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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the binding of tetanus toxin (TT) to surface receptors of neuroblastoma cells by flow cytometry following chemically induced differentiation. Cells were treated with mitomycin C, bromodeoxyuridine, prostaglandin E1 or cyclic adenosine monophosphate at different doses, alone or in combination for 4 days. Cells extended long neurites within 24 h in the presence of prostaglandin/cyclic AMP or mitomycin/bromodeoxyuridine treatment while single-drug treatment was less efficient in morphological differentiation of these cells. Cells exposed to the drug combinations stopped growing after 3 days while flow-cytometric analysis of DNA levels of each cell stained with propidium iodide indicated that at least 60% of these cells were arrested in phase G0/G1 of the cell cycle. Drug-treated cultures were stained for TT binding by immunofluorescence of cells in suspension and analyzed by flow cytometry. Chemically differentiated N2AB-1 cells were shown to bind significantly more TT than control cultures. Receptors for TT could be saturated by increasing doses of TT and differentiated cells bound twice as much toxin at saturation as did control cells. Immunofluorescence of TT binding to monolayers revealed staining in a stippled fashion along all neurites and cell bodies. These data support the concept that drugs which stimulate differentiation of neuroblastoma cells as determined by morphological and cell-cycle criteria also increase the presence of ganglioside receptors on the cell surface available for toxin binding.
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PMID:Tetanus toxin binding to neuroblastoma cells differentiated by antimitotic agents. 300 77

Tetanus toxin is known to bind neuronal tissue selectively. To study the interactions of this potent neurotoxin in an intact cell system, the binding of 125I-tetanus toxin was characterized in a neuroblastoma retina hybrid cell line, N18-RE-105. The binding of 125I-tetanus toxin to membranes prepared from N18-RE-105 cells showed many similarities to the interactions of 125I-toxin with rat synaptic membranes. The binding was decreased with increasing temperature, ionic strength, and pH. 125I-Toxin bound to membranes with high affinity: KD = 0.62 +/- 0.05 nM; Bmax = 196 +/- 45 pmol/mg protein. Quantitative thin-layer chromatography and acid-degradation analysis revealed that N18-RE-105 cells contained polysialogangliosides GD1a and GT1b in high concentrations. An assay was developed to quantitate surface-bound and internalized 125I-tetanus toxin by exploiting the observation that surface-bound 125I-toxin is susceptible to pronase digestion. When cells were incubated with 125I-tetanus toxin at 0 degree C, all of the bound 125I-toxin could be degraded with pronase. In contrast, when the incubations were performed at 37 degrees C, within 10 min about 50% of the total cell-associated 125I-toxin was pronase-resistant. Temperature pulse experiments demonstrated that 125I-tetanus toxin that was bound to cells at 0 degree C rapidly disappeared from the surface when the cells were warmed to 37 degrees C, as revealed by the appearance of pronase-resistant radioactivity. This internalization was sensitive to metabolic inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of the binding and internalization of tetanus toxin in a neuroblastoma hybrid cell line. 371 89

A neuroblastoma cell line was assessed for its capacity to bind tetanus toxin (TT) by using immunofluorescence and flow cytometry to analyze cells on a single cell basis. A clone of Neuro 2a, N2AB-1, was shown to bind variable amounts of TT per cell and this binding could be saturated by increasing doses of the toxin. Toxin binding was specific for neuronal cells, as the non-neuronal cell line, C6 glioma, bound negligible amounts of toxin. Variability of immunofluorescence staining was due in part to the increase in size of N2AB-1 cells as they progress through the cell cycle as measured by cell surface densities of toxin binding and DNA levels by propidium iodide (PI) staining. When N2AB-1 cells were treated with exogenous gangliosides for 24 h, cells were induced to sprout neurites and cell growth was inhibited. Analysis of DNA histograms indicated that ganglioside treatment caused more cells to appear in G0G1 of the cell cycle than that seen for untreated controls. Upon cytometric analysis of TT binding to ganglioside treated cells, it was apparent that treatment stimulated all cells to bind TT in larger amounts per cell than that seen with untreated N2AB-1 cells. These data suggest that TT binding and, therefore, toxin receptors are constant in density throughout the cell cycle of these neuroblastoma cells and that exogenous gangliosides can cause differentiation followed by increased toxin binding.
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PMID:Flow cytometric analysis of tetanus toxin binding to neuroblastoma cells. 390 30

