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)

The microtubule-associated protein tau, and the cytoplasmic protein ubiquitin, are constituents of pathological neurofibrillary tangles found in Alzheimer's disease. In order to see if there is any physiological relationship between these proteins in a functioning human system, human neuroblastoma (LAN-5) cells were grown in vitro and differentiated to a neuronal phenotype. Cell extracts were analyzed by SDS-PAGE, immunoblot, and immunoprecipitation techniques. The colocalization of ubiquitin and tau immunoreactivity was noted in 12- and 35-kDa bands, predominantly located in a cell membrane fraction. The bands were also isolated by immunoprecipitation with the Alz-50 antibody and then identified with a ubiquitin antiserum. These findings show a relationship between tau and ubiquitin in a human neural cell line. This interaction suggests that tau may normally be degraded by an ubiquitin-dependent mechanism and alterations in it may contribute to the formation of neuro-fibrillary pathology.
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PMID:Tau-ubiquitin protein conjugates in a human cell line. 172 70

Biochemical events leading to the formation of mature membrane-associated sodium channel proteins are not completely understood. We have recently purified a protein from the cytoplasm of brain cells, which is able to become incorporated into liposomes and induce neurotoxin-dependent sodium permeability. Here we report data on a monoclonal antibody derived against this protein. This antibody crossreacts with cell membrane preparations. The antibody binding to viable neuroblastoma cells is inhibited by veratrine, indicating that membrane molecules antigenically related to the cytoplasmic protein may also be related to the voltage-gated sodium channel.
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PMID:Possible relationship of brain cytoplasmic tetrodotoxin-sensitive protein to voltage-gated sodium channel shown by monoclonal antibody. 215 3

A parent rhabdomyosarcoma cell line designated SCMC-RM2 was established from bone-marrow tumor cells taken from an 11-year-old girl with an embryonal rhabdomyosarcoma. Subsequently a cloned SCMC-RM2-1 cell line was isolated from a parent line. These cell lines grew as adherent monolayers in liquid culture with a doubling time of 50 and 52 hr, respectively. In addition, colonies were established in soft agar, which grew in a dose-dependent fashion with a cloning efficiency of 0.7 and 0.8%, respectively. Chromosomal analysis showed these cell lines had neither double minutes nor homogeneously staining regions. Chromosome number ranged from 61 to 93, translocation; t(9;13)(p22;q14) was identified, and no alteration of chromosome 2 was observed. Surface membrane antigen profile of parent and cloned lines by using a panel of 24 monoclonal antibodies (MAbs) excluded the possibility of these being neuroblastoma cell lines. In addition, MAbs to the cytoplasmic protein desmin, myoglobin, muscle actin (alpha and gamma) and alpha-sarcomeric actin reacted with these cell lines, SCMC-RM2 and SCMC-RM2-1 being thus identified as rhabdomyosarcoma. Southern blot analyses revealed 8- and 7-fold amplification of the N-myc gene in SCMC-RM2 and SCMC-RM2-1 as compared with the promyelocytic cell line HL60. Over-expression of the N-myc mRNA was noted over control cell lines.
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PMID:Characterization of an embryonal rhabdomyosarcoma cell line showing amplification and over-expression of the N-myc oncogene. 232 48

It has been reported that the ataxin-3 protein containing a polyglutamine sequence in the pathological range (61-84Q) is localized within the nucleus of neuronal cells, whereas ataxin-3 with a normal repeat length (12-37Q) is predominantly a cytoplasmic protein. In this study, the subcellular localization of the full-length ataxin-3 protein with a glutamine sequence in the normal range (Q3KQ22) was analysed in two mammalian cell lines. Using two affinity-purified polyclonal antibodies raised against the N- or C-terminal portion of ataxin-3, the protein was detected predominantly, but not exclusively, in the nucleus of COS-7 as well as neuroblastoma cells by immunofluorescence and confocal laser scanning microscopy (CLSM). The distribution of the protein in these cellular compartments was confirmed by biochemical subcellular fractionations. Furthermore, CLSM revealed that the ataxin-3 protein present in the nucleus of neuroblastoma cells is associated with the inner nuclear matrix. Our results taken together with the finding of a nuclear localization signal in ataxin-3 indicate that the ataxin-3 protein per se translocates to the nucleus and that an expanded glutamine repeat is not essential for this transport.
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PMID:Ataxin-3 is transported into the nucleus and associates with the nuclear matrix. 958 Jun 63

