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)

PUFAs such as GLA (n-6) or DHA (n-3) were shown to exert antitumor activity on a human neuroblastoma cell line (NCG) and its VCR-resistant subline (NCG/VCR1, 8.6-fold resistant to VCR) in vitro. The NCG/VCR1 line had markedly decreased intracellular accumulation of [3H]-VCR and an accelerated drug efflux, compared to the NCG. The cytotoxic activity of PUFAs was correlated with the generation of MDA-like products in these cells. When VCR was added simultaneously with GLA or DHA to culture medium, the cytotoxic effect of VCR was about 2-fold enhanced, accompanied by about 1.5-2.0-fold increase of intracellular [3H]-VCR in both cell lines. Fatty acid analysis of membrane phospholipids of the NCG and the NCG/VCR1 cells treated with GLA or DHA showed an increased total PUFAs and SFAs, associated with markedly decreased total MUFAs and an inverted PUFAs/MUFAs ratio. Such phospholipid modification may have altered the membrane physical properties and enhanced the VCR cytotoxicity by increasing intracellular VCR accumulation; however, these PUFAs did not affect the drug efflux sufficiently enough to overcome completely the VCR resistance in the NCG/VCR1 cells. These results indicate that PUFAs partially alleviate the VCR-resistance in human neuroblastoma cells, not directly acting on VCR-resistance mechanism(s).
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PMID:Effects of polyunsaturated fatty acids on vincristine-resistance in human neuroblastoma cells. 188 52

1. Using [3H]DHA and unlabeled L-alprenolol, a substantial amount of over 64% specific binding of beta-adrenergic receptor has been identified on the neuroblastoma x glioma hybrid NG108-15 cell, which has been proven to display numerous functional characteristics of intact neurons. 2. Beta-adrenergic receptor binding on intact NG108-15 cells does not change significantly upon morphological differentiation, induced by 1 mM dibutyryl cyclic AMP (dBcAMP). 3. The [3H]DHA binding on intact NG108-15 cells is rapid, saturable, and reversible, having a t1/2 of 1.0 min for association and 3.5 min for dissociation. 4. The affinity constant (Kd) and maximum binding capacity (Bmax) for binding of [3H]DHA to beta-adrenergic receptors on NG108-15 cells have been estimated by Scatchard plot analysis to be 2.5 and 0.23 nM, respectively. Further analysis indicates a single class of receptors for [3HDHA binding on NG108-15 cells. 5. Studies on kinetic properties have revealed on-rate (K + 1) and off-rate (K - 1) constants of 0.7 X 10(-9) M min-1 and 0.19 min-1, respectively. Further, the IC50 value and inhibition constant (Ki) for unlabeled L-alprenolol to inhibit [3HDHA binding on NG108-15 cells have been estimated to be 10(-5) and 8.9 X 10(-6) M, respectively. 6. The rank-order potency of catecholamine agonists, (-)ISO greater than (+)ISO greater than EPI greater than NE, reveals the presence of type 2 receptor for the beta-adrenergic binding on both differentiated and undifferentiated NG108-15 cells. 7. The present study indicates that the clonal neuroblastoma x glioma hybrid NG108-15 cell line possesses substantial amounts of beta-adrenergic receptors with characteristics similar to those on neuronal cells.
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PMID:Identification and characterization of the beta-adrenergic receptor on neuroblastoma x glioma hybrid NG108-15 cells. 217 41