Tetanus toxin (TT) was used as a diagnostic marker for human neuroblastoma (NB) cells. TT binding sites visualized by TT and FITC-conjugated anti-TT antibodies were present on NB cells from all 13 cases studied comprising Stages II, III, IV, IVS and histologic grades 1 through 3. NB cells from both bone marrow aspirates and tumor biopsies as well as cultured NB cells were TT-positive. Diagnosis of NB was further ascertained by electron microscopy, cell culture, and quantitative determinations of catecholamines in tumor material. Only electron microscopic diagnoses had an accuracy comparable to that of TT labeling. None of the non-NB tumors (Ewing's sarcoma, acute lymphatic and myeloic leukemia, acute monocyte leukemia, chronic myeloic leukemia, Hodgkin's disease, oat cell carcinoma of the lung, pheochromocytoma), except for the pheochromocytoma, were found to bind TT specifically. These results suggest that TT may be profitably employed as a diagnostic marker of human NB cells. The advantages of the methods are its high discriminative capacity against non-NB cells and rapid applicability.
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PMID:Tetanus toxin labeling as a novel rapid and highly specific tool in human neuroblastoma differential diagnosis. 400 7

The slow action potential of mouse neuroblastoma N1E-115 cells, which was elicited in Na-free medium and whose amplitude was directly dependent on extracellular Ca concentrations, was blocked by tetanus toxin (TNTX) without change in resting membrane potential and resistance. The average value of action potential overshoot (peak potential level of spikes) in the absence and presence of TNTX was -1 and -11 mV, respectively. The concentration of TNTX required for 50% inhibition of Ca-dependent spikes (IC50) was about 65 ng/ml. The amplitude of spikes was decreased within 10-20 min after adding TNTX. The inhibition of Ca-dependent spikes was mimicked by 10 mM CoCl2 and MnCl2, but not by the boiled or neutralized toxin. The results indicate that TNTX inhibited electrogenesis of Ca, but not Na, components of action potentials of the neuroblastoma cells.
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PMID:Tetanus toxin: a rapid and selective blockade of the calcium, but not sodium, component of action potentials in cultured neuroblastoma N1E-115 cells. 631 81

Monoclonal and polyclonal L1 antibodies react by indirect immunofluorescence with the cell surface of cultured tetanus toxin-positive neurons from post-natal cerebella of mice, but not with glial fibrillary acidic protein-positive astrocytes, O4 antigen-positive oligodendrocytes or fibronectin-positive fibroblasts or fibroblast-like cells. During cerebellar development L1 antigen is detectable on tetanus toxin-positive cells as early as embryonic day 13 after 3 days in culture. In sections of the early post-natal cerebellum, L1 antigen is found on pre-migratory neurons in the internal, but not in the external part of the external granular layer. In the adult cerebellum, L1 antigen is predominantly localized in the molecular layer and around Purkinje cells. Fibers in white matter and the granular layer are also L1 antigen-positive. Granule cell bodies and synaptic glomeruli are weakly antigen-positive. Several cell lines derived from neuroblastoma C1300 also express L1 antigen. The antigen is not detectable by enzyme-linked immunosorbent assay in tissue homogenates of liver, kidney, lung, heart, sperm or thymus. With polyclonal L1 antibodies, cross-reactive determinants are found in brains of rat, guinea pig, hamster, chicken, rabbit and man, but not in frog, while monoclonal antibody reacts detectably only with mouse brain. The molecular species recognized by both monoclonal and polyclonal antibodies display two prominent bands by SDS-PAGE under reducing and non-reducing conditions with apparent mol. wts. of 140 and 200 kd. L1 antigen isolated from cultured cerebellar cells consists mainly of a band in the 200-kd range and a faint one at 140 kd. L1 antigen from neuroblastoma N2A shows two bands with slightly higher apparent mol. wts. All molecular forms of L1 antigen can be labeled by [3H]fucose and [3H]glucosamine. Ca2+-independent re-aggregation of cerebellar cells from early post-natal C57BL/6J mice and of the continuous cell line N2A derived from the murine neuroblastoma C1300 is inhibited by Fab fragments of the polyclonal, but not of monoclonal antibody, both of which are known to react with the surface membrane of these cells.
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PMID:Immunocytological and biochemical characterization of a new neuronal cell surface component (L1 antigen) which is involved in cell adhesion. 636 20

