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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuroblastoma clones were examined for choline acetyltransferase (EC 2.3.1.6), tyrosine hydroxylase (EC 1.14.3.a), acetylcholinesterase (EC 3.1.1.7), and also for neurite formation. One clone does not form axons or dendrites. Three types of clones were found with respect to neurotransmitter synthesis: cholinergic, adrenergic, and clones that do not synthesize acetylcholine or catechols. All clones contain acetylcholinesterase. These results show that genes determining neurotransmitter species can be expressed in dividing cells, that the parental programs of gene expression are inherited, and that dividing cells can be programmed with respect to their ability to communicate with other cells.
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PMID:Neurotransmitter synthesis by neuroblastoma clones (neuroblast differentiation-cell culture-choline acetyltransferase-acetylcholinesterase-tyrosine hydroxylase-axons-dendrites). 440 Feb 94

Addition of acetylcholine to growing cultures of mouse neuroblastoma cells induced a 37-fold increase in the specific activity of acetylcholinesterase (EC 3.1.1.7). Morphological changes, consisting of neurite-extensions, were also observed during the logarithmic phase of growth of cells stimulated with acetylcholine. A histochemical procedure for localization of acetylcholinesterase was used with the following results: (a) Cells differentiating by growth inhibition in serum-free medium do not stain positively for acetylcholinesterase, except when they have extended neurites, whereas all cells induced with acetylcholine, with or without neurites, stain positively for the enzyme. (b) The inverse relation between cell growth and induction of enzyme activity was demonstrated in nondividing cells at the center of a colony that do not incorporate thymidine into DNA and that stain positively for acetylcholinesterase, whereas actively dividing cells on the periphery of the colony do not stain for the enzyme. However, by addition of acetylcholine we were able to dissociate inhibition of cell growth from biochemical and morphological differentiation in mouse neuroblastoma cells.
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PMID:Induction of neuronal functions: acetylcholine-induced acetylcholinesterase activity in mouse neuroblastoma cells. 450 10

Purified alpha-toxin from Naja nigricollis snake venom labeled by [(3)H]acetylation binds specifically to the acetylcholine receptors of mouse neuroblastoma cells. Toxin binding was inhibited by inhibitors for nicotinic and muscarinic acetylcholine receptors. Clones of neuroblastoma cells were selected for low acetylcholinesterase (EC 3.1.1.7) activity with antibodies against this enzyme. Selection for an 80-fold decrease in acetylcholinesterase activity was not associated with any decrease in the number of acetylcholine receptors (3.4 x 10(7) per cell). Removal or inactivation of 80% of the acetylcholine receptors by proteolytic enzymes or by compounds that block sulfhydryl groups did not change the activity of acetylcholinesterase on the cell surface. In addition to these results on the separation between acetylcholine receptors and acetylcholinesterase, a common regulation was found in that both the number of acetylcholine receptors and the activity of acetylcholinesterase were increased 5- to 10-fold when the cells stopped to multiply or were induced to differentiate by dibutyryl-cyclic AMP. It is suggested that there are different genes for the acetylcholine receptor and acetylcholinesterase, and that both are regulated during growth and differentiation by a common regulatory gene.
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PMID:Regulation of acetylcholine receptors in relation to acetylcholinesterase in neuroblastoma cells. 451 44

The specific activity of mouse neuroblastoma acetylcholinesterase (EC 3.1.1.7) increased 25-fold when the rate of cell division was restricted. The results show that acetylcholinesterase activity is regulated in neuroblastoma cells and that the regulatory mechanism is inversely related to the rate of cell division. Under the same conditions the specific activity of catechol-O-methyl transferase (EC 2.1.1.6) did not change significantly.
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PMID:Regulation of acetylcholinesterase in neuroblastoma cells. 528 21

