Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Murine erythropoiesis represents a favourable system in which to investigate the coordinate regulation of gene expression due to the availability of erythroid precursor cells at various stages of differentiation. In this report, we investigate the biosynthesis and cell specificity of two characteristic murine RBC membrane glycoproteins that resemble the human RBC glycophorins: a major component of apparent molecular mass 31 kD (glycophorin MA) and a minor 46 kD component (glycophorin MB). Both glycophorins bind to wheat germ lectin and share a common protein antigenic determinant recognised by a monoclonal antibody (GP 29.4), but they differ significantly in their carbohydrate components: whilst both glycophorins contain mainly O-linked sugars, glycophorin MA contains in addition at least one N-linked carbohydrate residue and terminal sialic acid residues. Pulse-chase in vivo labelling experiments combined with in vitro translations of glycophorin mRNAs show that the initial precursor to glycophorin MA is a 24.5 kD polypeptide which is subsequently processed and glycosylated to give the mature 31 kD molecule via a 21.5 kD polypeptide intermediate. Both glycophorins MA and MB are synthesized most actively in early to mid erythroblasts (e.g., Friend cells induced for 3 days with DMSO) but their synthesis is considerably reduced by the reticulocyte stage. However, of the other cell types tested (neuroblastoma, myeloma, fibroblasts, epithelial cells and T-lymphoma cells), none synthesizes glycophorin with the possible exception of a low level in thymus tissue. Thus murine glycophorins, in contrast to the RBC cytoskeletal proteins (spectrin, ankyrin, band 4.1) seem to be restricted to the erythroid cell lineage like human glycophorin.
 ...
PMID:The cell specificity and biosynthesis of mouse glycophorins studied with monoclonal antibodies. 385 53

Changes in the synthesis of concanavalin A binding proteins were analyzed at various times during nerve cell differentiation. Both mouse neuroblastoma cells as well as primary cells isolated from chicken dorsal root ganglia were used in these studies. Conditions were optimized for the biochemical differentiation of these cells, which were pulsed with radioactive methionine at several times during differentiation. Soluble extracts were prepared and optimum conditions for the isolation of those proteins which bind the lectin concanavalin A were determined. Incorporation of radioactivity into specific concanavalin A binding proteins was analyzed by two-dimensional gel electrophoresis and by computerized densitometry of the autoradiographs. Our results show that 10 concanavalin binding proteins are made only in differentiating neuroblastoma cells, and that twelve such proteins are made only in differentiating dorsal root ganglia cells. In addition, the synthesis of several other concanavalin A binding proteins increases dramatically during nerve cell differentiation. This class of proteins is now being further characterized by biochemical and immunological techniques.
 ...
PMID:Changes in synthesis of concanavalin A binding proteins during nerve cell differentiation. 408 85

The present study examines the endocytosis of conjugates of horseradish peroxidase (HRP) with ricin and wheat germ agglutinin (WGA) in rat adrenal pheochromocytoma cells (PC 12 line) cultured in the absence of nerve growth factor (NGF). In these cells acid phosphatase (ACPase) activity is not confined to a single cisterna and vesicles at the transaspect (mature face) of the Golgi apparatus which correspond to GERL of cultured neurons, neuroblastoma and other cell types. But ACPase is found in several cisternae of the Golgi apparatus as well as in lysosomes. On the other hand, thiamine pyrophosphatase activity, is found in a typical location within two or three cisternae of the Golgi apparatus near its transaspect. Following adsorptive endocytosis of HRP-labelled lectins (ricin-HRP or WGA-HRP) into PC12 cells, a reaction product is seen in dense bodies as well as in small vesicles and tubules throughout the cytoplasm, at the periphery of large vacuoles, in smooth and coated vesicles and tubules near the Golgi apparatus and in anastomosing tubules. The cisternae of the Golgi apparatus are not involved in the endocytosis of lectin-HRP. We conclude that in PC12 cells grown without NGF, unlike the case of cultured neurons and neuroblastoma cells, GERL is not segregated from the Golgi apparatus by either ACPase cytochemistry, or by the functional criterion of endocytosis of lectin-HRP conjugates.
 ...
PMID:In 'undifferentiated' PC12 cells, GERL is not segregated from the Golgi apparatus. 617 35

The effects of mitogenic lectins Phytohemagglutinin (PHA), and Concanavalin A (Con A) on the growth rate of cells derived from glial tumors (astrocytoma, ependymoma, glioblastoma, medulloblastoma, and C6 rat glioma), neural crest tumors (neuroblastoma and schwannoma), and meningiomas were studied. The cell lines were of human and animal origin. The specificity of lectin binding to mitogenic receptors was evaluated using complementary monosaccharides. In all glial- and some neural-crest tumor-derived cell lines, there was a lectin concentration-dependent and cell density-dependent, biphasic growth rate response with stimulation at low and inhibition at high lectin concentrations. This response did not depend on the type of glial tumor, species of origin, or passage level in vitro. Although, in meningioma-derived cell lines, lectins did not induce a growth rate response, they caused morphological changes ("whorling"). Lectin stimulation in glial tumor-derived cell lines resembles that occurring in peripheral blood lymphocytes. Lectin-induced mitogenesis may lay the groundwork for the establishment of a model of glial cell proliferation, and that permits the evaluation of cell surface effects, intracellular mechanisms, and epigenetic factors in studies of tumors, neural development, and neuroimmunology.
 ...
PMID:Mitogenic lectin receptors of nervous system tumors. Study of gliomas, neural crest tumors, and meningiomas in vitro using phytohemagglutinin and concanavalin A. 628 95

