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)

P-glycoprotein, the product of the multidrug resistance (MDR1) gene, is an ATP-driven transmembrane pump that increases the resistance of cells by actively exporting toxic chemicals. In addition to transporting anticancer drugs, P-glycoprotein has been reported to extrude a variety of lipophilic drugs, such as calcium channel blockers, phenothiazines, cyclosporines etc. Interestingly, recent experiments suggest that steroid hormones may be physiologic substrates for P-glycoprotein. In addition, there exists a family of transporter genes with high structural homology to P-glycoprotein, the so-called ABC (ATP-binding casette) family. Although the physiological ligands for most of these transporters are unknown, there is increasing evidence that peptides may be transported by some of these proteins. Thus, the a-factor, a farnesylated pheromone with 13 amino acids, is exported from yeast cells by the product of the STE6 gene, a transporter protein with high homology to P-glycoprotein. Recently, we have cloned a novel member of the ABC-transporter gene family from neuroblastoma x glioma hybrid (NG-108-15) cells. This putative transporter gene ("NG-TRA") is expressed in the adrenal gland, kidney and in the brain. High amounts of NG-TRA mRNA are found in a variety of human brain tumors. Whether NG-TRA and/or other MDR-related transporters are involved in the transport of steroids, peptide hormones or growth factors remains to be established. If so, the cellular export of hormones by active pumps may represent a new mechanism of hormone secretion.
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PMID:New mechanisms of hormone secretion: MDR-like gene products as extrusion pumps for hormones? 135

The mechanisms that control herpes simplex virus type 1 latency and reactivation are still poorly understood. We developed an in vitro murine neuroblastoma cell HSV-infected, acyclovir suppressed model to study the influence of different cyclic nucleotide mediators on the latency and reactivation of HSV-1. A positive cDNA 'in situ' hybridisation for HSV genome was used to prove the establishment of a viral-host cell nuclear relationship. An ABC-immunoperoxidase reaction to cell surface HSV mature glycoproteins was also performed to determine the time of viral reactivation with formation of mature virions. Supernates of cultured cells were placed on Vero cells for confirmation of reactivation by classic cytopathic effect. Theophylline (50 micrograms/ml) and dibutyryl-cAMP (0.1, 0.5, 1 mg/ml) produced the most pronounced response, accelerating HSV reactivation time by 150%. Epinephrine (10, 20 micrograms/ml) had an intermediate effect on accelerating viral reactivation; and verapamil (20, 50 micrograms/ml), theophylline and epinephrine at lower doses had a smaller effect. Carbamylcholine (10 micrograms/ml) prolonged the time to viral reactivation by 100%, 36 hours compared to control time of 18 hours. Insulin (0.1, 0.5, 1 mg/ml) also prolonged HSV 'latency' by six hours. Exogenous dibutyryl-cGMP and carbamylcholine at lower concentrations did not have an effect on viral reactivation. These findings suggest that there is a relationship between changes of intracellular concentration of cyclic nucleotides and HSV latency and reactivation.
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PMID:The role of cyclic nucleotide mediators in latency and reactivation of HSV-1 infected neuroblastoma cells. 166 22

LFA-3, ICAM-1, HLA.ABC and HLA.DR expression was analyzed on 66 neuroblastoma specimens. HLA.ABC was expressed on 26 specimens, HLA.DR on 2, LFA-3 on 20 and ICAM-1 on 10. HLA.ABC and LFA-3 were positive on ganglioneuroblastoma or ganglioneuroma, but they were negative on neuroblastoma, independently of the clinical staging; HLA.ABC and LFA-3 were induced in vivo by chemotherapy in parallel with tumoral cell differentiation, in both the primary and the metastases. The expression of ICAM-1 was restricted to 5 of the 10 low-grade stage-1 or stage-2 specimens, 1 stage-3 specimen, and the primary tumors of 2 patients with stage-4 disease, analyzed hence at diagnosis and after chemotherapy (4 specimens); metastatic cells obtained in 1 of these patients were negative. HLA.ABC and LFA-3 expressed on both mycN-negative and -positive specimens, whereas ICAM-1 was restricted to MYCN-negative specimens. LFA-3 diffusely stained partially differentiated neuroblasts, Schwann cells and ganglion cells. The expression of HLA.ABC on differentiated neuroblasts varied from one sample to another and within the same tumor; Schwann cells were strongly positive, but ganglion cells were negative. In positive samples, ICAM-1 was expressed on differentiated neuroblasts and Schwann cells, but negative on ganglion cells; however, most of the differentiated tumors were ICAM-1-negative, suggesting ICAM-1 induction by unknown local signal. The 4 markers were negative on undifferentiated neuroblasts. The distribution of these 4 markers on clinical specimens was in agreement with their reactivity on fetal tissues, as well as with results obtained on neuroblastoma cell lines before and after in vitro treatment with IFN-gamma.
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PMID:Expression of leucocyte adhesion molecules on 66 clinical neuroblastoma specimens. 171 Jun 8

