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)

N-(4-hydroxyphenyl)retinamide (HPR) is a synthetic retinoid with anti-cancer properties and lower toxicity than all-trans retinoic acid (RA). Neuroblastoma cells treated with HPR and observed by fluorescence microscopy showed clear signs of apoptosis, such as chromatin condensation and margination, nuclear fragmentation and the presence of "apoptotic bodies". Moreover, measurements on a cell-by-cell basis by the flow-cytometric DNA-content in situ-terminal-deoxinucleotidyl-transferase(TDT) assay showed that apoptosis induced by HPR was dose- and time-dependent and that the fraction of apoptotic cells increased from approximately 15% at 1.25 microM at 2 days after treatment up to approximately 90% at 5 microM and 8 days of continuous treatment. Additionally, we found that cells were induced into apoptosis independently from the cell-cycle phase. In contrast, equimolar or higher doses of RA, from 5 microM to 80 microM, were able to inhibit growth by differentiation, but failed to induce apoptosis. We conclude that the functional effects of HPR and RA in LA-N-5 neuroblastoma cells are mediated by apoptosis and differentiation respectively, suggesting a potential clinical use of HPR in the management of neuroblastoma patients.
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PMID:Neuroblastoma cell apoptosis induced by the synthetic retinoid N-(4-hydroxyphenyl)retinamide. 792 52

This review will summarize the rationale for pursuing investigations into the use of retinoids for pediatric patients with cancer, describe the phase I results of all-trans-retinoic acid (ATRA) in children, and discuss the results of a series of preclinical and clinical pharmacokinetic studies of ATRA. The prognosis for children with advanced stage neuroblastoma, the most common extracranial solid tumor of childhood, has remained poor despite significant increases in the intensity of multi-modality therapy. Observations that neuroblastoma has the potential in vivo to differentiate into the more mature neuronal phenotype of a ganglioneuroma or to spontaneously regress, combined with the ability of ATRA to induce differentiation of neuroblastoma cell lines in vitro, suggests that neuroblastoma may be a prime candidate for a retinoid-based approach to differentiation therapy. We previously performed a standard pediatric phase I trial of ATRA and defined the maximum tolerated dose (MTD) in children to be 60 mg/m2/day, significantly lower than the MTD in adult patients. Pharmacokinetic results revealed that the plasma half-life of ATRA was short (45 min) relative to 13-cis-RA (12-24 h), and that plasma drug exposure decreased significantly by day 28 of daily drug administration. Preclinical studies using an i.v. formulation of ATRA in a Rhesus monkey pharmacokinetic model then demonstrated that ATRA is eliminated by a capacity-limited (saturable) process. This elimination process was rapidly induced within the first week of daily i.v. ATRA administration, and suggested that an intermittent schedule of drug administration might allow for down-regulation of the elimination process. These pre-clinical studies formed the basis for investigating whether an intermittent schedule of ATRA administration would allow for repeated periods of relatively higher plasma drug concentrations. Preliminary results of two clinical trials using intermittent schedules of administration suggest that this approach may result in significantly higher plasma drug exposure over time. Plans to study the role of intermittent schedules of ATRA administration in pediatric phase II trials in patients with neuroblastoma are underway.
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PMID:Clinical and pharmacokinetic studies of all-trans-retinoic acid in pediatric patients with cancer. 796 27