Electrophysiological studies with neuroblastoma cells have shown that toxin gamma from the venom of the scorpion Tityus serrulatus is a new toxin specific for the gating system of the Na+ channel. The procedure which solubilizes the tetrodotoxin receptor from rat brain also solubilizes the Tityus gamma toxin receptor. Binding experiments on the solubilized receptor with a radioiodinated derivative of Tityus gamma toxin have shown: (i) that the TiTx gamma-receptor complex is very stable with a dissociation constant of 8.6 X 10(-12) M and a very slow dissociation (T 1/2 = 15 h); (ii) that the toxin recognizes a class of sites with a 1:1 stoichiometry with those for tetrodotoxin (Bmax = 1.3 pmol/mg protein). The radioiodinated Tityus gamma-receptor complex has been substantially purified by ion-exchange chromatography, lectin affinity chromatography and sucrose gradient sedimentation. A ratio of one Tityus gamma toxin binding site per tetrodotoxin binding site was found throughout the purification. The purified material exhibited a sedimentation coefficient of 10.4S and had an apparent mol. wt. of 270 000 on SDS-gel electrophoresis. No other polypeptide chains were demonstrated to be associated with this large protein in the Tityus gamma receptor. The main conclusion is that the tetrodotoxin binding site associated with the selectivity filter of the Na+ channel and the Tityus gamma toxin binding site associated with the gating component are probably carried by the same polypeptide chain.
 ...
PMID:Electrophysiological characterization, solubilization and purification of the Tityus gamma toxin receptor associated with the gating component of the Na+ channel from rat brain. 631 20

T cells from the peripheral blood of a T-cell chronic lymphocytic leukemia (T-CLL) patient, cultured in the presence of interleukin-2 (IL-2), were found to express the p19 structural core protein of the human T-cell leukemia/lymphoma virus (HTLV) and to release type C virus particles. Comparison of the T-CLL cell line with the original leukemic T cells revealed that both the fresh and the proliferating T-CLL cells were pleomorphic cells that showed a convoluted nucleus and formed rosettes with sheep erythrocytes (E-rosettes). They were reactive with the monoclonal antibodies OKT1, OKT4 and OKT11, but not with OKT3, OKT6 or OKT8, indicating that they were mature T cells but that they differed from normal T cells in their lack of reactivity with OKT3. In addition they did not bind peanut agglutinin or OKM-1, and were negative for Epstein-Barr nuclear antigen, surface immunoglobulin, non-specific esterase activity of Fc- or complement receptors. Part of the fresh T-CLL cells reacted with a monoclonal antibody recognizing HLA-DR antigens (p29, 34) (36%) and with anti-Tac (62%), a monoclonal antibody directed at the IL-2 receptor, indicating that the T-CLL cells were partially activated already in vivo. After culture in vitro all proliferating T-CLL cells expressed HLA-DR and Tac antigens. The fresh T-CLL cells were found to be defective in cell-mediated lympholysis (CML) generated in mixed lymphocyte culture (MLC), antibody-dependent cellular cytotoxicity (ADCC) and lectin-dependent cellular cytotoxicity (LDCC). In addition they failed to exhibit natural killer (NK) cell activity against targets that are usually very susceptible to lysis, such as K562, but were able to kill two tumor-derived cell lines, the melanoma NKI-4 and the neuroblastoma CHP-100. The same pattern of selective killing was observed using the proliferating T-CLL cells as effectors, or cloned T-CLL cultures obtained from them by limiting dilution procedures. Therefore, it was concluded that the T-CLL cells represented a clonal expansion of neoplastic T cells that retained their phenotype and cytotoxic properties after culture in vitro.
 ...
PMID:Phenotypic and functional characterization of HTLV positive neoplastic T cells cultured with interleukin-2--I. Retention of morphology, phenotype and selective cytotoxic properties in long term culture. 632 59

