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)

Nicotinic acetylcholine receptors (nAChR) composed of chick alpha7 subunits mutated to threonine at amino acid valine-251 in the putative channel-lining M2 domain were expressed heterologously in several neuron-like and non-neuronal mammalian cell lines. Expression of mutant alpha7-nAChR is toxic to neuron-like cells of the human neuroblastoma cell lines SH-SY5Y and IMR-32, but not to several other cell types. Growth in the presence of the alpha7-nAChR antagonist methyllycaconitine (MLA) protects against neurotoxicity, as does gradual downregulation of functional, mutant alpha7-nAChR in surviving transfected SH-SY5Y cells. Relative to wild-type alpha7-nAChR, functional alpha7-nAChR mutants show a higher affinity for agonists, slower rates of desensitization, and sensitivity to dihydro-beta-erythroidine (DHbetaE) as an agonist, but they retain sensitivity to MLA as a competitive antagonist. These findings demonstrate that expression of hyperfunctional, mutant forms of Ca2+-permeable alpha7-nAChR is toxic to neuron-like cells.
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PMID:Neurotoxicity of channel mutations in heterologously expressed alpha7-nicotinic acetylcholine receptors. 1140 78

1. The regulation of Maxi Cl(-) channels by 17beta-oestradiol and non-steroidal triphenylethylene antioestrogens represents a rapid, non-classical effect of these compounds. In the present study we have investigated the signalling pathways used for the regulation of Maxi Cl(-) channel activity by oestrogens and antioestrogens in C1300 neuroblastoma cells. 2. Whole-cell Maxi Cl(-) currents were readily and reversibly activated by tamoxifen, toremifene and the membrane-impermeant ethyl-bromide tamoxifen, only when applied to the extracellular medium. 3. Pre-treatment of C1300 cells with oestrogen or cAMP prevented the antioestrogen-induced activation of Maxi Cl(-) channels. The inhibitory effect of 17beta-oestradiol and cAMP was abolished by the kinase inhibitor staurosporine. 4. Current activation was unaffected by the removal of intracellular Ca(2+) and Mg(2+), but was completely abolished in the presence of okadaic acid. These results are consistent with the participation of an okadaic acid-sensitive serine/threonine protein phosphatase in the activation of Maxi Cl(-) channels. However, neither oestrogen or antioestrogen treatment modified the total activity of the two major serine/threonine phosphatases, PP1 and PP2A, in C1300 cells. 5. Although the role of these Maxi Cl(-) channels remains unknown, our findings suggest strongly that their modulation by oestrogens and antioestrogens is linked to intracellular signalling pathways.
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PMID:Okadaic acid-sensitive activation of Maxi Cl(-) channels by triphenylethylene antioestrogens in C1300 mouse neuroblastoma cells. 1157 58

Mice lacking expression of the p66 isoform of the ShcA adaptor protein (p66(ShcA)) are less susceptible to oxidative stress and have an extended life span. Specifically, phosphorylation of p66(ShcA) at serine 36 is critical for the cell death response elicited by oxidative damage. We sought to identify the kinase(s) responsible for this phosphorylation. Utilizing the SH-SY5Y human neuroblastoma cell model, it is demonstrated that p66(ShcA) is phosphorylated on serine/threonine residues in response to UV irradiation. Both c-Jun N-terminal kinases (JNKs) and p38 mitogen-activated protein kinases are activated by UV irradiation, and we show that both are capable of phosphorylating serine 36 of p66(ShcA) in vitro. However, treatment of cells with a multiple lineage kinase inhibitor, CEP-1347, that blocks UV-induced JNK activation, but not p38, phosphatidylinositol 3-kinase, or MEK1 inhibitors, prevented p66(ShcA) phosphorylation in SH-SY5Y cells. Consistent with this finding, transfected activated JNK1, but not the kinase-dead JNK1, leads to phosphorylation of serine 36 of p66(ShcA) in Chinese hamster ovary cells. In conclusion, JNKs are the kinases that phosphorylate serine 36 of p66(ShcA) in response to UV irradiation in SH-SY5Y cells, and blocking p66(ShcA) phosphorylation by intervening in the JNK pathway may prevent cellular damage due to light-induced oxidative stress.
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PMID:c-Jun N-terminal kinase specifically phosphorylates p66ShcA at serine 36 in response to ultraviolet irradiation. 1160 89