The objective of this study was to compare the properties of 9-cis and all-trans retinoic acid with respect to the induction of expression of retinoic acid receptor beta (RAR-beta) and cellular retinoic acid-binding protein (CRABP) II in human neuroblastoma SH SY 5Y cells. RAR-beta and CRABP II mRNA was induced by both all-trans and 9-cis retinoic acid in SH SY 5Y cells. Induction was rapid, detectable within 2-4 h, and inhibited by actinomycin D. Time-courses of induction for RAR-beta and CRABP II differed: RAR-beta mRNA levels reached a maximum 4-6 h after adding all-trans or 9-cis retinoic acid, whereas CRABP II mRNA levels increased over at least 18 h. These differences were attributed to the longer half-life of CRABP II mRNA (20 h) compared with RAR-beta mRNA (3.9 h). The dose-response characteristics of all-trans and 9-cis retinoic acid were different: all-trans was effective at nanomolar concentrations, whereas 10-fold higher levels of 9-cis retinoic acid were required to achieve comparable induction of RAR-beta and CRABP II. Conversely, at high concentrations, 9-cis retinoic acid gave a greater induction of RAR-beta and CRABP II than all-trans. The induction of RAR-beta and CRABP II by all-trans retinoic acid was maintained in the subsequent absence of all-trans retinoic acid, whereas induction by 9-cis retinoic acid was dependent on its continued presence in the culture medium. These results suggest that, at high concentrations, 9-cis retinoic acid may produce its transcriptional effects via retinoid X receptor (RXR) homodimers. This has implications for the cellular functions of 9-cis retinoic acid and its use as a biological response modifier.
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PMID:Differential effects of 9-cis and all-trans retinoic acid on the induction of retinoic acid receptor-beta and cellular retinoic acid-binding protein II in human neuroblastoma cells. 799 26

Human neuroblastoma (NB) cell lines treated with all-trans retinoic acid (RA) differentiate in culture, forming neurites and exhibiting growth arrest. We treated 5 human NB cell lines with RA, and observed a 2-5 fold induction of retinoic acid receptor alpha (RAR alpha) mRNA expression in 4 of the 5 cell lines, as an early cellular response. Induction of RAR alpha expression was specific for RA among several differentiating agents tested. RAR alpha mRNA expression in 13 primary neuroblastoma tumor samples was 3 fold higher in localised compared with advanced tumors (p < 0.05). RAR alpha expression may be necessary for the effects of RA on NB cells in vitro and reduced expression of this gene in vivo may contribute to the process of NB tumorigenesis.
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PMID:Regulation of retinoic acid receptor alpha expression in human neuroblastoma cell lines and tumor tissue. 801 44

Western blot analysis, using subtype-specific anti-G protein antibodies, revealed the presence of the following G protein subunits in human neuroblastoma SH-SY5Y cells: Gs alpha, Gi alpha 1, Gi alpha 2, Go alpha, Gz alpha, and G beta. Differentiation of the cells by all-trans-retinoic acid (RA) treatment (10 mumol/L; 6 days) caused substantial alterations in the abundance of distinct G protein subunits. Concomitant with an enhanced expression of mu-opioid binding sites, the levels of the inhibitory G proteins Gi alpha 1 and Gi alpha 2 were found to be significantly increased. This coordinate up-regulation is accompanied by functional changes in mu-opioid receptor-stimulated low-Km GTPase, mu-receptor-mediated adenylate cyclase inhibition, and receptor-independent guanosine 5'-(beta gamma-imido)triphosphate [Gpp(NH)p; 10 nmol/L]-mediated attenuation of adenylate cyclase activity. In contrast, increased levels of inhibitory G proteins had no effect on muscarinic cholinergic receptor-mediated adenylate cyclase inhibition. With respect to stimulatory receptor systems, a reciprocal regulation was observed for prostaglandin E1 (PGE1) receptors and Gs alpha, the G protein subunit activating adenylate cyclase. RA treatment of SH-SY5Y cells increases both the number of PGE1 binding sites and PGE1-stimulated adenylate cyclase activity, but significantly reduced amounts of Gs alpha were found. This down-regulation is paralleled by a decrease in the stimulatory activity of Gs alpha as assessed in S49 cyc- reconstitution assays.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Retinoic acid-induced differentiation of human neuroblastoma SH-SY5Y cells is associated with changes in the abundance of G proteins. 813 63

