Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 high-affinity binding of benzomorphan drugs (ethylketocyclazocine and N-allylnorcyclazocine) and [DAla2,DLeu5] enkephalin was examined in a mouse neuroblastoma--Chinese hamster brain clonal hybrid cell line (NCB-20). Scatchard analysis of saturation binding isotherms indicated the presence of a single binding site for 3H-labeled [DAla2,DLeu5]enkephalin (Kd = 3 nM) and multiple binding sites for [3H]ethylketocyclazocine (Kd = 4 and 20 nM) and N-[3H]allylnorcyclazocine (Kd = 0.5 and 15 nM). Both ethylketocyclazocine and N-allylnorcyclazocine competed (Ki = 10 and 30 nM, respectively) with [3H][DAla2,DLeu5]enkephalin binding in NCB-20 cells but neither [DAla2,DLeu5]enkephalin nor morphine could completely inhibit the specific binding of [3H]ethylketocyclazocine (7 nM) or N-[3H]allylnorcyclazocine (3 nM). Furthermore, not all benzomorphan drugs (e.g., ethylketocyclazocine) were totally efficacious in displacing 3 nM N-[3H]allylnorcyclazocine binding in the presence or absence of high concentrations of [DAla2,DLeu5]enkephalin. The data presented suggest that benzomorphan drugs interact with three distinct high-affinity binding sites: (i) a site that binds enkephalin and morphine in addition to ethylketocyclazocine and N-allylnorcyclazocine; (ii) a site that binds both ethylketocyclazocine and N-allylnorcyclazocine but not enkephalin and morphine; and (iii) a site that binds N-allylnorcyclazocine but not enkephalin, morphine, or ethylketocyclazocine. The first of these sites was comparable to the delta opiate receptor expressed in NG108-15 and N4TG1 cell lines based on the potency series obtained for various opiates and benzomorphan drugs in competition studies with [3H][DAla2,DLeu5]-enkephalin. However, the specific high-affinity benzomorphan binding sites thus far are unique and may represent biochemical correlates of kappa and sigma opiate receptors which have been proposed to exist on the basis of physiological studies.
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PMID:Distinct high-affinity binding sites for benzomorphan drugs and enkephalin in a neuroblastoma--brain hybrid cell line. 611 74

Nine new compounds have been synthesized as potential affinity ligands for specific opioid receptors. The biochemical properties of three of these compounds were examined in detail and one of them, N-cyclopropylmethyl-7 alpha-methylfumaroylamido-6, 14-endoethenotetrahydronororipavine (NIH 10236), was found to be a potent irreversible ligand for the delta opioid receptor. It had the properties of a narcotic antagonist, as determined by its effect on adenylate cyclase activity of NG108-15 neuroblastoma-glioma cell homogenates. It is, thus, the first delta specific alkylating ligand known which is a narcotic antagonist. A second compound, the N-cyclopropylmethyl-7 alpha-isothiocyanato-6, 14-endoethenotetrahydronororipavine (NIH 10235) was found to be a mu specific alkylating ligand in brain and a reversible antagonist in the NG108-15 cells.
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PMID:Probes for narcotic receptor mediated phenomena. 5. Narcotic antagonist irreversible ligands based on endoethenotetrahydrooripavine. 631 54

Ethylketocyclazocine (EKC) binds to two sites on NCB-20 neuroblastoma X Chinese hamster brain hybrid cells (KDH = 2 nM, Bmax = 21,000 sites/cell; KDL = 27 nM, Bmax = 140,000 sites/cell. The high-affinity site has been characterized as a delta opiate receptor. The low-affinity site is relatively benzomorphan-specific; opioid peptides, morphine, etorphine, and naloxone do not compete at it. Rank order of potency among benzomorphans is (+)-EKC greater than Mr 2267 greater than (+)-ketocyclazocine greater than (+)-SKF 10047 greater than bremazocine greater than cyclazocine. Among other drugs of interest that inhibit [3H]EKC binding are phencyclidine and its analogues, Ki values for which are 0.2-40 microM. Stereoselectivity is the reverse of other opioid receptors: (+)-EKC much much greater than (-)-EKC, Mr 2267 greater than Mr 2266, (+)-SKF 10047 greater than (-)-SKF 10047. The site is sensitive to trypsin, but not to N-ethylmaleimide. Binding is insensitive to nucleotides, slightly sensitive to physiological concentrations of sodium, magnesium, and manganese ions and to EDTA but not EGTA.
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PMID:[3H]ethylketocyclazocine binding to NCB-20 hybrid neurotumor cells. 633 80

