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)

SK-N-MC cells, derived from a human neuroblastoma, respond to endothelin (ET) peptides with an increase in the free intracellular calcium concentration. The response is biphasic, with the secondary plateau phase being abolished or reduced by removal of extracellular Ca2+ or by the presence of 100nM nitrendipine. Restoration of Ca2+ to the bathing solution in cells stimulated by ET-1 in the absence of Ca2+ caused the plateau to reappear. The order of potency of ET family peptides was ET-2 greater than or equal to sarafotoxin S6b greater than or equal to ET-1 much greater than ET-3, suggesting that ETA receptors mediate the response. Sarafotoxin S6c and the C-terminal hexapeptide endothelin (16-21) were inactive in these cells. [Ala1,3,11,15]ET-1, a linear analogue of ET-1 which has been suggested to be a selective ETB receptor agonist, was a weak competitive antagonist of the actions of ET-1 in these cells. However, BQ-123, recently introduced as a selective and competitive antagonist at ETA receptors, was a potent non-competitive antagonist of ET-1 giving a 50% reduction in the maximum response at 6nM.
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PMID:BQ-123, cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu), is a non-competitive antagonist of the actions of endothelin-1 in SK-N-MC human neuroblastoma cells. 156 52

We have previously reported that endothelin (RT) receptor activation increases intracellular calcium concentrations ([Ca2+]i) in NG108-15 cells, a hybrid of rat glioma C6-BU-1 and mouse neuroblastoma N18TG2 cells. This study was designed to further explore the origin of the ET receptor and [Ca2+]i mobilization in the parent cell lines hybridized to form the NG108-15 cells. [125I]ET-1 bound to a single class of high affinity sites in C6-BU-1 cells with a KD value of 108pM and Bmax of 12,400 sites/cell. ET-1, ET-2, ET-3 and big ET inhibited [125I]ET-1 binding to C6-BU-1 cells with KD values of 0.074, 0.167, 261 and 187 nM, respectively. All ETs produced a rapid increase in [Ca2+]i in C6-Bu-1 cells. EC50 values for ET-1, ET-2, ET-3 and big ET were 0.71, 1.14, 120 and 243 nM respectively. There was a significant correlation between the KD values obtained from competition binding experiments and the EC50 values from [Ca2+]i response curves in C6-BU-1 cells (r = 0.996, p less than 0.004). Ten nM ET-1 produced about 85% of the maximal [Ca2+]i increase in C6-BU-1 cells which was reduced by 96% in the absence of extracellular calcium. Furthermore, diltiazem (10 microM) and nifedipine (1 microM) failed to block ET-induced [Ca2+]i mobilization. None of the ETs elevated [Ca2+]i or displayed any specific [125I]ET-1 binding in N18TG2 cells. These data suggest that ET binds to a specific ET receptor in C6-BU-1 cells, and elevates [Ca2+]i through dihydropyridine-insensitive, receptor-mediated calcium influx. Further, the ability of ETs to elevate [Ca2+]i in NG108-15 hybrid cells is due to the ET receptor inherent to the C6-BU-1 glioma parent line.
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PMID:Comparison of endothelin binding and calcium mobilization in C6-BU-1 rat glioma and N18TG2 mouse neuroblastoma cells. 165 31