Western-blot analysis of human neuroblastoma SH-SY5Y cells (mu- and delta-receptors) revealed the presence of the following G-protein subunits: Gi alpha 1, Gi alpha 2, Gs alpha, G(o) alpha, Gz alpha, and G beta, a pattern resembling that observed in central nervous tissue. Chronic treatment of differentiated [all-trans-retinoic acid (10 microM; 6 days)] SH-SY5Y cells with D(-)-morphine (10 microM; 3 days) significantly increased the abundance of all G-protein subunits identified. Co-incubation of morphine-exposed cells together with naloxone (10 microM; 3 days) or the mu-selective opioid antagonist CTOP (10 microM; 3 days), but not with the delta-selective antagonist ICI-174,864 (10 microM; 3 days), completely abolished this effect, suggesting that the increase in G-protein abundance is specifically mediated by mu-receptors. Moreover, the biologically inactive enantiomer L(+)-morphine (10 microM; 3 days) failed to produce a similar effect. G-protein up-regulation developed in a time- and dose-dependent manner and is most likely due to enhanced protein synthesis de novo, since concomitant treatment of the cells with cycloheximide (100 micrograms/ml; 3 days) prevented this effect. Chronic treatment with the low-efficacy mu-selective opioid peptide morphiceptin (10 microM; 3 days), but not with the highly potent mu-agonist DAGO (0.1 microM; 3 days) produced a comparable increase in G-protein abundance. Coincident with quantitative effects on G-protein levels in morphine-tolerant/dependent SH-SY5Y cells, we found elevated levels of basal, forskolin (1 microM)- and prostaglandin-E1 (1 microM)-stimulated adenylate cyclase activities. Reconstitution experiments using S49 cyc- lymphoma-cell membranes suggest that this increase is most likely due to elevated levels of functionally intact Gs. Chronic treatment with both morphine and DAGO induces high degrees of tolerance in this cell line. However, the intrinsic activity of G1 was unchanged, as assessed in functional studies with low-nanomolar concentrations of guanosine 5'-[beta gamma- imido]triphosphate. Our data demonstrate that chronic treatment of SH-SY5Y cells with low-efficacy mu-opioids increases G-protein abundance, a phenomenon which might contribute to the biochemical mechanisms underlying opioid tolerance/dependence.
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PMID:Alterations in the expression of G-proteins and regulation of adenylate cyclase in human neuroblastoma SH-SY5Y cells chronically exposed to low-efficacy mu-opioids. 821 27

Newcastle disease virus (NDV), an avian pathogen, selectively replicates in and kills neuroblastoma (NB) cells, but not normal fibroblasts in vitro and in vivo in nude mice. NDV cytotoxicity towards NB cells is enhanced by N-myc oncogene amplification. To further define the antineoplastic effects of NDV, we examined NDV's interaction with NB cells following short-term exposure to the differentiating agent, all-trans retinoic acid (RA), and to neuraminidase. The human NB cell line IMR-32, after treatment with 50 mumol/L RA, became eight times more sensitive to NDV in a cytotoxicity assay. A time course study to determine the optimal incubation period of IMR-32 cells with RA indicated that a fourfold increase in sensitivity towards NDV killing occurred after only 8 hours of RA incubation prior to addition of virus. Maximal sensitivity was achieved at 24 hours of RA incubation and remained constant for longer incubation periods (up to 72 hours). The sensitization of IMR-32 NB cells to NDV was constant for RA doses between 3 mumol/L and 50 mumol/L. Plaque formation, which indicates replication, virus spread and cytotoxicity by a single infectious virus particle, was also enhanced by RA. This effect does not appear to require N-myc amplification in the target NB cells since RA had similar effects upon the high N-myc (IMR-32) and the low N-myc expressing cells (SK-N-SH). Enhanced sialylation has been shown by others to mediate the growth inhibitory effects of RA on a variety of tumor lines. Removal of sialic acid from the IMR-32 NB cell surface using Clostridium neuraminidase (2.7 mg/mL) inhibited 75% of NDV plaque formation. These results demonstrate that NDV killing of two NB cell lines is enhanced using clinically achievable levels of RA and that sialylation of the NB cell surface is important for virus binding and cytotoxicity.
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PMID:Retinoic acid enhances killing of neuroblastoma cells by Newcastle disease virus. 826 78