Neuroblastoma x glioma hybrid, NG108-15, cells appear to express the alpha-subunit of the guanine nucleotide-binding protein Gs in a substantial molar excess over its effector adenylate cyclase [Kim, Adie and Milligan (1994) Eur. J. Biochem. 219, 135-143]. Addition of the IP prostanoid receptor agonist iloprost to intact NG108-15 cells resulted in a dose-dependent increase in formation of the complex between Gs alpha and adenylate cyclase (GSAC) as measured by specific high-affinity binding of [3H]forskolin. NG108-15 cells transfected to express either relatively high (clone beta N22) or low (clone beta N17) levels of beta 2-adrenoceptor both showed dose-dependent increases in specific [3H]forskolin binding in response to the beta-adrenoceptor agonist isoprenaline, and maximally effective concentrations of isoprenaline resulted in the generation of similar numbers of GSAC complexes in both clones. The dose-effect curve for clone beta N22, however, was some 15-fold to the left of that for clone beta N17, which is similar to that noted for isoprenaline-mediated stimulation of adenylate cyclase activity [Adie and Milligan (1994) Biochem. J. 303, 803-808]. In contrast, dose-effect curves for iloprost stimulation of [3H]forskolin binding were not different in clones beta N22 and beta N17. Basal specific [3H]forskolin binding in the absence of agonist was significantly greater in cells of clone beta N22 than clone beta N17. This was not a reflection of higher immunological levels of adenylate cyclase, indicating that the higher basal formation of GSAC probably reflects empty-receptor activation of Gs. This higher basal specific [3H]forskolin binding was partially reversed by propranolol. The addition of the opioid peptide D-Ala-D-Leu-enkephalin to NG108-15 cells did not reduce iloprost-stimulated [3H]forskolin binding even though this peptide inhibits stimulated adenylate cyclase activity by activation of a delta opioid receptor.
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PMID:Detection and analysis of agonist-induced formation of the complex of the stimulatory guanine nucleotide-binding protein with adenylate cyclase in intact wild-type and beta 2-adrenoceptor-expressing NG108-15 cells. 753 56

Phosphodiester antisense oligodeoxynucleotides (ODNs) directed against various domains of the cloned mouse delta receptor DOR-1 reduce delta-opioid receptor binding in vivo and in vitro. The present study examines the stability of an antisense ODN (275 nM) directed against the delta-opioid receptor and its effect on DOR-1 mRNA in cultured neuroblastoma cells and in vivo. When added to NG108-15 cells, much of the antisense ODN is degraded. However, > 1% is intact, associated with cells, and stable for at least 72 h. Northern blot analysis demonstrates that treatment of NG108-15 cells with the antisense ODN reduces the levels of a species of DOR-1 mRNA by approximately 25%. Similarly, intrathecal administration of the antisense ODN results in the accumulation of intact ODN within the spinal cord, which is stable for at least 72 h, although the levels of accumulation in vivo are lower than in vitro after either 4 or 72 h. Antisense ODN treatment lowers DOR-1 mRNA levels by approximately 25%. The loss of mRNA both in vivo and in vitro corresponds quite well to the decreases in receptor binding previously observed by our laboratory and is consistent with reduction of delta-opioid receptor protein in vitro as determined by western blot with a monoclonal antibody selective for the delta-opioid receptor. In conclusion, these studies indicate that a small, but significant, proportion of ODN is taken up by cells and remains intact for up to 72 h. This appears to be sufficient to down-regulate mRNA levels of delta-opioid receptors and their expression.
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PMID:Antisense oligodeoxynucleotides to the cloned delta receptor DOR-1: uptake, stability, and regulation of gene expression. 759 81