1. Specific binding sites for synthetic endothelin (ET) isoforms were studied on intact cells of the SK-N-MC cell line, derived from a human neuroblastoma. 2. [125I]-ET-1 (2.5 x 10(-11) M) specifically bound to a single class of binding sites on these cells (Hill coefficient of 1.06 +/- 0.04, n = 3) with an apparent Kd of 1.4 +/- 0.3 x 10(-9) M and a Bmax of 3.1 +/- 1.0 pmol mg-1 protein. [125I]-ET-3 (2.5 x 10(-11) M), did not specifically bind to SK-N-MC cells. 3. The binding of [125I]-ET-1 was competitively inhibited by other ET isoforms, the order of potency being ET-1 greater than sarafotoxin S6b greater than ET-3. 4. Association of 1 nM [125I]-ET-1 at 37 degrees C reached apparent equilibrium at 60-80 min, with half-maximal binding being achieved at 12 min. 5. Dissociation was measured after both 10 min and 60 min of association with 64% and 30% respectively of specifically bound [125I]-ET-1 dissociating. The actual amounts of [125I]-ET-1 dissociated were similar in both cases. 6. Incubation of [125I]-ET-3 with SK-N-MC cells at 37 degrees C for 60 min did not result in significant degradation of this peptide. However, [125I]-ET-1 was broken down by incubation with SK-N-MC cells, the pattern of degradation of dissociable [125I]-ET-1 (and that found in the supernatant) being different from that of non-dissociable [125I]-ET-1. 7. ET-1 concentration-dependently induced an increase in total inositol phosphate accumulation in subconfluent (but not in confluent) cultures of SK-N-MC cells (EC50 = 6.43 +/- 1.9 x 1010M). ET-3 was without effect. 8. These results show that ET-1 specifically binds to SK-N-MC cells with the characteristics of an ETA receptor. Our earlier finding that adrenal chromaffin cells express an ETB receptor indicates the existence of multiple ET receptor types on neuronal cells.
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PMID:Characterization of endothelin receptors on a human neuroblastoma cell line: evidence for the ETA subtype. 166 49

The effects of endothelin(ET)-1, ET-2, ET-3 and Big ET on intracellular level of Ca2+ ([Ca2+]i) were studied in neuroblastoma NG108-15 and NCB-20 cells. All ETs, except Big ET, induced an increase in [CA2+]i in NG108-15 cells in a dose-dependent manner, with EC50: 6.7, 11.2 and 71 nM, respectively. However, none of the ET increased [Ca2+]i in NCB-20 cells. Calcium channel blockers diltiazem or nicardipine had no effect on ET-induced increase in [CA2+]i, but extracellular Ca2(+)-depletion significantly reduced the response of NG108-15 cells to ETs. NG108-15 cells exhibited a homologous desensitization to sequential addition of ETs, but no heterologous desensitization among ET, bradykinin and PAF was observed. These data suggest that ET-induced receptor activation results in increased intracellular Ca2+ via a non voltage calcium channel mechanism and intracellular Ca2+ release.
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PMID:Effect of endothelins on cytosolic free calcium concentration in neuroblastoma NG108-15 and NCB-20 cells. 227 19

Addition of endothelins (ETs) to neuroblastoma-glioma hybrid cells (NG108-15) induced increases in cytosolic free Ca2+ ([Ca2+]i) levels of labeled inositol monophosphates and inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. The increases in [Ca2+]i elicited by the three ETs (ET-1, ET-2, and ET-3) were transient and did not show a sustained phase. Chelating extracellular Ca2+ in the medium by adding excess EGTA decreased the ET-mediated Ca2+ response by 40-50%. This result indicates that a substantial portion of the increase in [Ca2+]i was due to influx from an extracellular source. However, the increase in [Ca2+]i was not affected by verapamil or nifedipine (10(-5) M). A rank order potency of ET-1 > ET-2 > ET-3 is shown for the stimulated increase in [Ca2+]i, as well as labeled inositol phosphates, in these cells. ATP (10(-4) M) and bradykinin (10(-7) M) also induced the increases in [Ca2+]i and Ins(1,4,5)P3 in NG108-15 cells, albeit to a different extent. When compared at 10(-7) M, bradykinin elicited a five- to sixfold higher increase in the level of Ins(1,4,5)P3, but less than a twofold higher increase in [Ca2+]i than those induced by ET-1. Additive increases in both Ins(1,4,5)P3 and [Ca2+]i were observed when ET-1, ATP, and bradykinin were added to the cells in different combinations, suggesting that each receptor agonist is responsible for the hydrolysis of a pool of polyphosphoinositide within the membrane. ET-1 exhibited homologous desensitization of the Ca2+ response, but partial heterologous desensitization to the Ca2+ response elicited by ATP. On the contrary, ET-1 did not desensitize the response elicited by bradykinin, although bradykinin exhibited complete heterologous desensitization to the response elicited by ET-1. Taken together, these results illustrate that, in NG108-15 cells, a considerable amount of receptor cross talk occurs between ET and other receptors that transmit signals through the polyphosphoinositide pathway.
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PMID:Endothelin-mediated calcium response and inositol 1,4,5-trisphosphate release in neuroblastoma-glioma hybrid cells (NG108-15): cross talk with ATP and bradykinin. 838 Apr 32