Most neuroblastomas with N-myc amplification, a sign of extremely poor prognosis, are extensively invasive to surrounding tissues. Therefore, we investigated the relationship between N-myc amplification and invasiveness of neuroblastoma cells, using an in-vitro assay system. Five human neuroblastoma cell lines were used for this study. IMR-32, GOTO, and DZ, all of which had N-myc amplification, showed a highly invasive capacity. In contrast, SK-N-SH without N-myc amplification showed extremely low invasiveness. ST unexpectedly showed high invasiveness in spite of the lack of N-myc amplification. Treatment of GOTO with 10(-5) mol/L all-trans-retinoic acid (RA) for 72 hours markedly decreased both N-myc expression and invasiveness. Treatment of GOTO with 2 mmol/L dibutyryl cyclic AMP (dbcAMP) for 72 hours caused a slight decrease of N-myc expression and invasiveness. These results indicate that N-myc amplification and expression might be closely related to the invasiveness of human neuroblastoma cells.
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PMID:The effect of N-myc amplification and expression on invasiveness of neuroblastoma cells. 833 99

The IMP dehydrogenase inhibitor, tiazofurin (TR)-2-beta-D-ribofuranosylthiazole-4-carboxamide, which exhibited oncolytic activity in patients with chronic myelogenous leukaemia (CML) in blast crisis was found to inhibit the growth of human neuroblastoma SK-N-SH cells with an IC50 of 4.2 microM. TR treatment of cells perturbed nucleic acid and catecholamine pathways. As biochemical markers of TR action decreased cellular GTP pools, increased inosine and hypoxanthine concentrations and depleted dopamine content were found. Incubation of tumour specimens obtained from paediatric patients with grade-IV neuroblastoma with TR resulted in the formation of the active metabolite, thiazole-4-carboxamide adenine dinucleotide, in concentrations sufficient to inhibit tumour growth. Cytotoxic and biochemical effects of TR were enhanced by combining it with allopurinol (an inhibitor of xanthine dehydrogenase), and hypoxanthine (an alternate substrate for hypoxanthine-guanine phosphoribosyltransferase). Induction of transdifferentiation of SK-N-SH cells from a neuroblast to an epitheloid, substrate-adherent phenotype was more pronounced with TR than with all-trans-retinoic acid. Transdifferentiating treatment with TR resulted in a 2-fold-enhanced sensitivity towards adriamycin. However, differentiation with all-trans-retinoic acid rendered the cells more resistant to adriamycin. Our results suggest that TR might be a promising agent for the treatment of children suffering from neuroblastoma.
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PMID:Cytotoxicity, differentiating activity and metabolism of tiazofurin in human neuroblastoma cells. 834 56

A series of human neuroblastoma (NB) cell lines was analyzed for expression of peripherin, a class-III intermediate filament protein expressed at high levels in ganglia of the peripheral nervous system. By Western blotting, peripherin protein was detected in all human NB cell lines examined. The highest level of peripherin was found in the NUB-7 cell line, previously characterized as homogeneously neuroblastic. By immunofluorescence labeling, peripherin was shown to be organized in a perinuclear filamentous pattern and, exemplified by IMR32 cells, was also shown to be localized to spontaneously formed neurites. Peripherin was expressed in neuroblastic but not substrate-adherent cells, and was found at low levels in I-type cells. There was a pronounced redistribution of peripherin to neurites formed in response to dibutyryl cyclic adenosine monophosphate (dbcAMP) and all-trans-retinoic acid (RA). In NUB-7 cells, which do not extend neurites in response to nerve growth factor, there was no change in the level of peripherin protein following treatment with this agent. Both dbcAMP and RA induced a redistribution of peripherin to neurite extensions, but only treatment with RA increased the level of the protein as demonstrated with NUB-6A4 and NUB-6C4 subclones. Peripherin was also variably expressed in peripheral neuroepithelioma (NE) cell lines tested, but was organized into a more basket-like filamentous pattern in these cells. The heterogeneous expression and distribution of peripherin in NB and NE cell lines indicate that this protein is associated with maturation of the neuronal phenotype and hence serves as a differentiation marker for tumors derived from the neural crest.
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PMID:Expression and distribution of peripherin protein in human neuroblastoma cell lines. 838 95


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