Neuroblastoma NS20Y cells possess a high density of stereoselective delta opioid receptors as determined by competition binding with 3H-diprenorphine and various opioid ligands. Scatchard analysis of [3H]diprenorphine saturation binding data revealed a Kd = 0.79 +/- 0.17 nM and Bmax = 370 +/- 50 fmol/mg protein. These opioid binding sites have highest affinity for delta opioid receptor selective agonists and lowest affinity for mu opioid receptor selective agonists. Agonist binding was sensitive to the presence of the monovalent cation, Na+. Activation of receptor with D-Ala2, D-Leu5-enkephalin (DADLE) resulted in dose-dependent inhibition of forskolin-stimulated intracellular [3H]cAMP accumulation, which was antagonized by (-)-naloxone but not (+)-naloxone. Relative potencies of various opioid agonists to inhibit intracellular cAMP production paralleled those observed in neuroblastoma x glioma NG108-15 hybrid cells. Pretreatment of NS20Y cells with pertussis toxin (PTX) eliminated opioid agonist inhibition of adenylyl cyclase activity. Chronic DADLE treatment resulted in desensitization and down-regulation of opioid receptor. An increase in intracellular [3H]cAMP level above the control was observed in the presence of naloxone after chronic DADLE treatment. Therefore, opioid binding sites in neuroblastoma NS20Y cells possess properties of the classical delta opioid receptor type. After neuroblastoma NS20Y was growth arrested by culturing the cells in serum-free medium for 72 hr, proliferation was reinitiated by addition of fetal calf serum (FCS), 0.01% to 12%, and was monitored by either [3H]thymidine incorporation or by dye viability assay. It was demonstrated that naloxone and naltriben but not Met5-enkephalin could attenuate FCS-induced proliferation in a dose-dependent manner. Naltriben was 54-fold more potent than naloxone to attenuate NS20Y proliferation. The maximal level of viable cells per well was reduced (35.2 +/- 1.9%) with no alteration in FCS concentration-dependent stimulation of growth. Similar inhibition by naloxone (37.3 +/- 2.7%) was observed with [3H]thymidine incorporation studies. This naloxone effect was serum concentration-dependent and could be blocked by culturing NS20Y cells in the presence of both naloxone and Met5-enkephalin. Although pretreatment of NS20Y cells with pertussis toxin could attenuate FCS-stimulated proliferation, naloxone effect on growth was not affected by pertussis toxin pretreatment. Furthermore, the naloxone effect was not NS20Y specific. A similar naloxone effect was observed with neuroblastoma N1E115, although not with neuroblastoma x glioma NG108-15, nor human neuroblastoma SHSY5Y, cell lines that have been reported to contain delta opioid receptors. Therefore, activation of delta opioid receptor could modulate FCS-induced growth in some but not all neuroblastoma cell lines.
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PMID:Properties of delta opioid receptor in neuroblastoma NS20Y: receptor activation and neuroblastoma proliferation. 781 47

Mu and delta opiate receptor regulation by opiate agonists and antagonists was studied in the human neuroblastoma cell line SH-SY5Y. Morphine down-regulated both mu and delta receptors, but its effects on each subtype could be dissociated by use of specific antagonists. The selective mu antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Pen-Thr-NH2 (CTAP) blocked the down-regulation of mu, but not delta receptors. Conversely, the delta antagonist (N,N-diallyl-Tyr-Aib-Aib-Phe-Leu-OH([N,N-diallyl-Tyr1, Aib2,3]Leu- enkephalin)] ICI 174,864 blocked morphine-induced down-regulation of delta but not mu receptors. These selective antagonists also were studied alone for their effects on both receptors. CTAP alone at doses of 0.1 microM and higher up-regulated mu receptors. CTAP did not affect delta receptors at 0.3 microM or less, but it down-regulated them at doses of 1 microM or more, apparently due to its delta agonist activity at higher doses, which was reversed by ICI 174,864. ICI 174,864 alone also showed complex effects on the two subtypes, up-regulating both mu and delta sites. Its effects were most selective at a low dose (0.1 microM), which upregulated delta sites with minimal effects on mu sites. The nonselective antagonist naloxone provided a more robust upregulation (> 40%) of both mu and delta receptors than either selective antagonist alone or in combination. The mu-to-delta ratio (1.4 to 1) was not altered by differentiation of the cells with retinoic acid, which up-regulated both mu and delta receptors. Differentiation with the phorbol agent 12-O-tetradecanoyl-phorbol-13-acetate, however, up-regulated mu, but not delta receptors. The selective mu agonist Tyr-Pro-MePhe-D-Pro-NH2 (PL017) down-regulated mu receptors with a half-maximal effect at 180 nM, but was without effect on delta receptors at concentrations up to 10 microM. Conversely, the selective delta agonist Tyr-D-Pen-Gly-Phe-D-Pen([D-Pen2,5]-enkephalin) (DPDPE) potently down-regulated delta receptors, producing half-maximal decreases at 0.5 nM. At doses above those that reduced the maximum binding of [3H]pCl-DPDPE binding to the delta site, DPDPE also induced an apparent loss of affinity (increased Kd) at the delta site. It was without effect on mu receptors, however, at doses up to 10 microM. Thus, down-regulation of mu and delta receptors was homologous, because selective agonists down-regulated their respective receptors without effect on the heterologous opiate receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Differential regulation of mu and delta opiate receptors by morphine, selective agonists and antagonists and differentiating agents in SH-SY5Y human neuroblastoma cells. 793 56

