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)

Cholera toxin (CT), covalently attached to horseradish peroxidase (HRP), is a specific cytochemical marker for GM1 ganglioside (GM1) and retains the ability of the native toxin to raise levels of cyclic AMP in avian erythrocytes. Using a cytochemical stain for HRP, we found that 9% of control cultured murine neuroblastoma cells bound cholera toxin-horseradish peroxidase conjugates (CT-HRP) on their surfaces after incubations for 1 h at 4 degrees C. Exogenous GM1, the natural receptor of CT, becomes associated in the culture medium with the plasma membranes of these cells so that 96% of cells are stained. Cells preincubated with GM1 at 4 degrees C were exposed to CT-HRP for 1 h at 4 degrees C. After washing, cells were incubated at 37 degrees C for 30 min-24 h. Endocytosis of CT-HRP occurred within 30 min and CT-HRP remained, throughout the 24-h period, in tubules, vesicles, and cisternae often found near the Golgi apparatus; this aggregate of peroxidase-positive elements probably corresponds to Golgi apparatus-endoplasmic reticulum-lysosomes (GERL) of neurons. In metaphase cells, CT-HRP was observed in aggregates of vesicles and tubules clustered near the centriole. Conjugates of HRP with subunit B, the GM1 binding component of CT, were internalized by cells pretreated with GM1 as was CT-HRP. The 9% of neuroblastoma cells binding CT-HRP in the absence of exogenous GM1 internalized the ligand in a manner indistinguishable from that of the treated cells. These findings indicate that, in neuroblastoma cells, a system of vesicles, tubules, and cisternae, analogous to GERL of neurons, is the primary recipient of adsorptive endocytosis of CT bound to endogenous or exogenously introduced GM1.
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PMID:Endocytosis of cholera toxin in GERL-like structures of murine neuroblastoma cells pretreated with GM1 ganglioside. Cholera toxin internalization into Neuroblastoma GERL. 45 74

Conjugates of horseradish peroxidase with the lectins ricin (d-galactose), wheat germ agglutinin (N-acetylglucosamine), phytohemagglutinin (N-acetylgalactosamine), and with cholera toxin (GM1 ganglioside) were used for a cytochemical detection of corresponding termin al carbohydrates, or glycolipids on cell surfaces of cultured neurons and neuroblastoma cells. Cells were labeled at 4 degrees C with the above ligands and their adsorptive endocytosis was studied after incubations at 37 degrees C in a medium free of ligand. Peroxidase was detected by the method of Graham and Karnovsky (J. Histochem. Cytochem. 14:291, 1966). Lectins and cholera toxin underwent endocytosis in cisternae and vesicles of GERL (Golgi-Endoplasmic Reticulum-Lysosome). We suggest that GERL is the primary ercipieint of adsorptively endocytosed plasma membrane "receptor"-ligand complexes which are thus degraded or possibly reutilized (recycling). Wheat germ agglutinin-horseradish peroxidase conjugates used in vivo for studies of retrograde axonal transport were significantly more sensitive than free horseradish peroxidase.
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PMID:The use of lectins and cholera toxin for the detection of surface carbohydrates of cultured neurons and neuroblastoma. 47 60

Because of the important biological functions of peroxidases, there is growing interest in the measurement of their concentrations in various secretions. At present, there is no standard method which allows for comparisons in reported activities. This report describes procedures which can be used to measure peroxidase enzyme concentrations by commonly employed assays. Regression equations have been determined which can be used to calculate concentrations of bovine lactoperoxidase (LPO), human salivary peroxidase (SPO), and human myeloperoxidase (MPO) from activities measured with the following donors: pyrogallol, guaiacol, 2,2'-azinobis(3-ethylbenzylthiazoline-6-sulfonic acid), and thiocyanate (SCN-). The peroxidation rates of these donors depend upon the concentrations of hydrogen peroxide (H2O2) used in the individual assays and thus, for accurate, reproducible results, these concentrations must be carefully controlled. The SCN- normally present in human saliva will reduce observed reaction rates by simple competition kinetics in the ABTS, guaiacol and pyrogallol assays and will increase the rates observed when Cl- is used as a donor in NBS assay for MPO. Therefore, SCN- must be removed from saliva samples prior to peroxidase activity determination by all assays except the thionitrobenzoic acid (NBS) assay. LPO cannot be used as a standard for either SPO or MPO because the specific activities of LPO, SPO, and MPO are significantly different.
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PMID:Quantitative, standardized assays for determining the concentrations of bovine lactoperoxidase, human salivary peroxidase, and human myeloperoxidase. 196 65

