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

Mouse neuroblastoma cells in culture can be induced to differentiate morphologically by serum deprivation or by dibutyryl cyclic AMP (db-cAMP), e.g. they appear flattened, adhere more firmly to the culture substratum and extend long neuritic processes, and thus represent a widely used model system for neuronal cells. This differentiation is accompanied by modulation of cell surface components, such as the induction of a high molecular weight (HMW) glycoprotein (200 kD). We have studied the role of glycoproteins in the process of neuronal differentiation, using a purified homologue of the antibiotic tunicamycin (Al-tunicamycin) and neuroblastoma N115 cells grown in culture. Al-tunicamycin markedly inhibited (up to 60-75%) the incorporation of radioactively labelled sugars into cellular proteins of differentiating neuroblastoma cells. Concomitantly, the cells altered their morphology, they became rounded and less adhesive and retracted their neurites. Changes in the appearance, glycosylation and electrophoretic mobility of several cellular and secreted glycoproteins were observed, when cells were incubated in the presence of Al-tunicamycin. The most striking effect of Al-tunicamycin on the composition of cellular glycoproteins was the marked reduction in appearance of the 200 kD glycoprotein. The findings suggest that glycoproteins and in particular the neuron-specific 200 kD glycoprotein, are related to morphological differentiation processes, mainly to cellular adhesion and neurite outgrowth.
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PMID:Role of glycoproteins in neuronal differentiation. Inhibition of neurite outgrowth and the major cell surface glycoprotein of murine neuroblastoma cells by a purified tunicamycin homologue. 664 5

A human melanoma cell line, M14 , adapted to grow in serum free synthetic media was examined for its expression and secretion of several serologically defined melanoma associated antigens (MAA) previously described in this laboratory. Melanoma associated antigen expression and secretion was identical to that of M14 cells grown in parallel in serum supplemented medium. Spent synthetic media was found to be an enriched serum free source for the initial isolation of 100 kilodalton secreted glycoprotein MAA. M14 melanoma cells grown in synthetic media were also shown to be adaptable to the double agar clonogenic assay facilitating the examination of clonal heterogeneity in functional studies of MAA in melanoma tumor biology. Recent investigations from this laboratory have focused on characterizing human melanoma associated antigens (MAA) found either as secreted or cell surface associated glycoproteins in human melanoma cell lines. In these studies, monoclonal and polyclonal antiserums to melanoma cell components have been developed to specifically identify these MAAs immunochemically and provide a means to study the structural biochemistry of these determinants. At this time we have identified two antigens on which our research efforts are targeted: 1) a 100,000 dalton secreted glycoprotein (100K) common to melanoma, sarcoma and neuroblastoma tumor cell lines, and 2) a 250,000 dalton-high molecular weight component glycoprotein-proteoglycan complex which is thus far restricted to melanoma cells. The ultimate goal of our efforts is two-fold. Initially, we hope to develop schemes to isolate these melanoma associated antigens in sufficient quantities to obtain detailed structural information on these molecules, and secondly, we wish to implicate these glycoproteins in functional aspects of the biology of metastatic human melanoma in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Antigenic expression of human melanoma cells in serum-free medium. 673 Nov 48

The monoclonal antibody UJ 127-11 was raised following immunization of mice with human foetal brain and subsequent somatic cell hybridization of spleen cells with the mouse myeloma cell line P3-X63-Ag8-653. Studies on normal foetal and adult tissues show that, by indirect immunofluorescence, the antigen recognized by UJ 127:11 is restricted in its expression to cells of neural rather than glial origin. Neural tumours such as neuroblastoma, medulloblastoma and ganglioglioma (neural component) bind the monoclonal antibody whereas malignancies originating from glial cells do not bind UJ 127:11. Biochemically the monoclonal antibody has been shown to bind to a glycoprotein of 220,000-240,000 mol. wt. under reducing and non-reducing conditions. Despite similarities in the molecular weight between human fibronectin and the antigen recognized by UJ 127:11, they have different serological and biochemical characteristics, suggesting that the monoclonal antibody is not binding to either cell or plasma fibronectin.
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PMID:Monoclonal antibody UJ 127:11 detects a 220,000-240,000 kdal. glycoprotein present on a sub-set of neuroectodermally derived cells. 682 47

