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 monoclonal antibodies SMI-31 and SMI-34 react with phosphate-dependent epitopes of the high molecular mass (200 kDa) neurofilament protein (Hphos). Determination of whether or not these monoclonals react with different epitopes would assist in interpretation of post mortem immunocytochemical analyses in neurodegenerative disorders and in normal aging. We therefore examined the relative immunoreactivity of these antibodies against Triton-insoluble (cytoskeleton-associated) and Triton-soluble Hphos variants in NB2a/d1 neuroblastoma and post-natal mouse brain in immunoblot analysis. Densitometric analysis yielded a 'reactivity ratio' (soluble Hphos/insoluble Hphos) for each antibody. This ratio was approximately 44% and 87% less for SMI-34 than for SMI-31 in neuroblastoma and brain, respectively. These findings confirm that the SMI-34 epitope is distinct from that recognized by SMI-31, and, in these systems, is preferentially associated with the cytoskeleton.
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PMID:Evidence that the monoclonal antibodies SMI-31 and SMI-34 recognize different phosphorylation-dependent epitopes of the murine high molecular mass neurofilament subunit. 768 97

Gangliosides of the plasma membrane are important modulators of cellular functions. Previous work from our laboratory had suggested that a plasma membrane sialidase was involved in growth control and differentiation in cultured human neuroblastoma cells (SK-N-MC), but its substrates had remained obscure. We now performed sialidase specificity studies in subcellular fractions and found ganglioside GM3 desialylating activity in presence of Triton X-100 to be associated with the plasma membrane, but absent in lysosomes. This Triton-activated plasma membrane enzyme desialylated also gangliosides GD1a, GD1b, and GT1b, thereby forming GM1; cleavage of GM1 and GM2, however, was not observed. Sialidase activity towards the glycoprotein fetuin with modified C-7 sialic acids and towards 4-methylumbelliferyl neuraminate was solely found in lysosomal, but not in plasma membrane fractions. The role of the plasma membrane sialidase in gangliosides desialylation of living cells was examined by following the fate of [3H]galactose-labelled individual gangliosides in pulse-chase experiments in absence and presence of the extracellular sialidase inhibitor 2-deoxy-2,3-dehydro-N-acetylneuraminic acid. When the plasma membrane sialidase was inhibited, radioactivity of all gangliosides chased at the same rate. In the absence of inhibitor, GM3, GD1a, GD1b, GD2, GD3 and GT1b were degraded at a considerably faster rate in confluent cultures, whereas the GM1-pool seemed to be filled by the desialylation of higher gangliosides. The results thus suggest that the plasma membrane sialidase causes selective ganglioside desialylation, and that such surface glycolipid modification triggers growth control and differentiation in human neuroblastoma cells.
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PMID:Selective ganglioside desialylation in the plasma membrane of human neuroblastoma cells. 872 44

We examined the form(s) in which NF subunits undergo axonal transport. Pulse-chase radiolabeling analyses with 35S-methioinine revealed that newly synthesized Triton-soluble NF subunits accumulated within axonal neurites elaborated by NB2a/d1 neuroblastoma prior to the accumulation of Triton-insoluble subunits. Gel chromatographic, immunological, ultrastructural, and autoradiographic analyses of Triton-soluble axonal fractions demonstrated that radiolabeled, Triton-soluble subunits were associated with NFs. Triton-soluble, radiolabeled axonal NF subunits were also detected within retinal ganglion cell axons following intravitreal injection of 35S-methioinine. Microinjected biotinylated subunits were prominent within axonal neurites of NB2a/d1 cells and cultured dorsal root ganglion neurons substantially before they were retained following Triton-extraction. Prevention of biotinylated subunit, but not dextran tracer, translocation into neurites by nocodazole confirmed that microinjected subunits did not enter axons merely due to diffusion or injection-based pressure. Immuno-EM confirmed the association of biotin label with axonal NFs. These findings point towards multiple populations of NF subunits within axons and leave open the possibility that axonal NFs may be more dynamic than previously considered.
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PMID:Neurofilament subunits can undergo axonal transport without incorporation into Triton-insoluble structures. 960 71