beta-Adrenergic receptors were demonstrated in membrane preparations from 6 human Ewing's sarcomas and compared to those from 46 other pediatric cancers with the use of the beta-adrenergic antagonist (-)-(3H)dihydroalprenolol [(-)[3H]DHA]. In contrast to the high numbers of receptor sites found in Ewing's sarcomas (55-640 fmol x mg-1 protein; dissociation constant Kd, 1-2 nM), other childhood cancers (neuroblastoma, rhabdomyosarcoma, brain tumors, lymphoma, osteosarcoma, hepatoblastoma, yolk sac, and Wilms' tumor) contained in general fewer beta-adrenergic receptor sites. Characteristics of (-)-[3H]DHA binding were therefore more fully characterized in the Ewing's tumors. Competition of (-)-[3H]DHA binding by classical catecholamine agonists, as well as by subtype selective agents metoprolol and zinterol, demonstrated the presence of a homogeneous population of beta 1-adrenergic sites in several Ewing's tumors. Adenylate cyclase activity in all Ewing's sarcomas was enhanced by GTP and NaF. However, in spite of high numbers of beta-adrenergic receptors, (-)-isoproterenol was not very effective in the activation of adenylate cyclase activity in several of the Ewing's tumors tested. Neither guanyl-5'-yl-imidophosphate nor GTP altered agonist potency for the receptor site in these catecholamine-insensitive tumors. Hill coefficients obtained from the competition experiments with (-)-isoproterenol (in the presence or absence of guanine nucleotide) were approximately 1.0. These uncoupled receptors were resistant to N-ethylmaleimide denaturation and were densensitized only 50% during culture in the presence of (-)-isoproterenol. Thus Ewing's sarcomas are relatively rich in beta-adrenergic sites, and several tumors appear to have a coupling lesion involving guanine nucleotide-dependent regulatory protein interaction with beta-adrenergic receptors and adenylate cyclase, similar in phenotype to that described in the (unc) variant of S49 mouse lymphoma.
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PMID:beta-Adrenergic receptors in pediatric tumors: uncoupled beta 1-adrenergic receptor in Ewing's sarcoma. 631 52

Pregnenolone, the precursor of all steroids, is synthesized by CNS structures. The synthesis requires an obligatory step involving cholesterol transport to mitochondrial cytochrome P450-cholesterol side chain cleavage (cytP450scc), although the underlying mechanism(s) are still mostly unknown. We used the human neuroblastoma SH-SY5Y cell line to investigate cytP450scc expression and activity and to establish a role of cytoskeleton in pregnenolone synthesis. Immunocytochemical and biochemical approaches revealed that undifferentiated as well as differentiated cells either by retinoic acid (RA) or phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), possess cytP450scc and rapidly synthesize pregnenolone in the presence of a NADPH-generating system. The newly neurosteroid formation by SH-SY5Y cells was increased by 22R-hydroxycholesterol and blocked by the cytP450scc inhibitor, aminoglutethimide. When trilostane was used to inhibit 3beta-hydroxysteroid dehydrogenase catalyzing pregnenolone conversion into progesterone, a higher pregnenolone accumulation occurred in TPA-differentiated cells than in RA-differentiated ones. Although SU 10603, a blocker of 17alpha-hydroxylase/c17,20-lyase enzyme involved in DHEA formation from pregnenolone, gave rise to an elevated neurosteroid content only in RA-differentiated cells. No difference in pregnenolone levels was found in undifferentiated cells treated with each inhibitor. Thus, differentiation seems to promote pregnenolone-metabolizing enzyme activities that may vary upon phenotypic changes induced by RA or TPA. Treatments of differentiated cells with the microtubule-depolymerizing drug colchicine and the actin microfilament-altering agent cytochalasin D decreased pregnenolone synthesis without affecting cell viability or cytP450scc amount. Addition of the cell-permeant cholesterol analogue 22R-hydroxycholesterol known to elude cholesterol transport systems induced pregnenolone synthesis, however, indicating that perturbations in cytoskeleton likely affect endogenous cholesterol transport. The relevance of this finding may rest on the observed involvement of cytoskeletal organization in such events as neuronal plasticity, cognitive function and also neurodegenerative disorders in which neurosteroids have been shown to have a part.
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PMID:Human neuroblastoma SH-SY5Y cell line: neurosteroid-producing cell line relying on cytoskeletal organization. 1082 Apr 37

Retinoic acid (RA) affects many cell types by either promoting their survival or inducing their differentiation. Dehydroepiandrosterone (DHEA), a precursor for both androgenic and estrogenic steroids and abundantly produced by brain, is known as an inhibitor of cell proliferation. Differentiation of a human neuroblastoma cell line (SK-N-BE) was evaluated measuring growth rate, motility, neurite extension and GAP-43 expression. We report that DHEA enhances the differentiating effect of RA on neuroblastoma cells via a signalling that is not RA receptor-mediated. Instead, we show a differential expression of matrix metalloproteinases: RA enhances the activity of MMP-2, whereas MMP-9 expression is up-regulated by DHEA. The concerted modulation of these proteinases may support the neurite outgrowth observed after co-treatment with the two drugs.
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PMID:Synergistic effect of retinoic acid and dehydroepiandrosterone on differentiation of human neuroblastoma cells. 1245 81

