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)

Cholinergic agonists inhibit the basal and PGE1-activated adenylate cyclase activity in membranes isolated from the mouse neuroblastoma x glioma hybrid cell NG108-15. Inhibition is observed with acetylcholine, acetyl-beta-methylcholine and carbachol and is blocked by two specific muscarinic antagonists, atropine and quinuclydinylbenzilate. Inhibition of basal and PGE1-activated activity is only partial. Carbachol-directed inhibition has an apparent Km of 6 microM in the presence or absence of PGE1. Both the guanine nucleotide GTP and the monovalent cation Na+ are required for this muscarinic inhibition of basal and PGE1-activated NG108-15 adenylate cyclase. The selectivity observed for monovalent cations (all chloride salts) in this process is Na+ congruent to Li+ greater than K+ greater than Choline+ with the ED50 for Na+ congruent 40 microM. Of the nucleotides tested, only IT (and not ATP, UTP or CTP) replaces GTP in this process. GTP at 10 microM represents a saturating nucleotide concentration. Opiate-directed inhibition of NG108-15 adenylate cyclase has recently been shown to exhibit a similar requirement for GTP and Na+ [Blume, A. J., Lichtshtein, D. and Boone, G. (1979) Proc. National Academy of Sciences, USA, in press]. The data presented here therefore support the hypothesis that the general transfer of inhibitory information from membrane receptors to adenylate cyclase involves both a Na+ and GTP-sensitive process.
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PMID:Muscarinic receptor regulation of NG108-15 adenylate cyclase: requirement for Na+ and GTP. 52 45

Growth studies were done on a cultured rat liver cell line (RLC-GAI) grown in a chemically defined medium in the presence of lead nitrate. Lead reversibly inhibited the growth of these cells even after 6 d of exposure to the heavy metal. To compare lead sensitivity in various cell lines, GI50 and LD50 values were determined in the RLC-GAI cells as well as two glioma cell lines (B82 and C(6)) and a neuroblastoma cell line (N18). The LD50 values paralleled but were consistently lower than the GI50 values. Since lead is known to affect heme synthesis, hemin was added to test the possibilty of preventing the growth-inhibitory effect of the lead. The growth capacity of lead-treated cells did not change with the addition of hemin. It is thought that differentiated cultured cell lines such as these could be useful in examining the molecular mechanism of lead toxicity.
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PMID:Cellular and molecular toxicology of lead. I. Effect of lead on cultured cell proliferation. 56 52

Extracts prepared from several lines of transformed cells were examined for the presence of cellular binding proteins specific for retinoids. Extracts of human retinoblastoma cell line WERI-Rb1 contained a cellular binding protein specific for retinoic acid, whereas extracts of human retinoblastoma cell line Y-79 contained cellular binding proteins for both retinol and retinoic acid. Upon purification, the latter two binding proteins proved to have properties similar to those of the corresponding proteins obtained from bovine retina. Smaller amounts of these binding proteins were detected in extracts of undifferentiated and differentiated neuroblastoma and McCoy cells. HeLa and rat glioma cells had no detectable amount of binding proteins. The 11-cis-retinal-binding protein, present in extracts of human, rat, and bovine retina, was not found in any of the cell lines examined.
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PMID:Cellular retinol- and retinoic acid-binding proteins in transformed mammalian cells. 56 21

The stability of a clonal mouse neuroblastoma x rat glioma hybrid cell line was examined. Cell volume and cellular content of DNA and protein were measured as functions of the passage number. They decreased with the number of serial subcultivations. Cellular volume was linearly related to cellular DNA and protein. Thus, measurements of cell volume can be used to monitor the loss of DNA from hybrid cells. After about 60 passages a stable population of hybrid cells arose, as judged by the constancy of cellular volume and by the decreased coefficient of variation of the cell volume distribution. A mathematical model for the kinetics of the simultaneous loss of cellular volume, DNA and protein is introduced. Several neuronal properties were investigated. The specific activity of the neurotransmitter enzyme choline acetyltransferase decreased by more than 50% during 56 passages. After 70 subcultivations, the hybrid cells were still capable of extending processes, action potentials could still be elicited electrically or by iontophoretic application of acetylcholine, and the cells still responded to prostaglandin E1 as they do at low passage number.
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PMID:Influence of the time in culture on cellular and neuronal properties of neuroblastoma x glioma hybrid cells. With an appendix, mathematical description of the kinetics of the loss in cell volume. 59 72

Mouse neuroblastoma clone N18, rat glioma clone C6, and rat striated muscle clone L6 were grown in a serum-free Dulbecco's modified Eagle's medium. Their doubling times were 48 hours, 40 hours, and 4 days, respectively. Morphologic features were similar to the original parent cell lines. Membrane components of N18 and C6 grown in serum-free medium were compared with the original parent cell lines. Defects of several membrane proteins were found with sodium dodecyl sulfate--polyacrylamide gel electrophoresis.
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PMID:Establishment of mouse neuroblastoma clone N18, rat glioma clone C6, and rat striated muscle clone L6 in serum-free, chemically defined medium. 74 55