Tau isoforms migrating at 46-68 and 97-115 kDa were prominent within heat-stable Triton-soluble material, and were present in lesser concentration with Triton-insoluble cytoskeletons, derived from undifferentiated SH-SY-5Y human neuroblastoma cells. Conversely, a 26-30 kDa tau isoform was enriched in the cytoskeleton and detected at relatively minor levels within cytosolic fractions. Pulse labeling with 35S-methionine indicated that this 26-30 kDa "small tau" did not represent a breakdown product of larger isoforms. Since the nucleus is retained within the Triton-insoluble cytoskeleton, additional cultures were fractionated onto sucrose to obtain purified nuclei. The vast majority of small tau was recovered within purified nuclei. Small tau was reactive with tau antibodies directed towards N-terminal, C-terminal and central epitopes, further confirming that this small isoform was not derived from proteolytic cleavage of larger tau isoforms. Small tau demonstrated alkaline phosphatase-sensitive reactivity with multiple phospho-dependent tau antibodies. Small tau was depleted within 3 days of retinoic acid-induced differentiation, suggesting that the putative function of this isoform may be obsolete following terminal differentiation of neurons.
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PMID:A 26-30 kDa developmentally-regulated tau isoform localized within nuclei of mitotic human neuroblastoma cells. 966 21

To investigate the intracellular compartmentalization of amyloid beta-protein (Abeta), human neuroblastoma SH-SY5Y cells were fractionated and the Abeta content in each fraction was quantitated by the well-characterized two-site enzyme-linked immunosorbent assay (ELISA). Subcellular fractionation of the cell revealed two distinct pools of Abeta within the cells: a Triton-soluble and a Triton-insoluble pools with the latter being larger than the former. Because Triton insolubility points to caveolae-like domains, we prepared detergent-insoluble, low-density membrane domains from SH-SY5Y cells using two different protocols. The low-density membrane fraction prepared by either protocol was found to contain a substantial proportion of intracellular Abeta40 and Abeta42. These results indicate that the distinct membrane domains are involved in the generation and/or trafficking of Abeta.
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PMID:The presence of amyloid beta-protein in the detergent-insoluble membrane compartment of human neuroblastoma cells. 979 84

1. Caveolins are integral proteins of glycolipid/cholesterol-rich plasmalemmal caveolae domains, where, they may function as a plasma membrane scaffold onto which many classes of signalling molecules, including receptors and heterotrimeric G proteins, can assemble. To ascertain whether caveolins influence G protein-mediated signal transduction, we stably expressed caveolin-1 and -3 isoforms in the neuroblastoma x glioma NG108-15 hybrid cell line, lacking endogenous caveolins. Subsequently, using whole-cell voltage clamp methods, we examined whether the modulation of N-type voltage-gated Ca2+ channels by G(o) protein-coupled, delta-type opioid receptors might be affected by recombinant caveolin expression. 2. In transfected NG108-15 cells, caveolins localized at the plasma membrane and, upon subcellular fractionation on sucrose density gradients, they co-localized in Triton-resistant, low buoyancy fractions, with endogenous G(o) protein alpha-subunits. 3. The voltage-dependent inhibition of omega-conotoxin GVIA-sensitive Ba2+ currents following either activation of delta-opioid receptors by the agonist [o-pen2,o-pen5]-enkephalin (DPDPE), or direct stimulation of G proteins with guanosine 5'-O-(thiotriphosphate) (GTPgammaS) was significantly attenuated in caveolin-expressing cells. The kinetics of Ca2+ channel inhibition were also modified by caveolins. 4. Overall, these results suggest that caveolins may negatively affect G protein-dependent regulation of voltage-gated N-type Ca2+ channels, presumably by causing a reduction of the available pool of activated G proteins.
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PMID:Attenuation of G protein-mediated inhibition of N-type calcium currents by expression of caveolins in mammalian NG108-15 cells. 1160 Jun 72

In this report we demonstrated that cellular prion protein is strictly associated with gangliosides in microdomains of neural and lymphocytic cells. We preliminarily investigated the protein distribution on the plasma membrane of human neuroblastoma cells, revealing the presence of large clusters. In order to evaluate its possible role in tyrosine signaling pathway triggered by GEM, we analyzed PrPc presence in microdomains and its association with gangliosides, using cholera toxin as a marker of GEM in neuroblastoma cells and anti-GM3 MoAb for identification of GEM in lymphoblastoid cells. In neuroblastoma cells scanning confocal microscopical analysis revealed a consistent colocalization between PrPc and GM1 despite an uneven distribution of both on the cell surface, indicating the existence of PrPc-enriched microdomains. In lymphoblastoid T cells PrPc molecules were mainly, but not exclusively, colocalized with GM3. In addition, PrPc was present in the Triton-insoluble fractions, corresponding to GEM of cell plasma membrane. Additional evidence for a specific PrPc-GM3 interaction in these cells was derived from the results of TLC analysis, showing that prion protein was associated with GM3 in PrPc immunoprecipitates. The physical association of PrPc with ganglioside GM3 within microdomains of lymphocytic cells strongly suggests a role for PrPc-GM3 complex as a structural component of the multimolecular signaling complex involved in T cell activation and other dynamic lymphocytic plasma membrane functions.
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PMID:Association of cellular prion protein with gangliosides in plasma membrane microdomains of neural and lymphocytic cells. 1237 9

