Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clonal human neuroblastoma cell line SK-N-SH-SY5Y was previously shown to express mu-opioid and alpha 2-adrenoceptors which are both negatively coupled to adenylyl cyclase. Because of the potential use of alpha 2-agonists in the treatment of narcotic dependence, we tested the interactions among he alpha 2-agonists, clonidine and norepinephrine, and morphine on AC in SH-SY5Y cells. Pretreatment with retinoic acid resulting in partial neuronal differentiation greatly enhanced the cells' sensitivity towards adenylyl cyclase stimulation by prostaglandin E1, and its inhibition by morphine and alpha 2-agonists. Norepinephrine (EC50 = 69 nM) maximally inhibited prostaglandin E1-stimulated cAMP accumulation (by approximately 83%), and the alpha 2-agonist yohimbine reversed these effects. Clonidine (EC50 = 32 nM) was a partial agonist, with 50 to 60% maximal inhibition. The combined effects of morphine (maximum approximately 70% inhibition) and norepinephrine exceeded the effect of either agent alone, yielding more than 90% inhibition of prostaglandin E1-stimulated cAMP accumulation. As previously reported for morphine, only a partial tolerance was observed for adenylyl cyclase inhibition by norepinephrine. Further, no cross-tolerance was observed between clonidine and morphine. The combined results indicate that mu-opioid receptors and an alpha 2-adrenoceptor subtype are colocalized on the same cells in SH-SY5Y culture, which hence serves as a model to study opioid-alpha 2-adrenergic interactions.
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PMID:Interaction among mu-opioid receptors and alpha 2-adrenoceptors on SH-SY5Y human neuroblastoma cells. 135 61

In SK-N-MC human neuroblastoma cells, the cAMP response to 10 nM isoproterenol (ISO) is mediated primarily by beta 1-adrenergic receptors. However, responses to higher concentrations of ISO (100-1000 nM) were only weakly blocked by beta 1- and beta 2-selective antagonists. When beta 1 receptors were blocked with 10 microM CGP 20712A, catecholamines still maximally activated cAMP accumulation, with only small decreases in potency. In the presence of CGP 20712A, beta blockers inhibited the response to ISO stereoselectively but with relatively low potencies. Pindolol derivatives were partial agonists with low potencies, and the atypical agonist BRL 37344 was a partial agonist with an intermediate potency. All binding sites in these cells labeled by 125I-cyanopindolol were of the beta 1 subtype. Nuclease protection assays indicated that SK-N-MC cells contain mRNA for both the human beta 1- and beta 3-adrenergic receptors, with the beta 3 subtype mRNA being expressed 25-50% more abundantly than that for the beta 1 subtype. Northern blot hybridizations showed the presence of two beta 3 mRNA transcripts of 3.1 and 2.4 kilobases. These results suggest that beta 1- and atypical beta-adrenergic receptors coexist in these cells and cause redundant increases in cAMP formation. Although molecular approaches suggest that the atypical subtype is the beta 3, the observed drug specificity differs from that reported for the expressed recombinant human beta 3 receptor.
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PMID:Coexisting beta 1- and atypical beta-adrenergic receptors cause redundant increases in cyclic AMP in human neuroblastoma cells. 135 96

Cyclic AMP can profoundly influence the growth and differentiation of neuronal cells in culture. In this study, the relationship between this second messenger signal transduction pathway, cell differentiation, and the expression of a retinoid-responsive, thymosin beta-10 gene was examined. Thymosin beta-10 and cognate mRNA were expressed at high levels in actively proliferating rat B104 neuroblastoma cells cultured in medium containing 10% FCS. These cells were induced to differentiate in the presence of the cAMP analog N6, 2'-O-dibutyryladenosine 3':5'-cyclic monophosphate (Bt2-cAMP) (1 mM) and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) (100 microM). Expression of thymosin beta-10 mRNA was markedly inhibited (greater than 90% and 70%, respectively) by these compounds. Addition of sodium butyrate (NaB, 1 mM) indicated that at least part of the inhibitory actions of Bt2-cAMP were due to esterase-induced release of butyrate from this compound. Adenosine (50 microM), a metabolic precursor to endogenous cyclic AMP, also inhibited accumulation of thymosin beta-10 mRNA (to less than 70% of control levels). The inhibitory action of Bt2-cAMP upon thymosin beta-10 mRNA levels was time dependent; levels were inhibited by greater than 50% 24 hours after addition of the cAMP analog and by greater than 90% after 72 hours. Serum starvation (0.2% FCS for seven days) provoked a marked increase in neurite out-growth; this morphological change was also accompanied by a modest inhibition of thymosin beta-10 mRNA accumulation. These findings together with previous observations imply that both cyclic AMP-dependent and retinoid-responsive mechanisms coordinate thymosin beta-10 gene expression during neuroembryogenesis.
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PMID:Influence of cyclic AMP and serum factors upon expression of a retinoid-responsive gene in neuroblastoma cells. 137 94