Binding of type C neurotoxin (C1 toxin) from Clostridium botulinum (strain Stockholm) to neuroblastoma cell lines was studied by using biotinylated anti-toxin antibody and avidin-biotinylated peroxidase complex. The neurotoxin bound with high efficiency to mouse neuroblastoma (NS-20Y and NIE-115) cells and to hybridomas of rat glioblastoma and mouse neuroblastoma (NG108-C15) cells. The toxin bound little to human neuroblastoma, rat astrocytoma, and nonneural cell lines. Binding of the neurotoxin to NG108-C15 cells was inhibited by gangliosides (GT1b and GM1) and by monoclonal antibodies (CA-12 and C-9), although inhibition was not complete. Sequential preincubation of C1 toxin with GT1b and CA-12 caused complete inhibition. A Scatchard plot of binding of 125I-labeled C1 toxin to NG108-C15 cells showed a hyperbolic curve. Monoclonal antibody CA-12 but not C-9 neutralized the lethal activity of the toxin toward mice. Only C-9 clearly inhibited toxin binding to GT1b. These results suggest that NG108-C15 cells have at least two kinds of receptors for C1 toxin. From the results of binding tests with neuraminidase-, pronase-, and trypsin-treated NG108-C15 cells, the chemical nature of the high-affinity site was presumed to be a glycoprotein containing sialic acid. GT1b may have an important role in low-affinity sites.
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PMID:Binding of Clostridium botulinum type C neurotoxin to different neuroblastoma cell lines. 253 34

The antigen recognized by a newly produced monoclonal antibody (bra55; IgG1) elicited by the non-T, non-B acute lymphoblastic leukemia cell line REH 6, was expressed on all examined hemopoietic neoplastic cell lines (including non-T, non-B, T, B and myeloid leukemia cell lines), but not on examined nonhemopoietic human tumor cell lines (such as carcinoma, sarcoma, melanoma and neuroblastoma cell lines), as demonstrated by indirect immunofluorescence and enzyme-linked immunoassay. Specific immunoprecipitation of 125I-lacto-peroxidase radioiodinated cell surface proteins and sodium metaperiodate/tritiated sodium borohydride 3H-radiolabeled cell surface sialoglycoproteins followed by electrophoretic analysis (SDS-PAGE) demonstrated that the immunoprecipitated antigen is a cell surface 200 kDa sialoglycoprotein (on the non-T, non-B ALL cell line REH 6), with variation in its electrophoretic mobility (in the Mr range of 170,000-210,000) on different examined cell lines. These properties are characteristic for the leukocyte common antigen (LCA, T200). Immunoperoxidase staining of several normal and malignant tissues, as well as some nonhemopoietic tumor tissues confirmed the type of antigen tissue distribution pattern characteristic for LCA.
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PMID:Human neoplastic cell line distribution, immunoprecipitation and immunohistopathological study of a gp200 cell surface glycoprotein (LCA) detected by a monoclonal antibody elicited with an ALL cell line. 296 36

Forty-one confirmed cases of childhood neuroblastoma diagnosed over a 13-year period were reviewed and reclassified. Most of the tumors were stained using a peroxidase antiperoxidase method for neuron specific enolase (NSE), protein gene product (PGP) 9.5, and S100 protein, all of which have previously been reported to be positive in some neuroblastomas. The relation to prognosis of the histology and immunohistochemistry was studied. There was a significant trend toward improved survival with increasing degree of differentiation, and with decreasing mitosiskaryorrhexis index (MKI) in the stroma-poor group. There was no significant correlation between immunohistochemical staining and survival, although the presence and amount of staining for all three markers tended to increase with tumor differentiation. This study concludes that histologic classification in neuroblastoma is helpful in assessing prognosis but that the clinical features are generally more reliable as indicators of prognosis. The immunohistochemistry of markers used did not contribute towards assessment of prognosis.
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PMID:Histologic and immunohistochemical investigation of neuroblastomas and correlation with prognosis. 296 64

'Suicide transport' is a term coined to describe the use of retrogradely axonally transported toxin to produce anatomically selective neural lesions. As a first step in developing neuron type-selective, systemically non-toxic suicide transport agents, a prototype hybrid toxin consisting of ricin A-chain (RTA) disulfide coupled to wheat germ agglutinin (WGA) was synthesized by first derivatizing WGA by reaction with N-succinimidyl-3-(2-pyridyldithio)-propionate (SPDP) in the presence of N-acetylglucosamine and then formation of WGA-SS-RTA by mixing the derivatized WGA with reduced RTA. The ability of this conjugate to inhibit protein synthesis was tested on two cell lines in vitro; the ID50 was 0.2 nM using the K562 hematopoietic stem cell line and 0.02 nM for the 2a neuroblastoma cell line. Suicide transport activity was assessed by microinjection of hybrid into the cervical vagus nerve of rats. Intact WGA-SS-RTA, but not hybrid that was pretreated with dithiothreitol to uncouple RTA from the WGA carrier, reliably killed vagal motor neurons. Both intact and reduced hybrid killed vagal sensory neurons. Indirect peroxidase immunohistochemistry demonstrated transport of RTA to vagal sensory neurons and WGA to both vagal sensory and motor neurons. These results are the first evidence that a hybrid toxin can be active as a suicide transport agent.
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PMID:Wheat germ agglutinin-ricin A-chain conjugate is neuronotoxic after vagal injection. 301 47