Japanese encephalitis virus (JEV), which causes neurological disorders, completes its life cycle and triggers apoptotic cell death in infected cells. Dehydroepiandrosterone (DHEA), an adrenal-derived steroid, has been implicated in protection against neurotoxicity and protection of animals from viral-induced encephalitis, resulting in an increased survival rate of the animals. Currently, the mechanisms underlying the beneficial effects of DHEA against the virus are largely unknown. In this study, DHEA suppression of JEV replication and virus-induced apoptosis in murine neuroblastoma (N18) cells was investigated. It was found that DHEA suppressed JEV-induced cytopathic effects, JEV-induced apoptotic cell death and JEV propagation in a concentration-dependent manner. Antiviral activity was more efficient in cultures treated with DHEA immediately after viral adsorption compared with that in cultures receiving delayed administration after adsorption or transient exposure before adsorption. JEV-induced cytotoxicity was accompanied by the inactivation of extracellular signal-regulated protein kinase (ERK). Inactivation of ERK by JEV infection was reversed by DHEA. When cells were treated with the ERK inhibitor U0126, DHEA lost its antiviral effect. Activation of ERK by anisomycin mimicked the action of DHEA in suppressing JEV-induced cytotoxicity. DHEA-related compounds, such as its sulfate ester (DHEAS) and pregnenolone, were unable to suppress JEV-induced cytotoxicity and ERK inactivation. The hormone-receptor antagonists ICI 182780 and flutamide failed to abrogate the antiviral effect of DHEA. These findings suggest that the antiviral effect of DHEA is not linked directly to the genomic steroid-receptor pathways and suggest that the signalling pathways of ERK play a role in the antiviral action of DHEA.
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PMID:Antiviral effect of dehydroepiandrosterone on Japanese encephalitis virus infection. 1609 10

In recent years, a number of studies have implicated the potent antioxidant property of astaxanthin in various experimental systems; however, these studies employed only the all-trans isomer. On the other hand, it has been reported that all-trans natural astaxanthin is readily isomerized to cis-trans, especially 9-cis and 13-cis isomers, under certain conditions by chemical analysis; however, the biological activities of the cis isomers of astaxanthin are little known. In the present study, we investigated the antioxidant activity of 9-cis and 13-cis astaxanthin compared to the all-trans isomer in vitro. In a stable radical DPPH scavenging activity test and in rat microsome and rabbit erythrocyte ghost membrane lipid peroxidation systems induced by AAPH and t-BuOOH, respectively, the results apparently showed that cis-astaxanthin, especially 9-cis astaxanthin, exhibited a higher antioxidant effect than the all-trans isomer. In addition, during polyunsaturated fatty acid (PUFA) oxidation, both DHA and linoleic acid hydroperoxides formation were markedly inhibited by astaxanthin isomers addition in the order 9-cis >13-cis >all-trans. Furthermore, 9-cis also exhibited the most effective inhibition of the generation of ROS induced by 6-hydroxydopamine (6-OHDA) in human neuroblastoma SH-SY5Y cells among the astaxanthin isomers, as well as on the degradation of collagen type II induced by DHA and linoleic acid hydroperoxides. The above-mentioned results suggest, for the first time, that cis isomer astaxanthin, especially 9-cis astaxanthin, has a much higher antioxidant potency than that of the all-trans isomer.
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PMID:Cis astaxanthin and especially 9-cis astaxanthin exhibits a higher antioxidant activity in vitro compared to the all-trans isomer. 1741 51