We examined the effect of tetanus toxin on clonal neuroblastoma X glioma hybrid cells, NG108-15, by intracellular microelectrode studies of passive membrane electrical properties and action potentials generated under various conditions. Binding of tetanus toxin to the surface of the cells was demonstrated by indirect immunofluorescent staining but no morphological alteration was observed in tetanus toxin-treated cells under a phase contrast microscope. These is no significant difference between the tetanus toxin-treated and untreated cells in their passive electrical membrane properties, i.e. resting membrane potentials, input resistances, time constants and input capacities. Cells in 120 mM Na+, 2 mM Ca2+ salt solution showed Na spikes, and cells in high Ca2+ (30 mM), Na+-free salt solution showed Ca spikes in response to depolarizing current pulses. While the Na spike was not affected by tetanus toxin, the Ca spike was blocked by the toxin. The minimum dose of tetanus toxin for maximum suppression of the peak potential level of the Ca spike was 250 ng/ml. Addition of tetraethyl ammonium (TEA) to extracellular fluid enhanced the Ca spike in untreated cells. In toxin-treated cells, TEA did not alter the effect of tetanus toxin on the Ca spike. Blockade of the Ca spike by tetanus toxin could be detected even at low extracellular Ca2+ concentration (10 mM) by adding TEA to the extracellular fluid and adjusting the membrane potential to a steady hyperpolarized level (-80 mV) to ensure optimal and uniform electrical responses. The usefulness of NG108-15 hybrid cells for in vitro investigations on the mechanism of action of tetanus toxin was discussed.
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PMID:Action of tetanus toxin on cholinergic neuroblastoma X glioma hybrid cells: selective blockade of Ca spikes. 637 74

The effect of tetanus toxin on the Ca spike of the action potential evoked in neuroblastoma clone N1E-115 cells by constant current stimulation in Na+-free medium containing various concentrations of Ca2+(1.8-80 mM) was examined by intracellular recordings. Tetanus toxin (more than 140 ng/ml) blocked the Ca spikes. The resting membrane potentials and membrane input resistances of tetanus toxin-treated cells were similar to those of untreated cells. The blocking effect of tetanus toxin was evident in medium containing Ca2+ at concentrations of more than 30 mM. The difference between the peak levels of the action potentials of toxin-treated and untreated cells was statistically significant at Ca2+ concentrations of 7.2 mM and more.
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PMID:Tetanus toxin blocks Ca spikes in neuroblastoma clone N1E-115 cells. 662 23

Mature T cells are susceptible to activation-induced cell death in the periphery. Activation-induced cell death is thought to involve CD95/CD95 ligand interactions in vivo. Here we report that stimulated, CD45RO+ human T cell lines specific for myelin basic protein or tetanus toxoid from multiple sclerosis patients and healthy individuals resist apoptosis induced by soluble recombinant CD95 ligand in vitro. In contrast, the same CD95 ligand effectively kills Jurkat T lymphoma and human malignant glioma cells. The resistance of the T cell lines is not due to a lack of CD95 expression at the cell surface and is not overcome by coexposure to CD95 ligand and inhibitors of RNA or protein synthesis. The expression level of BCL-2 is lower in Jurkat than in Ag-specific T cells. After exposure to soluble CD95 ligand, Jurkat T cells, but not Ag-specific T cells, exhibit loss of BCL-2 and BCL-X expression whereas BAX expression is not affected. Surprisingly, Ag-specific T cells are rather sensitive to CD95 ligand expressed at the cell surface of N2A neuroblastoma cells. Accessory molecules expressed by the CD95 ligand-expressing effector cell are dispensable for apoptosis since the T cells are equally sensitive to agonistic APO-1 Ab. Further studies are required to determine whether resistance to soluble CD95 ligand-mediated apoptosis is a possible escape mechanism for T cells from peripheral deletion that may have relevance for autoimmune disorders.
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PMID:Human autoreactive and foreign antigen-specific T cells resist apoptosis induced by soluble recombinant CD95 ligand. 927 96

Analysis of the molecular factors that control cellular differentiation in mammalian embryos is difficult due to the small amount of material available from embryos and their inaccessibility during gestation. One way to circumvent these limitations is to use model systems that allow the study of differentiation in vitro. In this study we have characterized the response of a human neuroblastoma cell line, LA-N-5, to the differentiation-inducing agent, all-trans retinoic acid (RA) using 23 markers that are characteristic of neural crest cells and some of their derivatives. Following induction with RA, the neural crest-like LA-N-5 cells undergo differentiation into cholinergic neurons with increased expression of a variety of neural-specific markers including neurofilaments, growth associated protein-43, tetanus toxin binding sites, receptors for neurotrophic factors, neuropeptides, choline acetyl transferase, vesicular acetylcholine transporter, and acetylcholinesterase with a concomitant decrease in the expression of non-neuronal markers. These results provide the basis for the use of retinoic acid-induced differentiation of LA-N-5 cells as a model system to study molecular events associated with the differentiation of cholinergic neurons.
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PMID:Characterization of the cholinergic neuronal differentiation of the human neuroblastoma cell line LA-N-5 after treatment with retinoic acid. 929 34


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