Bordetella pertussis produces a calmodulin-stimulated adenylyl cyclase that invades animal cells and raises intracellular cAMP levels [Confer, D. L., & Eaton, J. W. (1982) Science 217, 948-950; Shattuck, R. L., & Storm, D. R. (1985) Biochemistry 24, 6323-6328]. The mechanism for invasion of animal cells by this enzyme has not been defined, but there is considerable evidence that it does not enter by receptor-mediated endocytosis [Gordon, V. M., Leppla, S. H., & Hewlett, E. L. (1988) Infect. Immun. 56, 1066-1069; Donovan, M. G., & Storm, D. R. (1990) J. Cell. Physiol. 145, 444-449]. In this study, the importance of high-affinity calmodulin (CaM) binding for entry of the enzyme into neuroblastoma cells was evaluated using a mutant enzyme that has significantly lower affinity for calmodulin than the wild-type enzyme. Oligonucleotide-directed site-specific mutagenesis was used to create a point mutant at a critical tryptophan residue (Trp-242) within the proposed CaM binding domain of the B. pertussis adenylyl cyclase. Substitution of Trp-242 with Glu lowered the apparent affinity of the enzyme for calmodulin by 250-fold; however, the maximal enzyme activity in the presence of saturating calmodulin was equivalent to the wild-type enzyme. The Glu-242 mutant adenylyl cyclase was returned to B. pertussis by homologous recombination, and the enzyme produced by this strain was examined for invasion of neuroblastoma cells. Although the mutant enzyme stimulated the production of intracellular cAMP in neuroblastoma cells, the rate of cAMP accumulation was at least 10-fold lower than that caused by the wild-type enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:High-affinity calmodulin binding is required for the rapid entry of Bordetella pertussis adenylyl cyclase into neuroblastoma cells. 139 Jun 75

The regulation of human corticotropin-releasing hormone (hCRH) gene promoter activity by inducers of cAMP was investigated by transient transfection with a construct containing the hCRH gene promoter fused to the chloramphenicol acetyltransferase gene. Expression of hCRH-chloramphenicol acetyltransferase was strongly enhanced by forskolin in the neuroblastoma SK-N-MC and choriocarcinoma JAR cell lines. Overexpression of the catalytic subunit of protein kinase A dispensed the need for forskolin, and cotransfection of cAMP-responsive element-binding protein cDNAs enhanced forskolin-dependent expression of the hCRH promoter. Progressive 5'-end deletions of the hCRH promoter delineated a cAMP- responsive region between -226 and -164 base pairs. This fragment contained the sequence TGACGTCA at -221 base pairs, consistent with the consensus motif for a CRE. A homologous oligonucleotide responded to cAMP when cloned in either orientation in front of the thymidine kinase promoter. However, the level of constitutive and inductive cAMP expression was dependent on the cell line and on intrinsic properties of the promoter. Mutation of the wild type CRH-CRE sequence into an AP-1 site (TGAGTCA) completely abolished stimulation by cAMP. In contrast, coexpression of the catalytic subunit of protein kinase A dispensed the need for stimulation with forskolin, which showed that the CRH-CRE oligonucleotide served as a functional equivalent of the native CRE element.
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PMID:Identification and characterization of a 3',5'-cyclic adenosine monophosphate-responsive element in the human corticotropin-releasing hormone gene promoter. 148 Jan 79

To study how the expression of the D1A dopamine receptor gene is regulated, a human genomic clone was isolated by using a rat cDNA as probe. A 2.3-kilobase genomic fragment spanning -2571 through -236 relative to the adenosine of the first methionine codon was sequenced. The gene has an intron of 116 base pairs in the 5' noncoding region, nucleotides -599 through -484 as determined by S1 mapping and reverse transcription-PCR. It has multiple transcription initiation sites located between -1061 and -1040. The promoter region lacks a TATA box and a CAAT box, is rich in G+C content, and has multiple putative binding sites for transcription factor Sp1. Thus, the promoter region of the human D1A gene has features of "housekeeping" genes. However, it also has consensus sequences for AP1 and AP2 binding sites and a putative cAMP response element. The ability of four deletion mutants of the 2.3-kilobase fragment to modulate transcription of the heterologous chloramphenicol acetyltransferase gene in the promoterless plasmid pCAT-Basic was determined. All mutants demonstrated substantial transcriptional activity in the murine neuroblastoma cell line NS20Y, which expresses the D1A gene endogenously. Transient expression assays suggested the presence of a positive modulator between nucleotides -1340 and -1102, and a negative modulator between -1730 and -1341. The four genomic fragments had no or very low transcriptional activity in NB41A3, C6, and Hep G2 cells, which are not known to express this gene. Thus, the human D1A gene belongs to the category of tissue-specific, regulated genes that have housekeeping-type promoters.
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PMID:Characterization of the 5' flanking region of the human D1A dopamine receptor gene. 155 11