Confluent cultures of a human neuroblastoma cell line (CHP100) were incubated for 48 h with D-[1-3H]glucosamine and sodium [35S]sulphate. Radioactive glycosaminoglycans were analysed in the growth medium, rapid trypsin digest of the cell monolayer and a 1% (w/v) Triton/0.5 M NaOH extract of the final cell pellet. Sulphated glycosaminoglycans co-chromatographed when eluted by NaCl gradient from DEAE-cellulose. The medium contained mainly chondroitin sulphates, whereas the cell surface was enriched in heparan sulphate. Heparan sulphate was isolated as chondroitinase ABC-resistant material and treated with nitrous acid. Analysis of the scission products on Bio-Gel P-10 yielded fragments varying in size from single disaccharides to glycans consisting of nine disaccharide units. Cell-surface and medium heparan sulphate had respectively 52% and 54% N-sulphated glucosamine residues distributed in similar patterns along the polymer chain. The N:O-sulphate ratio of neuroblastoma heparan sulphate was 1.1:1. Analysis by high-voltage electrophoresis of di- and tetrasaccharide products produced by nitrous acid treatment showed that the distribution of 'O'-sulphate groups differed strikingly between heparan sulphates from the medium and cell-surface compartments. A di-O-sulphated tetrasaccharide was identified in both heparan sulphate species. The absence of detectable amounts of 35[S]sulphate associated with fragments larger than tetrasaccharide supports the close topographical association of N-sulphate and O-sulphate groups.
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PMID:Differences in the distribution of O-sulphate groups of cell-surface and secreted heparan sulphate produced by human neuroblastoma cells in culture. 622 67

Both polyvalent and hybridoma-produced antibodies to fibronectin (Fn) were used to 'map' the immunoaccessible subsets of cell surface fibronectin on virus-transformed murine fibroblast SVT2 and rat neuroblastoma B104 cells. As one approach to this end, attachment and spreading responses of cells were measured on tissue culture substrata coated with antibody or with plasma fibronectin to compare their adhesive responses. Both SVT2 and B104 cells adhere poorly to polyvalent anti-Fn-coated substrata over short time intervals, but within several hours changes occur which permit cells to attach and spread as well on anti-Fn as on Fn (post-adsorption of the anti-Fn with Fn also generates a maximal response). This adhesive response could be completely prevented by predigesting the cells with Flavobacterium heparanase, but not with chondroitinase ABC, indicating that the cell surface Fn responsible for antibody-mediated adhesion is associated with heparan sulfate proteoglycans on the cell surface. The compositions of the substratum-attached material (left bound after EGTA-mediated detachment of cells) from cells attaching to anti-Fn or Fn were analysed by SDS-PAGE and found to be identical within the same cell type for the two different substrata. Three hybridoma-produced antibodies, which recognize different determinants on Fn, generated different adhesive responses for SVT2 or B104 cells when adsorbed to the substratum. SVT2 cells adhered well to antibody no. 32-coated substrata but poorly to antibodies 92 or 136; on the other hand, B104 cells responded similarly to all three antibodies over short times of attachment but much better to no. 32 after a several hour incubation. These experiments indicate that (1) much of the cell surface fibronectin is complexed with heparan sulfate proteoglycan and is initially inaccessible to bind to polyvalent antibody on the substratum to promote adhesion; (2) the surface of neuroblastoma cells contains a fibronectin-like molecule which is important in their substratum adhesion; and (3) monoclonal antibodies are valuable tools in 'mapping' the orientation of cell surface molecules like fibronectin by measuring adhesive responses to antibody-coated substrata.
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PMID:Adhesive responses of fibroblast and neuroblastoma cells to substrata coated with polyvalent or monoclonal antibody to fibronectin. 686 9

The implementation of PULSE within the NBS will bring considerable advantages to the Service and to hospitals. A system of dual labelling has been developed to overcome intrinsic constraints identified with the ABC Codabar system. This should not, however, impact directly on hospitals which will be able to continue to utilize the ABC Codabar system. The dual labelling system incorporates the use of the ISBT Code 128 barcode system for transfusion centre use. This must be clearly differentiated from the implementation of ISBT code 128 within the UK. This latter development would bring considerable benefit to transfusion practice, increasing the overall safety of blood transfusion. It is, however, recognized that extensive discussion with appropriate stakeholders will be necessary before any implementation date can be determined for this initiative, particularly so given the significant logistical and financial implications inherent in such a change.
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PMID:ISBT Code 128 and code changes as part of the implementation of a national IT system for the English National Blood Service. 898 22