As part of an investigation of the organization of cell surface macromolecular assemblies, we have treated intact central nervous system cells with chemical probes which react convalently with proteins and aminophospholipids. Selective alterations of the enzymatic activities of ecto-ATPases, ecto-5'-nucleotidases and cholinesterases were obtained under appropriate reaction conditions. The cross-linking reagent, 1,5-difluoro-2,4-dinitrobenzene, was a potent inactivator of ecto-ATPase of C6 glioblastoma, IMR-32 neuroblastoma and of a primary rat astroblast cell line (RB). Ecto-5'-nucleotidase and acetylcholinesterase were less sensitive to difluorodinitrobenzene. 1-Fluoro-2,4-dinitrobenzene at concentrations which inactivated ecto-ATPase had little effect on ecto-5'-nucleotidase. Conversely, 2,4,6-trinitrobenzenesulfonic acid was a potent inactivator of ecto-5'-nucleotidase but had no effect on ecto-ATPase. The difluorodinitrobenzene inactivation of ecto-ATPase and of ecto-5'-nucleotidase as well as the fluorodinitrobenzene inactivation of ecto-ATPase could be prevented by the presence of the appropriate substrates in the reaction medium. In the presence of protecting nucleotide substrates, a decrease in reactivity with proteins and lipids was observed when the isotopic probe fluorodinitro[3H]-benzene was used.
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PMID:Selective chemical modification of plasma membrane ectoenzymes. 611 44

Mouse neuroblastoma cells (Clone NIR-115) were grown in serum-free (defined) medium, defined medium supplemented with serum, and control medium to determine whether serum-free medium could substitute for serum-containing medium in our studies of the histamine H1 and muscarinic acetylcholine receptors of these cells. The function of these receptors as determined by measurement of receptor-mediated cyclic [3H]GMP formation was absent in cells grown in serum-free medium and increased as the percentage of serum was increased in the defined medium, but never attained the levels found with control cells. Muscarinic receptor number for cells grown in defined medium was 60% above that found for control cells with no change in the affinity of the receptor for the radioligand (--)[3H]quinuclidinyl benzilate. Guanylate cyclase and acetylcholinesterase activities for cells grown in defined medium were 23 and 66% of those found in control cells, respectively. This marked reduction of guanylate cyclase activity in large part explains the lack of function of these receptors.
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PMID:Lack of function of histamine H1 and muscarinic acetylcholine receptors of mouse neuroblastoma cells grown in serum-free medium. 612 10

The regulation of cyclic adenosine 3':5'-monophosphate (cAMP)-binding protein in N-18 neuroblastoma cells in tissue culture was studied by the covalent incorporation of 8-azido-cyclic adenosine 3':5'-[32P]monophosphate, together with the techniques of sodium dodecyl sulfate:polyacrylamide gel electrophoresis and autoradiography. Greater than 95% of the total cAMP binding activity of N-18 neuroblastoma cells was identified as being regulatory subunits of the type I (RI) and type II (RII) species, with RI being the predominant form of the two (RI:RII = 3:1). The specific activity of RI but not of RII increased 3-fold when cells were grown in medium containing 1% rather than 10% fetal calf serum. Under the same conditions, the specific activity of acetylcholinesterase increased 3- to 5-fold. The increase in RI was inversely related to the serum concentration in the medium and was specific for cells at the stationary phase of growth. An increase in intracellular cAMP, concomitant with the increase in RI, was also observed. Morphological examination of stationary-phase neuroblastoma cells maintained in medium containing 1% fetal calf serum suggested the presence of a high proportion of highly-differentiated cells. It is proposed that the regulatory control of RI cAMP-binding protein by serum may involve modulation of intracellular cAMP and that the expression RI may be used as a biochemical index of differentiation in mouse neuroblastoma cells.
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PMID:Regulation of cyclic adenosine 3':5'-monophosphate-binding protein in N-18 mouse neuroblastoma cells. 625 72