Calcineurin is a serine/threonine phosphatase involved in a wide range of cellular responses to calcium mobilizing signals. Previous evidence supports the notion of the existence of a redox regulation of this enzyme, which might be relevant for neurodegenerative processes, where an imbalance between generation and removal of reactive oxygen species could occur. In a recent work, we have observed that calcineurin activity is depressed in two models for familial amyotrophic lateral sclerosis (FALS) associated with mutations of the antioxidant enzyme Cu,Zn superoxide dismutase (SOD1), namely in neuroblastoma cells expressing either SOD1 mutant G93A or mutant H46R and in brain areas from G93A transgenic mice. In this work we report that while wild-type SOD1 has a protective effect, calcineurin is oxidatively inactivated by mutant SOD1s in vitro; this inactivation is mediated by reactive oxygen species and can be reverted by addition of reducing agents. Furthermore, we show that calcineurin is sensitive to oxidation only when it is in an 'open', calcium-activated conformation, and that G93A-SOD1 must have its redox-active copper site available to substrates in order to exert its pro-oxidant properties on calcineurin. These findings demonstrate that both wild-type and mutant SOD1s can interfere directly with calcineurin activity and further support the possibility of a relevant role for calcineurin-regulated biochemical pathways in the pathogenesis of FALS.
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PMID:Oxidative inactivation of calcineurin by Cu,Zn superoxide dismutase G93A, a mutant typical of familial amyotrophic lateral sclerosis. 1170 56

Dlk/ZIP kinase is a member of the Death Associated Protein (DAP) kinase family of pro-apoptotic serine/threonine kinases that have been implicated in regulation of apoptosis and tumour suppression. Expression of both Dlk/ZIP kinase and its interaction partner Par-4 is maintained in four medulloblastoma cell lines investigated, whereas three of seven neuroblastoma cell lines have lost expression of Par-4. Overexpression of a constitutively pro-apoptotic deletion mutant of Dlk/ZIP kinase induced significant apoptosis in D283 medulloblastoma cells. Cell death was characterized by apoptotic membrane blebbing, and a late stage during which the cells had ceased blebbing and were drastically shrunken or disrupted into apoptotic bodies. Over-expression of the anti-apoptotic Bcl-xL protein had no effect on Dlk/ZIP kinase-induced membrane blebbing, but potently inhibited Dlk/ZIP kinase-induced cytochrome c release and transition of cells to late stage apoptosis. Treatment with caspase inhibitors delayed, but did not prevent entry into late stage apoptosis. These results demonstrate that Dlk/ZIP kinase-triggered apoptosis involves the mitochondrial apoptosis pathway. However, cell death proceeded in the presence of caspase inhibitors, suggesting that Dlk/ZIP kinase is able to activate alternative cell death pathways. Alterations of signal transduction pathways leading to Dlk/ZIP kinase induced apoptosis or loss of expression of upstream activators could play important roles in tumour progression and metastasis of neural tumours.
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PMID:Dlk/ZIP kinase-induced apoptosis in human medulloblastoma cells: requirement of the mitochondrial apoptosis pathway. 1174 5

We have characterized a new member of the mammalian PAK family of serine/threonine kinases, PAK5, which is a novel target of the Rho GTPases Cdc42 and Rac. The kinase domain and GTPase-binding domain (GBD) of PAK5 are most closely related in sequence to those of mammalian PAK4. Outside of these domains, however, PAK5 is completely different in sequence from any known mammalian proteins. PAK5 does share considerable sequence homology with the Drosophila MBT protein (for "mushroom body tiny"), however, which is thought to play a role in development of cells in Drosophila brain. Interestingly, PAK5 is highly expressed in mammalian brain and is not expressed in most other tissues. We have found that PAK5, like Cdc42, promotes the induction of filopodia. In N1E-115 neuroblastoma cells, expression of PAK5 also triggered the induction of neurite-like processes, and a dominant-negative PAK5 mutant inhibited neurite outgrowth. Expression of activated PAK1 caused no noticeable changes in these cells. An activated mutant of PAK5 had an even more dramatic effect than wild-type PAK5, indicating that the morphologic changes induced by PAK5 are directly related to its kinase activity. Although PAK5 activates the JNK pathway, dominant-negative JNK did not inhibit neurite outgrowth. In contrast, the induction of neurites by PAK5 was abolished by expression of activated RhoA. Previous work has shown that Cdc42 and Rac promote neurite outgrowth by a pathway that is antagonistic to Rho. Our results suggest, therefore, that PAK5 operates downstream to Cdc42 and Rac and antagonizes Rho in the pathway, leading to neurite development.
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PMID:PAK5, a new brain-specific kinase, promotes neurite outgrowth in N1E-115 cells. 1175 52

We investigated the effect of vanadate, a tyrosine phosphatase inhibitor, on cell death induced by peroxynitrite in human neuroblastoma SH-SY5Y cells. Vanadate prevented cell death induced by 3-morpholinosydnonimine (SIN-1), a peroxynitrite donor; whereas SIN-1-induced cell death was not prevented by neither okadaic acid, an inhibitor of serine/threonine phosphatases 1 and 2A, nor cyclosporin A, an inhibitor of serine/threonine phosphatase 2B. Vanadate did not prevent cell death induced by N-ethyl-2-(1-ethyl-hydroxy-2-nitrosohydrazino)-ethanamine, a nitric oxide donor. Wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-kinase), did not block the protective effect of vanadate, suggesting that the protective effect of vanadate is independent on PI3-kinase. Vanadate increased tyrosine phosphorylation of several proteins including the focal adhesion protein p130 Crk-associated substrate (p130(cas)). By the treatment with SIN-1, the endogenous association of p130(cas) and Crk was disrupted, and the association was restored by vanadate treatment. These results suggest that disruption of tyrosine phosphorylation signaling may be critical for peroxynitrite-induced cell death, and that vanadate prevents cell death at least in part through the enhancement in tyrosine phosphorylation of the proteins including p130(cas).
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PMID:Vanadate protects human neuroblastoma SH-SY5Y cells against peroxynitrite-induced cell death. 1196 12