Interactions between neural cell surfaces seem to be of prime importance during neuroontogenesis, and responsible for the guidance of migrating neuroblasts and growing axons and for the formation of synapses. Little is known about the underlying molecular mechanisms, but most hypotheses imply the existence of cell-surface molecules that mediate the formation of transient or permanent bonds between neural cells. Recently, a membrane glycoprotein called neural cell adhesion molecule (N-CAM) has been characterized in chick and rodent nervous tissue that appears to act as a ligand in adhesion among neural cell bodies or neurites. We have identified a mouse neural surface glycoprotein, named BSP-2 (ref. 7), which by criteriaof electrophoretic migration, developmental changes, amino acid and sugar composition seems to be closely related or identical to N-CAM. Both BSP-2 (refs 8, 9) and N-CAM undergo conversion from an embryonic to an adult form during brain development and it has been suggested that this transition changes the adhesive properties or the binding specificity of the molecule. Using a neuroblastoma line to study functional differences between embryonic and adult BSP-2/N-CAM molecules, we show here that liposomes bearing adult BSP-2 but not those bearing the embryonic form adhere to neuroblastoma cells, demonstrating that the two forms do indeed possess different binding properties.
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PMID:Adult and embryonic mouse neural cell adhesion molecules have different binding properties. 687 55

Dopamine-beta-hydroxylase (D beta H), a glycoprotein enzyme which converts dopamine into noradrenaline, was purified from C1300 mouse neuroblastoma and used to raise antibodies in rabbits. Using an indirect immunofluorescence technique the cellular localization of D beta H in C1300 mouse neuroblastoma was compared with that of the superior cervical ganglion. C1300 neuroblastoma D beta H was found to be predominantly localized in the plasma membrane, in contrast to its intracellular localization in the superior cervical ganglion of A/J mice. At least part of the enzyme was found to be associated with the external side of the plasma membrane.
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PMID:Immunohistochemical evidence for a plasma membrane localization of dopamine-beta-hydroxylase in the mouse neuroblastoma. 699 45

A simple method is described that permitted rapid isolation of plasma membranes from mouse N-18 neuroblastoma cells. The purified plasma membranes gave a 10-fold increase in the specific activity of incorporated [3H]fucose over that of the cell homogenate. The specific activities of two other membrane markers, 5'-nucleotidase and alkaline phosphatase, increased 11-fold and 15-fold, respectively. Metabolic labeling with [3H]fucose identified a major fucosyl glycoprotein with apparent molecular weight of 92 000. Three surface labeling methods together with SDS-polyacrylamide gel electrophoresis and fluorography were used to characterize and compare the surface glycoproteins of undifferentiated and differentiated N-18 cells. The galactose oxidase/NaB3H4 method labeled two major galactoproteins (Mr = 52 000, 42 000) in both undifferentiated and differentiated cells. The neuraminidase/galactose oxidase/NaB3H4 method revealed many sialylgalactoproteins. Among them, the 220-kdalton, 150-kdalton and 130-kdalton bands were at least 100% more prominently labeled in the differentiated cells whereas the 76-kdalton and 72-kdalton bands were less prominently labeled in the differentiated cells when compared to their undifferentiated counterparts. The prominently iodinated protein bands in the undifferentiated cells had apparent molecular weights of 130 000, 92 000, 76 000 and 72 000 as compared to 150-, 130-, 92- and 76-kdalton bands in the differentiated cells. The labeling data obtained will enable us to further study the changes of these identified surface glycoproteins, both quantitatively and topologically, during the differentiation of neuroblastoma cells.
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PMID:Identification of exposed surface glycoproteins in undifferentiated and differentiated mouse N-18 neuroblastoma cells. 705 92