Heat shock (44 degrees C) applied for only 15 min induced the development of neurites in neuroblastoma cells 3-6 days later. During the first day after heat shock a transient increase in the rate of cytokinesis together with a synchronizing effect was observed, which led to waves of cytokinesis 14.5 h apart. Individual cell cycles were determined and showed a lengthening in the minimal cell cycle duration and a decrease in the cell cycle variance after shock. Two to 3 days after heat shock the proliferation rate decreased and then recovered. During the 6 days after heat shock, total protein synthesis was lower compared to the untreated cultures. The synthesis of heat shock proteins (100, 90, 84, 70, 68 kDa and some of lower MW) reached a maximum 6 h after heat shock. Parallel changes in the phosphorylation state of proteins were observed in an in vitro assay. Four proteins (100, 89, 67, and 15 kDa) increased and two proteins (97, 73 kDa) decreased their phosphorylation state significantly. Six days after heat shock two proteins (89, 55 kDa) increased their phosphorylation state; the 55-kDa phosphoprotein was identified as tubulin. The effect of heat shock on the intracellular calcium level was determined by measuring Fura 2 fluorescence. Six hours after shock, the Ca2+ level increased to a maximum (about three times the control value) and then dropped during the following days below the control values. We conclude from these results that a decrease in the calcium level may be causally involved in the differentiation process. The calcium effect is probably mediated by changes in the activity of different kinases. This assumption is compatible with the results of experiments with cyclic nucleotides when 10(-5) M cAMP and cGMP were added to in vitro assays of protein phosphorylation. They had different stimulating effects in heat-shocked, differentiating, and growing (control) cells.
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PMID:Effects of heat shock on neuroblastoma (N1E 115) cell proliferation and differentiation. 156 95

Muscarinic receptors in N1E 115 mouse neuroblastoma cells were characterized by competition binding experiments using three agonists and five antagonists, including 4-DAMP and AF-DX 116, and by studying the effect of agonist stimulation on the cellular cAMP and cGMP content. The results of the binding studies with the antagonists suggest that only one single homogeneous binding site of the M1 muscarinic receptor subtype is present. For the binding with the agonists, two binding sites were detected, one with high affinity for the ligand (between 53 and 77% of the total binding sites depending on the agonist) and one with low affinity. In contrast to the results obtained with the binding experiments using antagonists, the study of the cellular cyclic nucleotide response upon carbachol stimulation suggested the presence of both the M1 and M2 subtypes as there was an increase in cyclic GMP concentration while at the same time, the prostaglandin-stimulated synthesis of cyclic AMP was inhibited. Considering both binding and functional data we suggest that in N1E 115 cells a majority of M1 and a minority of M2 muscarinic receptors are present; there is no evidence for the presence of M3 muscarinic receptors.
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PMID:Study of the muscarinic receptor subtypes in N1E 115 mouse neuroblastoma cells. 164 47

Expression of the c-fos protooncogene is induced by a great variety of extracellular stimuli. A fos-lacZ fusion gene has been constructed that recapitulates this regulation. The fos-lacZ gene was introduced into B104 neuroblastoma cells for use in a quantitative assay for stimulus-transcription coupling. Both alpha- and beta-adrenergic agonists, dibutyryl cAMP, and phorbol ester induced beta-galactosidase activity in a dose-dependent manner. Thus, the interactions of receptors with agonists and antagonists, as well as intracellular second messenger-mediated signaling events, can be analyzed quantitatively. This approach represents a prototypic method for investigating stimulus-response coupling based upon gene expression.
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PMID:Regulation of a fos-lacZ fusion gene: a paradigm for quantitative analysis of stimulus-transcription coupling. 164 27

Protein kinase inhibitor H-7 and dibutyryl (dB)-cAMP were found to induce neuritic processes in mouse neuroblastoma N18TG2 cells (36). In the present study, morphological differences between the neurites induced by H-7 and those by dB-cAMP were examined using electron microscopy (TEM and SEM) and tubulin immunohistochemistry. It was observed that: 1) The neurites induced by H-7 were relatively thin and frequently had varicosities. On the other hand, the neurites induced by dB-cAMP were thick but they had few varicosities. 2) Centrioles were frequently observed in the cells treated with dB-cAMP but were not encountered in the H-7-treated cells. 3) TEM and tubulin immunohistochemistry revealed that the main shafts of the neurites induced either by H-7 or dB-cAMP were filled with microtubules, but that the varicosities induced by H-7 contained a smaller amount of microtubules. 4) The stability to colchicine was greater in the neurites induced by H-7 than in those by dB-cAMP. From these features of the neurites, it was inferred that neurite outgrowth induced by dB-cAMP is deeply related to the formation of microtubules and that the neurites induced by H-7 were involved in other processes probably including an adhesive property of cell surfaces.
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PMID:Morphology of neurites from N18TG2 cell induced by protein kinase inhibitor H-7 and by cAMP. 165 Nov 49


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