The expression of a adenosine cyclic 3':5'-monophosphate (cAMP)-binding protein, regulatory subunit of the type I cAMP-dependent protein kinase (Rl), and its functional significance in the differentiation of N-18 mouse neuroblastoma cells were examined. 8-Azidoadenosine cyclic 3':5'-[32P]monophosphate, a photoaffinity-labeling analog of cAMP, and high-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to identify and quantitate cAMP-binding proteins in cell extracts. The induction of differentiation of N-18 mouse neuroblastoma cells, initiated either by adding dibutyryl adenosine cyclic 3':5'-monophosphate to the growth medium or by culturing cells in medium supplemented with 1% fetal calf serum, led to a 3-fold increase in the amount of 8-azidoadenosine cyclic 3':5'-[32P]monophosphate incorporated into Rl, when assayed in vitro. This increased incorporation was attributable to an increase in the amount of Rl rather than to an increase in the affinity of Rl for 8-azidoadenosine cyclic 4':5'-[32P]monophosphate. The subunit molecular weight, isoelectric point, and immunoreactivity of Rl were found to be identical to that of the regulatory subunit of the type I cAMP-dependent protein kinase purified from bovine skeletal muscle. The increase in Rl was not accompanied by an increase in the cAMP-dependent protein kinase activity. DEAE-cellulose column chromatography confirmed the induction of Rl as a free cAMP-binding protein in the differentiated neuroblastoma cells. The possibility of a growth-dependent regulation of Rl was also examined. Addition of 2% dimethyl sulfoxide to cultures of N-18 mouse neuroblastoma cells inhibited cell growth without increasing the specific activity of Rl. Dimethyl sulfoxide had no effect on neurite outgrowth or acetylcholinesterase activity, two parameters characteristic of differentiated cells. The fact that the induction of Rl coincided with differentiation of the neuroblastoma cells suggests that the expression of Rl may be used as a biochemical index of differentiation in these cells. The presence of a free cAMP-binding protein, not associated with cAMP-dependent protein kinase in neuroblastoma cells, raises important considerations concerning the action of cAMP in the regulation of growth and differentiation.
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PMID:Induction of the regulatory subunit of type I adenosine cyclic 3':5'-monophosphate-dependent protein kinase in differentiated N-18 mouse neuroblastoma cells. 627 81

The possible functions of ornithine decarboxylase (ODC) and polyamines in the differentiation of mouse NB-15 neuroblastoma cells were investigated by examining the changes of these parameters in the differentiating and nondifferentiating NB-15 cells over a 5-day culture period. Differentiation of NB-15 cells was induced by the addition of dibutyryl cyclic AMP and 3-isobutyl-1-methylxanthine (1BMX) to the growth medium and was monitored by neurite outgrowth, increases of acetylcholinesterase (AChE), and RI cAMP-binding protein. Plating of NB-15 cells in fresh serum-containing growth medium was accompanied by rapid growth and a marked increase of ODC activity; this early increase of ODC activity was attenuated, both in duration and in magnitude, in the differentiating cells. The spermidine content of the differentiating neuroblastoma cells was significantly lower than that of the nondifferentiating cells. In the fully differentiated neuroblastoma cells, the ODC activity and spermidine content were lower than that of the undifferentiated cells by approximately 15-fold and five-fold, respectively. Based on these results it is proposed that changes of polyamine metabolism may be of significance in the differentiation of mouse neuroblastoma cells.
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PMID:Changes of ornithine decarboxylase activity and polyamine content upon differentiation of mouse NB-15 neuroblastoma cells. 628 99

(R, S)-alpha-Fluoromethylornithine (alpha-FMO), a catalytic irreversible inhibitor of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17), induced the differentiation of N2a mouse neuroblastoma cells. The effect of alpha-FMO was concentration dependent; approximately 50% of the cell population exhibited neurite outgrowth in the presence of 1 mM alpha-FMO, while higher concentrations caused severe growth inhibition and cell death. The effect of 1 mM alpha-FMO on neuroblastoma differentiation was potentiated greatly by 0.1 to 0.2 mM N6,O2'-dibutyryl adenosine cyclic 3':5'-monophosphate (Bt2cAMP) causing more than 90% of the cell population to differentiate morphologically with thick and long processes; 0.1 to 0.2 mM Bt2cAMP, by itself, had no effect on cell growth and did not induce neurite outgrowth. The effect of alpha-FMO, either by itself or in combination with 0.1 to 0.2 mM Bt2cAMP, on the morphological differentiation of mouse neuroblastoma cells was reversed by the addition of exogenous putrescine or spermidine. The morphological differentiation of mouse neuroblastoma cells induced by 1 mM alpha-FMO plus 0.2 mM Bt2cAMP was accompanied by increases of the regulatory subunit of the type I cAMP-binding protein and acetylcholinesterase activity. These results indicate that the modulation of cellular polyamine contents may be important in neuroblastoma cell differentiation.
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PMID:Effects of inhibitors of ornithine decarboxylase on the differentiation of mouse neuroblastoma cells. 630 69


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