We developed a new vector for gene targeting of neuroblastoma (NB) cells, based on the utilization o a monoclonal antibody (chCE7) covalently linked to polylysine (PL). In the presence of chloroquine, chCE7-PL-DNA complexes transfected NB cells as efficiently as DOTAP, transfectam, TF-X50, or lipofectamine. This was demonstrated by transfection of the luciferase or beta-galactosidase reporter genes in three different NB cell lines. This transfection was specific, since it was inhibited in the presence of competing unconjugated chCE7 antibody (Ab), and was not observed in cell lines negative for the CE7 antigen. We tested the potential biological activity of a plasmid coding for gamma-interferon (gamma IFN) transfected with chCE7-PL. HLA ABC expression on NB cells was induced after transfection with pCMV-gamma IFN at a higher level than after incubation with 1000 IU/ml of purified gamma IFN. Moreover, these HLA ABC-positive NB cells were able to activate autologous cytotoxic T lymphocytes in vitro. Thus chCE7-PL is able to target a plasmid to NB cells and to allow the expression of the transfected gene in a biologically active form.
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PMID:In vitro targeting and specific transfection of human neuroblastoma cells by chCE7 antibody-mediated gene transfer. 908 6

Expression of P-glycoprotein was studied in formalin-fixed tissue sections from 75 materials with an immunoperoxidase (ABC) method using the monoclonal antibody MRK-16. Specimens examined were from three monkey fetuses, eight autopsy cases, and 64 neuroblastoma patients, 25 of whom were underwent mass screening for diagnosis. P-glycoprotein test results were positive in fetal lung alveolar tissue and in the adrenal medulla of three of seven adult autopsy cases. Expression of P-glycoprotein was demonstrated in 22 of 35 cases (63%) in a group of neuroblastoma patients younger than 12 months of age, as compared with 9 of 20 (31%) who were older than 12 months of age at diagnosis. P-glycoprotein positivity was higher in patients who were alive (25 of 40, 63%) than in those who had died (6 of 24, 25%). Previous studies on P-glycoprotein expression in neuroblastoma were carried out using specimens mainly from older children, and the results were not analyzed with reference to the findings in normal tissues. The present study has clearly shown that positive P-glycoprotein expression in neuroblastoma patients should be evaluated carefully in infant cases because it stains frequently in normal adrenal glands.
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PMID:Expression of multidrug resistance-related P-glycoprotein shows good prognosis in neuroblastoma. 909 7

Neurofilaments (NFs) are composed of a heteropolymer of three related subunits in mammalian neurons, where they are a major component of the cytoskeleton in large neurons and are thought to regulate axonal diameter. NFs in the lamprey, while ultrastructurally and functionally indistinguishable from mammalian NFs, are polymers of a single subunit protein, NF180. In this study, we use the simplicity of lamprey NFs and the accessibility of the lamprey central nervous system (CNS) to examine the effects of overproducing NFs in an identified giant neuron in vivo, and thus to elucidate the role of NFs in regulating neuronal size and axonal caliber in the vertebrate CNS. We show that overexpression of NF180 tagged with a variant of Green Fluorescent Protein (EYFP) in identified lamprey neurons (ABCs) and in human neuroblastoma (NB2a) cells results in the assembly of exogenous NF180 into ultrastructurally normal NFs that are tightly packed and unphosphorylated. These accumulate in the somata of NB2a cells and produce somatic swelling by 3 days post-transfection. NF180 overexpression in lamprey ABCs in vivo causes exogenous NFs to accumulate in ABC axons, somata, and dendrites, and induces a significant increase in axonal diameter without increasing axonal NF packing density. Overexpression of EYFP alone has none of these effects. We conclude that NF180 normally plays a critical role in determining axonal caliber in ABCs and may influence neuronal size in situations where NFs accumulate in the soma, such as after axonal injury.
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PMID:The single neurofilament subunit of the lamprey forms filaments and regulates axonal caliber and neuronal size in vivo. 1091 64

Prions replicate in the host cell by the self-propagating refolding of the normal cell surface protein, PrP(C), into a beta-sheet-rich conformer, PrP(Sc). Exposure of cells to prion-infected material and subsequent endocytosis can sometimes result in the establishment of an infected culture. However, the relevant cell surface receptors have remained unknown. We have previously shown that cellular heparan sulfates (HS) are involved in the ongoing formation of scrapie prion protein (PrP(Sc)) in chronically infected cells. Here we studied the initial steps in the internalization of prions and in the infection of cells. Purified prion "rods" are arguably the purest prion preparation available. The only proteinaceous component of rods is PrP(Sc). Mouse neuroblastoma N2a, hypothalamus GT1-1, and Chinese hamster ovary cells efficiently bound both hamster and mouse prion rods (at 4 degrees C) and internalized them (at 37 degrees C). Treating cells with bacterial heparinase III or chlorate (a general inhibitor of sulfation) strongly reduced both binding and uptake of rods, whereas chondroitinase ABC was inactive. These results suggested that the cell surface receptor of prion rods involves sulfated HS chains. Sulfated glycans inhibited both binding and uptake of rods, probably by competing with the binding of rods to cellular HS. Treatments that prevented endocytosis of rods also prevented the de novo infection of GT1-1 cells when applied during their initial exposure to prions. These results indicate that HS are an essential part of the cellular receptor used both for prion uptake and for cell infection. Cellular HS thus play a dual role in prion propagation, both as a cofactor for PrP(Sc) synthesis and as a receptor for productive prion uptake.
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PMID:Heparan sulfate is a cellular receptor for purified infectious prions. 1566 47


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