The deposition of the basement membrane glycoproteins, laminin, fibronectin, and type IV procollagen was studied by indirect immunofluorescence microscopy during the attachment and differentiation of murine C-1300 neuroblastoma cells. A typical cytoplasmic perinuclear staining for the basement membrane antigens was seen both in undifferentiated and differentiated cells. Freshly seeded suspended cells lacked surface fluorescence but in two hours after plating, distinct punctate laminin deposits became discernible on the ventral surface of the cells. Notably, in sparsely seeded undifferentiated cultures, the cell-associated extracellular laminin deposits could only be detected under the primary attaching cells, whereas daughter cells in clonal cell colonies lacked such fluorescence. In cultures induced to neurite formation with dibutyryl cyclic AMP, laminin deposition was also detected in association with the growing cytoplasmic extensions. No distinct differences were found between the secreted proteins of cultures of differentiated and nondifferentiated neuroblastoma cells, but the patterns of fucosylation of high-molecular weight proteins in the two cultures were markedly different. We conclude that cultured neuroblastoma cells both synthesize, secrete and deposit laminin. The distribution of laminin during neuroblastoma cell attachment and neurite extension suggests that this glycoprotein may be involved in cell-to-substratum interactions in C-1300 cell cultures.
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PMID:Deposition of basement membrane proteins in attachment and neurite formation of cultured murine C-1300 neuroblastoma cells. 706 77

We have previously identified a cell surface glycoprotein of the mouse nervous system named brain cell surface protein-2 (BSP-2). Here we report that this antigen is not a single, discrete entity, but a family of antigenically and structurally related molecules. Three components of 180, 140, and 120 K were characteristic for more mature nervous tissues. Adult cerebral cortex contained the 140-K and 120-K antigens, adult spinal cord only the 120-K, and dorsal root ganglia from young mice mainly the 180-K component. Very different forms of the antigen that migrated as a diffuse zone from 180-250-K in SDS-polyacrylamide gels were found in immature nervous tissues. A molecule different from the previous ones was found in a neuroblastoma line. Evidence is presented that the structural diversity of BSP-2 is due to differences in glycosylation. This result indicates that cell type- and developmental stage-specific glycoprotein patterns previously found in the nervous system may in part be due to different glycosylation of identical polypeptides. The finding that a neural cell surface protein may be glycosylated in different ways has important implications for the generation of cell surface specificity.
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PMID:Tissue- and developmental stage-specific forms of a neural cell surface antigen linked to differences in glycosylation of a common polypeptide. 718 49

Neurites were prepared by a novel method from differentiating mouse neuroblastoma cells. When electrically differentiated cells were labeled metabolically with L-[3H]fucose or D-[3H]glucosamine, both the neurites and the surface membranes showed the presence of a glycoprotein of apparent Mr = 200,000. In contrast, the level of this glycoprotein was reduced in the surface membranes from nondifferentiated cells and a radioactive glycoprotein of similar molecular weight was found in the growth medium. The method for the isolation of neurites is of potential usage in distinguishing specific proteins associated with growing neurites.
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PMID:A glycoprotein from neurites of differentiated neuroblastoma cells. 737 43

Nicotinamide deamidase (nicotinamide amidohydrolase, EC 3.5.1.19) has been demonstrated in the conditioned growth medium of the M1 clonal cell line of mouse C1300 neuroblastoma. The enzyme has been purified 1200-1500-fold by Sephadex G25, hydroxyapatite, DEAE-cellulose, Sephadex G200 and NAD-Sepharose column chromatographies. The purified protein was characterized by polyacrylamide gel electrophoresis under non-denaturing and denaturing conditions. The apparent molecular weight has been estimated to be 230,000, and the subunits had respective molecular weights of 65,000 and 50,000. Histidine was the only NH2-terminal amino acid found. The enzyme is a glycoprotein; mannose and N-acetyl-glucosamine have been identified. The effects of various ions on its activity have been investigated. The enzyme has a Km for nicotinamide in the order of 10(-6) M, a pH optimum of 7.2 and a pHi of 5.4. It is inhibited by heating and by sulfhydryl reagents. The existence of a nicotinamide deamidase with a high affinity for nicotinamide favors the operation of the Preiss-Handler pathway in M1 cells cultured in vitro. We found an induction of nicotinamide deamidase and a cellular increase of NAD with a higher nicotinamide supply and a repression of the released enzyme with supplying NAD in the nutrition medium of M1 cell cultures.
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PMID:Purification and characterization of a nicotinamide deamidase released into the growth medium of neuroblastoma in vitro. 737 17


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