We compared two commonly used calibration methods for measuring the concentration of intracellular free calcium ([Ca2+]i) by ratiometric fluorescence dye, fura-2 in mouse neuroblastoma-rat glioma hybrid cells (NG108-15). One calibration method, the Triton method, employs detergent Triton X-100, while the other, the Ionomycin method, uses a calcium-specific ionophore, Ionomycin. In the Triton method, we observed that at excitation 380 nm, the fura-2 fluorescence intensity of steady-state cells abnormally situated beyond the limiting intensity for calibration. By excitation scan, we demonstrated that this abnormality was caused by the change of fura-2 isosbestic points, which in turn was due to cell lysis after the addition of Triton X-100. This problem was resolved in the Ionomycin method by avoidance of cell lysis. Our results showed the correlation between inconsistent isosbestic points and cell lysis. As the basis for [Ca2+]i calibration, the proportionality between the fluorescence intensity and the concentration of dye species was impaired because of inconsistent isosbestic points. This inconsistency can be eliminated by a preliminary experiment of excitation scan to test the feasibility of different calibration methods.
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PMID:Abnormal spectra alteration observed in Triton calibration method for measuring [Ca2+]i with fluorescence indicator, fura-2. 1502 8

The transient receptor potential vanilloid type 1 (TRPV1) has been reported as one of the key components in the pain pathway. Activation of the receptor causes a Ca(2+) influx in sensory C-fibres with secondary effects leading to neurogenic inflammation in the surrounding tissue. We have earlier reported specific activation of TRPV1 by surfactant-containing hygiene products. We have continued this project by investigating activation of the TRPV1 by shampoo and soap ingredients in low concentrations measured as intracellular Ca(2+) influxes in stably TRPV1-expressing neuroblastoma SH-SY5Y cells. As a TRPV1 specific control, the TRPV1 antagonist capsazepine was used. The response was quantified as the product induced Ca(2+) influx during 2 min in relation to the maximum response induced by the TRPV1 agonist capsaicin. The results show that anionic alkyl linear surfactant ingredients such as sodium lauryl sulphate, sodium laureth sulphate, ammonium lauryl sulphate, sodium C12-15 pareth sulphate and N-lauroylsarcosine concentration-dependently induced Ca(2+) influx that could be addressed to TRPV1. The cationic surfactants benzalkonium chloride and cetylpyridinium chloride induced a Ca(2+) influx that was not TRPV1 mediated as well as the zwitterionic surfactant cocamidopropyl betaine, the non-linear anionic surfactant sodium deoxycholate and the non-ionic surfactant Triton-X. These results reveal a new mechanistic pathway for surfactant-induced nociception.
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PMID:Anionic linear aliphatic surfactants activate TRPV1: a possible endpoint for estimation of detergent induced eye nociception? 1954 Mar 28

The microtubule-perturbing drugs colchicine and taxol have been found to induce apoptosis in a CNS neuronal cell line. Apoptosis in drug-treated rat B103 neuroblastoma cells was evident in characteristic morphological changes, internucleosomal DNA fragmentation, and loss of nuclear content. Since colchicine and taxol have opposite actions on microtubule integrity, disruption of the active turnover of the microtubule network appears to be a crucial step for apoptosis to occur. It has been suggested that the basis for apoptosis by these drugs derives from their known block of the cell cycle at G2/M, but this does not appear the sole reason as both colchicine and taxol were able to evoke high levels of apoptosis in cells differentiated by Bt2cAMP or serum withdrawal. Further tests of cellular consequences of microtubule perturbation revealed a specific impact on signal transduction involving protein tyrosine phosphorylation. Immunoprecipitation with antibodies against tyrosine phosphorylated proteins showed a striking increase in the phosphorylation of a Triton-insoluble ~90 kDa protein, roughly concurrent with the onset of internucleosomal DNA fragmentation. Cycloheximide and genistein significantly reduced cell death and blocked appearance of the ~90 kDa tyrosine phosphorylated protein. Data suggest the hypothesis that signal transduction leading to apoptosis can be triggered by anomalous microtubule turnover and that the mechanism involves tyrosine phosphorylation of a ~90 kDa Triton-resistant protein.
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PMID:Increased Protein Tyrosine Phosphorylation in Apoptotic Neural Cell Death Due to Microtubule Perturbations. 2524 75


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