The endothelin (ET) peptides have been identified in the CNS, but there is a paucity of information on their physiological roles. NG108-15 cells, a clonal strain of a neuroblastoma x glioma hybrid cell line, have been widely used in neurobiological research since they retain certain differentiated properties of the non-transformed parental cells. It is known that NG108-15 cells respond to the ET peptides, but only limited information is available on the characterization of the ET receptors that mediate these effects. The present study was designed to identify the type(s) of ET receptors on NG108-15 cells in a proliferative state by competitive binding assays using [125I]ET-1 as the radiolabelled ligand and the receptor-selective ligands. ET-1, ET-3, BQ-123, sarafatoxin-6-c and [Ala1,3,11,15]ET-1. The results suggested the presence of conventional ETA and ETB receptor subtypes, with ETA in excess over ETB. These findings were consistent with the results of Northern analysis in that mRNAs encoding the ETA and ETB receptor subtypes were identified in NG108-15 cells, with a preponderance of ETA to ETB. Of considerable interest was the observation of other ET-binding components with much higher affinities than the conventional receptors. It remains to be demonstrated if these particular binding components are functional and represent differ gene products or arise from association of the conventional ETA and ETB receptor subtypes with themselves or other structures, e.g. proteins or lipids, of CNS origin.
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PMID:Endothelin binding to NG108-15 cells: evidence for conventional ETA and ETB receptor subtypes and super-high affinity binding components. 899 27

The endothelin (ET) peptides, ET-1, ET-2, and ET-3, as well as the ETA and ETB receptor subtypes, are known to occur in brain, but there is a dearth of information on the metabolism of these peptides by the central nervous system (CNS). In this study we have investigated the kinetics of ET-1 binding to and dissociation from the hybrid neuroblastoma x glioma cell line, NG108-15, which is known to contain functional ET receptors, and metabolism of bound ET-1. [125I]ET-1 was incubated with cells for various periods of time up to 6 h, and the nature of the radioactivity in the cell medium and lysate was analyzed by reverse phase high performance liquid chromatography (HPLC). It was found that NG108-15 cells are capable of degrading [125I]ET-1 to [125I]Tyr and several fragments of intermediate hydrophobicity; however, a portion of the cell-associated [125I]ET-1 was protected from degradation for several hours.
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PMID:Metabolism of endothelin-1 by neuroblastoma x glioma hybrid (NG108-15) cells. 914 3

Despite significant advances in understanding the genetic background in Hirschsprung's disease (HD), the majority of cases are believed to be multigenic and multifactorial. Conditions associated with an increased risk of HD suggest some common inherited factor and include Down's syndrome, Waardenburg syndrome (WS), dominant sensorineural deafness, neurofibromatosis, neuroblastoma, phaechromocytoma, the MEN type 2B syndrome, and other abnormalities. The reported incidence of Down's syndrome in HD is approximately 2%, but the range varies from 2% to 15%. WS, on the other hand, is one of a number of uncommon human conditions in which pigmentary disturbances are associated with sensorineural deafness. HD mutations have been mapped to a number of genes, i.e., RET proto-oncogene, at 10q11.2; the recessive EDNRB gene, located at 13q22; its ligand endothelin 3 (EDN3); and the glial cell line-derived neurotrophic factor (GDNF) in humans. Mutations of known genes appear to account for only a relatively small number of HD cases (20% in the case of RET). GDNF may modulate the disease phenotype by interacting with other susceptibility loci (e.g., RET). The genetic aspects of HD occurring in association with trisomy 21 and WS are reviewed. Clinical presentation, diagnosis, treatment and long-term outcome in this patient group are evaluated. Additional data are presented on 12 children with Down's syndrome out of 408 surgically treated HD patients. The role of associated anomalies is evaluated, and an increased susceptibility to severe enterocolitis associated with a high mortality rate is reported. Surgical correction can be achieved, but patients may require some form of ongoing help to facilitate acceptable bowel function. The decision as to the nature and timing of the surgical correction must be individualized.
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PMID:Hirschsprung's disease: genetic and functional associations of Down's and Waardenburg syndromes. 971 53