Both mu and delta opioid receptors are expressed in undifferentiated human neuroblastoma SHSY5Y cells and are negatively coupled to adenylate cyclase. The ability of various mu opioid, delta opioid and alpha-2 adrenergic agonists to inhibit acutely forskolin-stimulated adenylate cyclase activity in undifferentiated SHSY5Y cells after chronic administration with the selective mu opioid agonist [N-MePhe3,D-Pro4]morphiceptin (PLO17) or delta opioid agonist, [D-Pen2,D-Pen5]enkephalin (DPDPE) was assessed. In control cells, both PLO17 and DPDPE inhibited cyclic AMP (cAMP) formation with equal maximal inhibition, i.e., 60 +/- 3 and 66 +/- 2%, having IC50 values of 51.1 +/- 1.3 and 3.7 +/- 1.0 nM, respectively. The inhibition of intracellular cAMP formation by both agonists could be blocked by pertussis toxin pretreatment. After 24 hr of chronic administration of PLO17 (50 nM to 10 microM), a concentration-dependent loss of the ability of mu opioid agonists PLO17 and DAMGO, but not the delta opioid agonists DPDPE, nor alpha-2 adrenergic agonist UK-14304 (5-Bromo-N-(4,5,-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine) to inhibit adenylate cyclase activity was observed. In contrast, chronic administration of DPDPE (0.1 nM to 0.3 microM) resulted in a concentration-dependent reduction in the inhibition of cAMP formation produced by delta opioid agonists DPDPE and DSLET, but not mu opioid, nor alpha-2 adrenergic agonists tested. The observed homologous desensitization was also time-dependent. In addition, antagonist-induced increases in adenylate cyclase activity were observed only after chronic PLO17 administration.2+ Finally, chronic pretreatment of cells with PLO17 (10 microM) resulted in a significant decrease in mu opioid, but not delta opioid receptor, binding, whereas treatment with DPDPE (0.3 microM) resulted in a significant decrease in delta opioid, but not mu opioid receptor binding. Therefore, undifferentiated SHSY5Y cells may provide an excellent model system to study not only the signal transduction mechanisms of mu and/or delta opioid receptors, but also the cellular adaptations of specific opioid receptors.
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PMID:Mu and delta opioid receptor desensitization in undifferentiated human neuroblastoma SHSY5Y cells. 803 14

The delta opioid receptor has been purified, in an active form, by succinylmorphine affinity chromatography. The receptor was purified partially from bovine frontal cortex and to apparent homogeneity from neuroblastoma x glioma hybrid NG108-15 cells as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining. Antiserum to the purified bovine receptor inhibited ligand binding to membranes and immunoprecipitated a 58 kDa protein from NG108-15 cells. Reconstitution of the receptor with lipids enhanced binding by 9-fold. The 58 kDa band protein after electroelution and reconstitution with lipids also showed specific binding, indicating that the receptor could be renatured even after SDS-PAGE in an appropriate lipid environment.
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PMID:Purification and reconstitution of the delta opioid receptor. 839 46

The delta opiate receptor gene has been cloned from the mouse neuroblastoma-rat glioma hybrid cell NG108-15. The clone that we isolated is apparently identical to that reported by Evans et al. [Evans, C. J., Keith, D. E., Jr., Morrison, H., Magendzo, K. & Edwards, R. H. (1992) Science 258, 1952-1955] and essentially identical with that of Kieffer et al. [Kieffer, B. L., Befort, K., Gaveriaux-Ruff, C. & Hirth, C. G. (1992) Proc. Natl. Acad. Sci. USA 89, 12048-12052]. We have found full-length transcripts of the gene in mouse brain but in no other tissues examined. Within the brain the gene is expressed at low levels in many regions but transcripts are found in particularly large amounts in the anterior pituitary and pineal glands. Since these tissues are located outside the blood-brain barrier, opioid peptides easily can reach receptors in these areas from the blood. The gene, which is present as a single copy, has been mapped to the distal region of mouse Chromosome 4.
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PMID:Regional expression and chromosomal localization of the delta opiate receptor gene. 841 97


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