Neuronal apoptosis is involved in neurodegenerative diseases such as Alzheimer's disease and Parkinson.s disease. An efficient means of preventing it remains to be found. Some n-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA, 22 : 6n-3) and eicosapentaenoic acid (EPA, 20 : 5n-3) have been reported to be protective against the neuronal apoptosis and neuronal degeneration seen after spinal cord injury (SCI) [1]. However, it is unclear which kinds of PUFAs have the most potent ability to inhibit neuronal apoptosis and whether the simultaneous treatment of PUFAs inhibits the apoptosis. In the present study, we compared the abilities of various n-3- and n-6- PUFAs to inhibit the apoptosis induced after the administration of different apoptotic inducers, etoposide, okadaic acid, and AraC, in mouse neuroblastoma cells (Neuro2a). Preincubation with DHA (22 : 6n-3), eicosapentaenoic acid (EPA, 20 : 5n-3), alpha-linolenic acid (alpha-LNA, 18 : 3n-3), linoleic acid (LA, 18 : 2n-6), arachidonic acid (AA, 20 : 4n-3), and gamma-linolenic acid (gamma-LNA, 18 : 3n-6) significantly inhibited caspase-3 activity and LDH leakage but simultaneous treatment with the PUFAs had no effect on the apoptosis of Neuro2a cells. There were no significant differences of the anti-apoptotic eff ect among the PUFAs. These results suggest that PUFAs may not be effective for inhibiting neuronal cell death after acute and chronic neurodegenerative disorders. However, dietary supplementation with PUFAs may be beneficial as a potential means to delay the onset of the diseases and/or their rate of progression.
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PMID:Inhibitory effect of polyunsaturated fatty acids on apoptosis induced by etoposide, okadaic acid and AraC in Neuro2a cells. 1759 50

During the lipid peroxidation reaction, lipid hydroperoxides are formed as primary products. Several lines of evidence suggest that lipid hydroperoxides can trigger cell death in many cell types, including neurons. In a screening of lipid hydroperoxides which can induce toxicity in neuronal cells, we found docosahexaenoic acid hydroperoxides (DHA-OOH) induced much severe levels of reactive oxygen species generation and cell death in human neuroblastoma SH-SY5Y cells compared to the hydroperoxides of linoleic acid and arachidonic acid. Therefore, we focused on DHA-OOH, and demonstrated that DHA-OOH apparently induced an apoptosis in the neuronal cells through several apoptotic hallmarks including nuclei condensation, DNA fragmentation, poly (ADP-ribose) polymerase cleavage and increased activity of caspase-3. We also found the signaling changes in mitochondria-mediated apoptosis, such as cytochrome c release and increased expression of Bcl-2, as well as a dose-dependent attenuation of mitochondrial membrane potential in the DHA-OOH treated cells. These data indicated DHA hydroperoxide as a potential inducer of apoptosis in human neuroblastoma SH-SY5Y cells, which may be mediated by mitochondria dysfunction pathway.
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PMID:DHA Hydroperoxides as a Potential Inducer of Neuronal Cell Death: a Mitochondrial Dysfunction-Mediated Pathway. 1864 56

Docosahexaenoic acid (22: 6n-3; DHA) is a long chain polyunsaturated fatty acid that exists highly enriched in fish oil, and it is one of the low molecular weight food chemicals which can pass a blood brain barrier. A preliminary survey of several fatty acids for expression of growth-associated protein-43 (GAP-43), a marker of axonal growth, identified DHA as one of the most potent inducers. The human neuroblastoma SH-SY5Y cells exposed to DHA showed significant and dose-dependent increases in the percentage of cells with longer neurites. To elucidate signaling mechanisms involved in DHA-enhanced basal neuritogenesis, we examined the role of extracellular signal-regulated kinase (ERK)1/2 and intracellular reactive oxygen species (ROS) production using SH-SY5Y cells. From immunoblotting experiments, we observed that DHA induced the ROS production, protein tyrosine phosphatase inhibition, mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) phosphorylation, and sequentially ERK1/2 phosphorylation, the last of which was significantly reduced by MEK inhibitor U0126. Both antioxidants and MEK inhibitor affected DHA-induced GAP-43 expression, whereas the specific PI3K inhibitor LY294002 did not. We found that total protein tyrosine phosphatase activity was also downregulated by DHA treatment, which was counteracted by antioxidant pretreatment. These results suggest that the ROS-dependent ERK pathway, rather than PI3K, plays an important role during DHA-enhanced neurite outgrowth.
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PMID:Docosahexaenoic acid induces ERK1/2 activation and neuritogenesis via intracellular reactive oxygen species production in human neuroblastoma SH-SY5Y cells. 1899 96


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