The mechanism underlying endothelin-1 (ET-1)-induced increases in intracellular Ca2+ concentrations in the human neuroblastoma cell-line SK-N-MC was investigated. ET-receptor agonists increased inositol phosphate (IP)-formation (assessed as accumulation of total [3H]-IPs in [3H]-myo-inositol prelabelled cells) and intracellular Ca2+ (assessed by the FURA-2 method) with an order of potency: ET-1 > sarafotoxin 6b (S6b)> ET-3 = S6c; the ETA-receptor antagonist BQ-123 inhibited both responses with apparent pKi-values of 8.3 and 8.6, respectively, while the ETB-receptor antagonist BQ-788 did not. Pretreatment of the cells with pertussis toxin (PTX, 500 ng ml(-1) overnight) reduced ET-1-induced Ca2+ increases by 46+/-5%, but rather enhanced ET-1-induced IP-formation. Chelation of extracellular Ca2+ by 5 mM EGTA did not affect ET-1-induced IP-formation. However, in the presence of 5 mM EGTA or SKF 96365, an inhibitor of receptor mediated Ca2+ influx (1.0-3.0 x 10(-5) M) ET-1-induced Ca2+ increases were inhibited in normal, but not in PTX-treated cells. [125I]-ET-1 binding studies as well as mRNA expression studies (by RT-PCR) detected only ETA-receptors whereas expression of ETB-receptor mRNA was marginal. ET-1 (10(-8) M) inhibited isoprenaline-evoked cyclic AMP increases; this was antagonized by BQ-123, not affected by BQ-788 and abolished by PTX-treatment. We conclude that SK-N-MC cells contain a homogeneous population of ETA-receptors that couple to IP-formation and inhibition of cyclic AMP formation. Stimulation of these ETA-receptors increases intracellular Ca2+ by at least two mechanisms: a PTX-insensitive IP-mediated Ca2+ mobilization from intracellular stores and a PTX-sensitive influx of extracellular Ca2+.
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PMID:Mechanism of ET(A)-receptor stimulation-induced increases in intracellular Ca2+ in SK-N-MC cells. 986 48

The study reported here characterizes the presence both of endothelin (ET) receptors and of a synthesizing ET apparatus in the human neuroblastoma SK-SY5Y cell line. We demonstrated, using reverse transcriptase polymerase chain reaction (RT-PCR), that these cells bound [125I]ET-1. The potency order of ET analogs to inhibit [125I]ET-1 binding was consistent with the presence of ET(A)-receptors. [Ca2+]i was increased by both ET-1 and ET-3 (potency order: ET-1 > ET-3. The mRNAs of preproendothelin-1 and of endothelin converting enzyme (ECE) were expressed by cells, as shown by RT-PCR studies. These mRNAs were translated into functional proteins as the cells were able to release mature (1-21) ET-like immunoreactivity into the culture medium. That secretion was time-dependent and was enhanced by treatment of the cells by the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate. These results show that the human SK-SY5Y neuroblastoma cell line produces mature ET which could act as an autocrine/paracrine factor these cells.
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PMID:The human neuroblastoma SK-SY5Y cell line bears functional endothelin-A-receptors and endothelin. 1107 38


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