Cultured neuroblastoma-glioma hybrid cells and primary mouse and rat muscle cells were studied by using intracellular microelectrodes to monitor membrane electrical potential and resistance changes during complement-mediated lysis. The cell membrane was TNP modified under mild conditions and subsequently coated with rabbit IgG anti-TNP, with no electrical changes observed. However, upon addition of guinea pig C the membrane potential dropped from approximately -50 mv to less than -12 mv within a few minutes, with parallel decreases in electrical resistance. Ten to 60 min after these electrical changes the cells became stainable with trypan blue. No electrical changes or trypan blue staining was observed in the absence of antibody or with heat-inactivated C. With more dilute C so that only a fraction of cells became trypan blue positive, all cells nevertheless showed the membrane electrical changes; surviving cells recovered their original membrane properties within 1 hr. Thus the C-mediated damage to the membrane measured electrically is not in itself sufficient to ensure the subsequent death of the cell. The early electrical changes observed appear to be comparable to increases in 86Rb efflux measured by others.
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PMID:Electrical measurements of complement-mediated membrane damage in cultured nerve and muscle cells. 76 31

Electrical excitability is one of the various neuronal properties of neuroblastoma X glioma hybrid cells. At a Ca2+ concentration of 1.8 mM the action potential is inhibited by tetrodotoxin, suggesting that the inward current is carried by Na+ ions. In contrast, at a Ca2+ concentration of 20-36 mM and even in the absence of Na+, spikes (sometimes repetitive) with strong hyperpolarizing afterpotential occur, which are no longer affected by tetrodotoxin. They are, however, blocked by antagonists of Ca2+ like La3+, Co2+, Mn2+, and the synthetic compounds D-600 and BAY a-1040. This seems to indicate that at high concentrations of Ca2+, the inward current of the action potential is essentially carried by Ca2+. Sr2+, but not Mg2+ can effectively substitute for Ca2+. It slows down the time course of the action potential. Ba2+ depolarizes the membrane gradually. If Ca2+ is also present, Ba2+ causes a reduced depolarization and spontaneous action potentials with no hyperpolarizing after-potential are observed.
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PMID:Influence of cations on the electrical activity of neuroblastoma X glioma hybrid cells. 89 Apr 47

The metabolism of putrescine in neuroblastoma and glioma cells was analyzed during culture. In the former cells the formation of gamma-aminobutyric acid from putrescine was low and constant during the logarithmic phase and increased dramatically during the stationary phase or in cultures with low serum concentrations, while in the latter cells it was low and constant throughout culture. The formation of spermidine from putrescine in both cell lines was active at days 1-2 of culture and decreased gradually during culture. These findings indicate that spermidine formation is closely related to proliferation of the cells, and gamma-aminobutyric acid formation to differentiation or maturation of the neuroblastoma cells.
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PMID:Metabolism of putrescine in neuroblastoma and glioma cells during culture. 92 85

Two cell surface antigens on rat neural tumor cells are defined by antisera from mice immunized with a rat glioma cell line, 33B. The Common antigen is on rat brain and embryo, and is strongly expressed on the surface of all, or most, rat glioma and neuroblastoma cell lines and tumors. The other Restricted antigen is not present at detectable levels on normal rat tissues, but is on 33B, and on 11 other rat neural tumors or cell lines developed from such tumors, though many other tumors are negative. These 2 antigens are on cell membrane preparations from cells and tumors, and have been further characterized using a quantitative antigen assay. Both antigens are heat labile, and can be destroyed by digestion with proteolytic enzymes. The Common antigen is 10 times more sensitive than the restricted antigen to pronase digestion. Furthermore, spacially separate sites for the 2 antigens are indicated by blocking experiments with pepsin digested antisera. Attempts to purify these antigens further have been frustrated by loss of antigenic activity upon detergent-induced release from the membrane. The tissue and tumor distributions of recently described mouse and rat surface antigens are reviewed. Many of these antigens are present on both brain and kidney, but not on other tissues, though several are shared with embryonic cells or sperm. Several new antigens have been described which may be neuronal specific.
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PMID:Biochemical studies of the common and restricted antigens, two neural cell surface antigens. 92 49

Three neuroblastoma systems were used to define fucose-containing glycopeptides on the cell surface and to relate them to the phenotypic expressions of neuronal functions. These systems were a) clonal lines of mouse neuroblastoma C-1300, b) cell hybrids of mouse neuroblastoma and rat glioma, and c) human neuroblastomas, primary cells from the tumor, and cell lines. The results suggest that similarities exist in the membrane glycopeptides available at the surface of the mouse and human cells. It is proposed that these similarities correspond to the ability of the cells to perform the differentiated functions of neuronal cells or to exist as tumors. Based on analogy with other cell membranes, a schema is given for the structure of the membrane glycopeptides on the neuroblastoma cell.
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PMID:Glycoproteins on the surface of neuroblastoma cells. 97 72


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