B -Catenin is closely associated with carcinoma invasion/metastasis and poor survival. Recent studies have demonstrated that abnormal expression of B -catenin, especially its nuclear accumulation, also plays an important role in wingless/Wnt signaling pathway. In this study, we evaluated immunohistochemically the nuclear localization of B -catenin in a total of 93 human-endocrine-related tumors including 1 medullary carcinoma (thyroid gland), 12 parathyroid tumors, 22 carcinoid tumors (digestive tract and liver), 7 islet cell tumors, 26 adrenocortical tumors, 13 neuroblastoma (adrenal gland), and 12 pheochromocytoma (adrenal gland), and also studied genetic alterations of the B -catenin gene. Nuclear accumulation of B -catenin was frequently detected in 8 of 22 (36%) carcinoid tumors and 2 of 7 (29%) islet cell tumors. No genetic alteration in exon 3 of the B -catenin gene encoding serine/threonine rich domain, which was phosphorylated by GSK-3 B, was detected in any groups of the endocrine tumors. However, nuclear accumulation of B -catenin in carcinoid tumors was significantly correlated with the proliferative marker Ki-67 (MIB-1) labeling index (p <0.001). Our findings suggest that nuclear transfer and accumulation of the B -catenin may contribute in the tumorigenesis of carcinoid tumor as an oncoprotein.
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PMID:Nuclear Accumulation of B-Catenin in Human Endocrine Tumors: Association with Ki-67 (MIB-1) Proliferative Activity. 1211 96

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are signal-transducing molecules that regulate the activities of a variety of proteins. In the present investigation, we have compared the effects of superoxide (O2-), nitric oxide (NO), and hydrogen peroxide (H2O2) on the activities of three highly homologous serine/threonine phosphatases, protein phosphatase type 1 (PP1), protein phosphatase type 2A (PP2A), and calcineurin (protein phosphatase type 2B). Although superoxide, generated from xanthine/xanthine oxidase or paraquat, and NO, generated from (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide or sodium nitroprusside, potently inhibited the phosphatase activity of calcineurin in neuroblastoma cell lysates, they had relatively little effect on the activities of PP1 or PP2A. In contrast, H2O2 inhibited the activities of all three phosphatases in lysates but was not a potent inhibitor for any of the enzymes. Calcineurin inactivated by O2-, NO, and H2O2 could be partially reactivated by the reducing agent ascorbate or by the thiol-specific reagent dithiothreitol (DTT). Maximal reactivation was achieved by the addition of both reagents, which suggests that ROS and RNS inhibit calcineurin by oxidizing both a catalytic metal(s) and a critical thiol(s). Reactivation of H2O2-treated PP1 also required the combination of both ascorbate and DTT, whereas PP2A required only DTT for reactivation. These results suggest that, despite their highly homologous structures, calcineurin is the only major Ser/Thr phosphatase that is a sensitive target for inhibition by superoxide and nitric oxide and that none of the phosphatases are sensitive to inhibition by hydrogen peroxide.
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PMID:Differential susceptibilities of serine/threonine phosphatases to oxidative and nitrosative stress. 1214 65

As reported previously [Acta Neurobiol. Exp. 57 (1997) 263], palmitoylcarnitine was observed to promote differentiation of neuroblastoma NB-2a cells with a concomitant inhibition of proliferation and of the phorbol ester stimulated activity of the protein kinase C (PKC). In the present study, palmitoylcarnitine was observed to inhibit phosphorylation of the PKC peptide substrate and to completely diminish binding of phorbol 12-myristate-13-acetate (PMA), although the effect was found to be uncompetitive. The exposure of NB-2a cells to palmitoylcarnitine in the presence of PMA resulted in a dramatic decrease in phosphorylation of the conventional and novel isozymes of PKC, mainly on serine. This effect was observed to be dose dependent. Inhibitors of serine/threonine phosphatases were not influencing the effect of palmitoylcarnitine what can point to an interaction between PKC and palmitoylcarnitine, affecting the process of autophosphorylation. These findings suggest that pamitoylcarnitine could be a natural modulator of PKC activity, thus regulating the process of cell differentiation.
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PMID:Interaction of palmitoylcarnitine with protein kinase C in neuroblastoma NB-2a cells. 1244 Nov 67


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