The immunoreactivity of VIP and PHI standards, immobilized on a nitrocellulose membrane, was first assayed with various detection procedures. For VIP, the double bridge peroxidase-antiperoxidase (PAP) method was the most sensitive procedure, giving a detection limit of 0.1-0.3 pmol per mm2 with the 4 rabbit anti-VIP antisera tested. By contrast, the detection limit of immobilized PHI was 100 times higher with the 4 rabbit anti-PHI/PHM antisera tested presumably because major antigenic sites were masked in the immobilized peptide. With this information at hand, the VIP and PHI immunoreactivity of human neuroblastoma NB-OK-1 cells was tested after extraction, SDS-PAGE, electrotransfer, and PAP immunodetection. Two faint immunoreactive bands corresponding to two pro-VIP forms with an Mr of, respectively, 19 kDa and 18 kDa, were detected in undifferentiated cells. These distinct bands increased progressively and markedly during differentiation in the presence of dibutyryl cyclic AMP. In addition, two intermediary VIP forms of lower Mr (11 kDa and 6 kDa) and 3 kDa VIP itself were also present after 2 days of differentiation. The 19 kDa and 18 kDa pro-VIP forms were detected with a sensitivity several times higher than that of VIP and their staining was specific for VIP epitopes. By contrast, when using 4 rabbit anti-PHI/PHM antisera, we observed essentially the strong unspecific staining of a 17 kDa polypeptide. VIP immunoreactivity was also visualized by immunocytochemistry in neuroblastoma cells cultured on glass coverslips and fixed in situ. Specific VIP staining using the PAP method was present in 10 percent of the cells in the undifferentiated state.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of two pro-VIP forms in a human neuroblastoma cell line. 301 4

We have isolated a heme protein from canine midbrains that possesses potent peroxidase activity. This enzyme catalyzes the oxidation of dopamine to neuromelanin in the presence of H2O2. We have further shown that the isolated peroxidase possesses potent cytotoxic activity in the presence of superoxide or H2O2 and Cl-. The enzyme possesses an endogenous NAD(P)H oxidase activity that can promote the cytotoxic activity by virtue of its production of superoxide. Other enzymes such as dihydroorotate dehydrogenase and galactose oxidase, which produce O2- and H2O2, respectively, are also effective in promoting the cytotoxic activity of the brainstem peroxidase. Although rat erythrocytes were routinely used as the target cell, other cell types, including rat hepatoma and mouse neuroblastoma cells, are also susceptible to the toxic action of the peroxidase. The cytotoxic action of the brainstem peroxidase is dramatically enhanced by kainic acid and is significantly enhanced by Mn2+, whereas dopamine was found to be a potent inhibitor of the cytotoxic activity. Based on these findings, we postulate a central role for the brainstem peroxidase in dopamine metabolism as well as in the biochemical and anatomical changes associated with Parkinson's disease.
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PMID:Neuromelanogenic and cytotoxic properties of canine brainstem peroxidase. 302 61

A procedure is described for assay of GM1 and other gangliotetraose-type gangliosides at the picomole level. The gangliosides are absorbed onto polystyrene microwells and treated with neuraminidase and then with cholera toxin B subunits conjugated to horseradish peroxidase. Color is developed and quantified spectrophotometrically. Omission of neuraminidase gives a measure of GM1 alone. Linearity was obtained between 0.5 and 3 pmol. This procedure was applied to ganglioside mixtures isolated fron neuro-2A neuroblastoma and PC12 pheochromocytoma cells. For the latter, an additional step involving reaction with fucosidase increased the yield of GM1 due to the presence of fucosylated gangliosides. Application of the same reagents as a TLC overlay procedure to the gangliosides from neuro-2A cells revealed the presence of GD1a, GD1b, and GT1b in addition to GM1, thus confirming the presence of a family of gangliotetraose gangliosides.
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PMID:Quantification of gangliotetraose gangliosides with cholera toxin. 318 15


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