Antibodies were raised against a cytoskeleton-associated, nonphosphorylated, 230,000-dalton bovine lens polypeptide (designated p230), and rendered monospecific by using a novel immunoaffinity technique. In immunofluorescence and electron microscopy of cultured fibroblasts, as well as of various other cells (endothelial, epithelial, lenticular, monocytes, neuroblastoma cells) and tissues (human kidney and liver), p230 was localized as a distinct subplasmalemmal layer in the peripheral cytoplasm of the cells. It constituted less than 0.3% of the total cellular protein in cultured fibroblasts and was not extractable with Triton X-100. In detergent-extracted cytoskeletal preparations of cultured fibroblasts, p230 remained as an elaborate peripheral network that showed a distribution distinctly different from that of the major cytoskeletal structures, stress fibers, cortical myosin, vinculin, and intermediate filaments (IF). The distribution was not dependent on the presence of intact stress fibers or microtubules, as shown by double-fluorescence microscopy of cells exposed to cytochalasin B or cultured in the presence of monensin and of cold-treated cells. Upon demecolcine-induced reorganization of intermediate filaments, however, the localization of p230 was rapidly altered to a dense plaque underneath the perinuclear aggregate of intermediate filaments. On the other hand, p230 seemed to colocalize with the detergent-resistant cell surface lamina, visualized in fluorescence microscopy with fluorochrome-coupled wheat germ agglutinin-lectin. The results suggest that p230 is part of a cell surface- and cytoskeleton-associated subplasmalemmal structure that may play an important role in cell surface-cytoskeleton interaction in various cells both in vitro and in vivo.
 ...
PMID:Immunolocalization of a novel, cytoskeleton-associated polypeptide of Mr 230,000 daltons (p230). 633 21

Concanavalin A (Con A) acceptors have been demonstrated in large differentiated neurons in a previous paper. In order to elucidate the correlation between Con A binding in normal and neoplastic neurons and lectin binding dependence upon the differentiation grade, 26 tumours of the neuronal series were examined using formalin fixed and paraffin embedded biopsy specimen. The neoplasms included 3 gangliocytomas, 7 gangliogliomas, 1 central neuroblastoma, 11 medulloblastomas, 2 retinoblastomas, and 2 sympathicoblastomas. Well differentiated neurons in gangliocytomas and gangliogliomas expressed a high intracytoplasmic Con A acceptor density comparable to the feature in large non-neoplastic neurons. Less differentiated neurons and neuroblasts showed a weak perinuclear fine granular binding or an absolute lack of binding molecules, respectively. Our results suggest that in a variety of tumours, Concanavalin A receptor density in neurons depends upon the degree of differentiation of the cell. Well differentiated cells have a higher density than poorly differentiated neoplastic neurons.
 ...
PMID:Concanavalin A binding and neuronal differentiation. A light microscopic study on neuronal tumours. 642 20

A method using proteins covalently coupled to glass surfaces has been applied to studies on the differentiation of neuroblasts. Neuroblastoma cells from clones N 18 and NIE 115 adhere to surfaces coated with fibronectin or laminin and extend rapidly growth cone-containing neurites. Some lectin-coated surfaces are also able to support neurite outgrowth, although the activities are lower than those of fibronectin and laminin. We discuss the biochemical requirements of the surface structures capable of inducing a differentiated neuronal morphology to neuroblastoma cells, and also consider the possible relationship of the results to physiological differentiation phenomena.
 ...
PMID:Neurite outgrowth of neuroblastoma cells induced by proteins covalently coupled to glass coverslips. 648 60

We report the development and characterization of SJ-9A4, a monoclonal antibody (MoAb) produced against common acute lymphoblastic leukemia (C-ALL) cell lines. SJ-9A4 reacted with C-ALL, B-cell chronic lymphocytic leukemia (B-CLL), platelets and C-ALL neuroblastoma (NB) and the K562 cell lines. It had no significant reactivity with erythrocytes, granulocytes, circulating T or B lymphocytes, monocytes, granulocytic cell lines or a Ewing's sarcoma cell line. SJ-9A4 was shown to recognize the same region as two other MoAb to the p24 antigen, BA-2 and DU-ALL-1, as demonstrated by their ability to inhibit the binding of labeled SJ-9A4 to NALM-1 and NB cells. Other MoAb: J5, PI 153/3 and monoclonal anti-HLA-DR antibodies gave no inhibition. A solid phase indirect radioimmunometric assay (IRA) was developed which enabled the detection of P24 from C-ALL cells, utilizing its ability to bind the Ricinus communis agglutinin (RCA1) or wheat germ agglutinin (WGA) and SJ-9A4 simultaneously. When BA-2 and DU-ALL-1 were used in place of SJ-9A4, similar IRA results were obtained. Using the RCA1/SJ-9A4-IRA, P24 from as few as 1.6 X 10(4) cells of a C-ALL cell line could be detected; however, similar extracts of NB cell lines were negative despite high levels of SJ-9A4 binding to intact cells. The presence of P24 in NB extracts was demonstrated by (1) preincubation of NB extracts with SJ-9A4 which blocked MoAb binding to P24 and (2) immunoadsorption of P24 from solubilized membranes of 35S-methionine (met) labeled NB cells. Treatment of NB cells with neuraminidase did not result in IRA binding when either RCA1 or WGA were used as the solid phase lectin indicating that the differences in lectin affinity are not due to over sialation of NB membrane glycoproteins. These findings demonstrate a difference in the glycosylation of P24 from C-ALL and NB cells.
 ...
PMID:A monoclonal antibody (SJ-9A4) to P24 present on common alls, neuroblastomas and platelets - I. Characterization and development of a unique radioimmunometric assay. 657 90


<< Previous 1 2 3 4 5 6 7 8 9 Next >>