferation. These results suggest that IL-1 beta possibly exerts one of its biological effects (IL-6 synthesis) by means of the cyclic AMP pathway.
Immunol Lett 1992 Dec
PMID:"In vitro" effect of interleukin-1 beta on human glioma cell lines: regulation of cell proliferation and IL-6 production. 133 65

The effect of the combination of adriamycin (ADM) with the anti-inflammatory drug rhein (RH) on the membrane redox activity in human glioma cells was investigated. RH, although less effective than ADM, inhibits ferricyanide reduction by human glioma cells in a dose-dependent manner as well as ferricyanide-induced proton release. The inhibition of the plasma membrane redox system might represent a further mechanism by which RH, other than ATP depletion, affects cell survival. The analysis of the interaction between ADM and RH, performed with the isobolar method, demonstrates a strong synergic response, probably due to an effect on different sites of action. The synergism of the ADM-RH association allows us to achieve a pre-established extent of inhibition with ADM concentrations much lower than with ADM alone. RH might, therefore, represent a very useful tool to improve the therapeutic index of ADM and to lower its general toxicity.
Anticancer Drugs 1992 Dec
PMID:Inhibition of membrane redox activity by rhein and adriamycin in human glioma cells. 133 5

Congenital brain tumor is a rare disease in the neonatal period. According to the literatures, they comprise only about 1% of childhood brain tumors. Among the congenital brain tumors, 10%-25% are astrocytomas. Anaplastic astrocytoma is one of the malignant glioma. The prognosis is usually not good in the childhood or adult stage. We report one case of congenital anaplastic astrocytoma who received combination chemotherapy, including vinblastine, cisplatin and etoposide following subtotal resection of tumor. After chemotherapy, he got a favorable outcome. And now, he is still no evidence of tumor recurrence for two years.
Zhonghua Yi Xue Za Zhi (Taipei) 1992 Dec
PMID:[Successful treatment of congenital anaplastic astrocytoma by combining vinblastine, cisplatin and etoposide: a case report]. 133 32

A study of the intracellular Ca2+ ([Ca2+]i) response of differentiated neuroblastoma x glioma hybrid cells (NG108-15 cell) to enkephalin (EK) was carried out by fura-2 video-imaging. EK alone did not influence [Ca2+]i in single cells. The opioid did, however, induce a marked [Ca2+]i rise, when the cells were incubated with bradykinin (BK) prior to the EK treatment. Such BK-assisted stimulation of the differentiated hybridoma cells by EK was completely abolished by pertussis toxin treatment. These results suggest that in single NG108-15 cells, EK induces Ca2+ mobilization which is assisted by cross-talk between the EK and BK receptor systems via a pertussis toxin-sensitive G protein.
Neurosci Lett 1992 Dec 14
PMID:Enkephalin induces Ca2+ mobilization in single cells of bradykinin-sensitized differentiated neuroblastoma hybridoma (NG108-15) cells. 133 52

Human immunodeficiency virus (HIV-1) infection in the human brain leads to characteristic neuropathological changes, which may result indirectly from interactions of the envelope glycoprotein gp120 with neurons and/or glial cells. We therefore investigated the binding of recombinant gp120 (rgp120) to human neural cells and its effect on intracellular signalling. Here we present evidence that rgp120, besides binding to galactocerebroside or galactosyl-sulfatide, specifically binds to a protein receptor of a relative molecular mass of approximately 180,000 Da (180 kDa) present on the CD4-negative glioma cells D-54, but not on Molt4 T lymphocytes. Binding of rgp120 to this receptor rapidly induced a tyrosine-specific protein kinase activity leading to tyrosine phosphorylation of 130- and 115-kDa proteins. The concentration of intracellular calcium was not affected by rgp120 in these cells. Our data suggest a novel signal transducing HIV-1 gp120 receptor on CD4-negative glial cells, which may contribute to the neuropathological changes observed in HIV-1-infected brains.
Virology 1992 Dec
PMID:HIV-1 gp120 receptor on CD4-negative brain cells activates a tyrosine kinase. 136 Jan 81


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