Huntingtin is a cytoplasmic protein of unknown function that associates with vesicle membranes and microtubules. Its protein interactions suggest that huntingtin has a role in endocytosis and organelle transport. In this study we sought to identify factors that regulate the transport of huntingtin in striatal neurons, which are the cells most affected in Huntington's disease. In clonal striatal cells derived from fusions of neuroblastoma and embryonic striatal neurons, huntingtin localization is diffuse and slightly punctate in the cytoplasm. When these neurons were differentiated by treatment with forskolin, huntingtin redistributed to perinuclear regions, discrete puncta along plasma membranes, and branch points and terminal growth cones in neurites. Huntingtin staining overlapped with clathrin, a coat protein involved in endocytosis. Immunoblot analysis of subcellular membrane fractions separated by differential centrifugation confirmed that huntingtin immunoreactivity in differentiated neurons markedly increased in membrane fractions enriched with clathrin and with huntingtin-interacting protein 1. Dopamine treatment altered the subcellular localization of huntingtin and increased its expression in clathrin-enriched membrane fractions. The dopamine-induced changes were blocked by the D1 antagonist SCH 23390 and were absent in a clonal cell line lacking D1 receptors. Results suggest that the transport of huntingtin and its co-expression in clathrin and huntingtin-interacting protein 1-enriched membranes is influenced by activation of adenylyl cyclase and stimulation of dopamine D1 receptors.
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PMID:Forskolin and dopamine D1 receptor activation increase huntingtin's association with endosomes in immortalized neuronal cells of striatal origin. 1036 4

It has been considered that tau protein is mainly a cytoplasmic protein since it is a microtubule associated protein. However, it has also been suggested that tau could be located in the cell nucleus and membrane. In our work, the cellular distribution of tau has been studied by immunofluorescence and western blot analysis, after subcellular fractionation in neuroblastoma cells and in tau-transfected non neural cells using, mainly, two types of tau antibodies; antibody 7.51 (that recognizes tau independent of its phosphorylation level); and antibody Tau-1 (that recognizes tau only in its dephosphorylated form). Also, tau was expressed in COS-1 cells to test for the features involved in the sorting of tau to different cell localizations. Our results show that tau associated to cell membrane has a lower phosphorylation level in its proline-rich region. Additionally, in differentiated neuroblastoma cells, tau phosphorylation, at that region, decreases and the amount of tau associated to cell membrane increases.
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PMID:Tau dephosphorylation at tau-1 site correlates with its association to cell membrane. 1068 3

XIAP (X chromosome-linked inhibitor of apoptosis protein) has been shown to inhibit cell death in a variety of cells. XIAP binds to active caspases, but XIAP also has a carboxy-terminal RING domain that can regulate cell death via protein degradation. Here we have studied the function of full-length and RING-deleted XIAP in mouse sympathetic neurons microinjected with expression plasmids and in neuroblastoma cells stably overexpressing these proteins. Both full-length and RING-deleted XIAP-protected sympathetic neurons against death induced by nerve growth factor (NGF) withdrawal to about the same extent. However, the two proteins were differentially localized in transfected neurons, with RING-deleted XIAP present in the cytoplasm and full-length XIAP found mostly in cytoplasmic protein aggregates, as revealed by transmission electron microscopy. The occurrence of these aggregates was blocked by lactacystin, a proteasome inhibitor. In neuroblastoma cells, RING-deleted XIAP protected against death induced by staurosporine, thapsigargin, or serum withdrawal, whereas full-length XIAP was without effect. Full-length, but not RING-deleted, XIAP was degraded and ubiquitinated in the neuroblastoma cells. The results show that the presence of the RING domain differentially affected the neuroprotective ability of XIAP in sensory neurons and neuroblastoma cells. The RING domain was essentially required for the proteasomal association of XIAP and for its ubiquitination.
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PMID:Regulation of sympathetic neuron and neuroblastoma cell death by XIAP and its association with proteasomes in neural cells. 1269 33

In human tumors, p53 inactivation occurs frequently by mutation, and possibly also by nuclear exclusion of wt p53. First reported by Uta Moll in 1992, p53 "cytoplasmic sequestration" has been thoroughly studied to elucidate molecular mechanism of this process, using neuroblastoma cell lines as model. An American team at the Columbia University has just isolated the cytoplasmic protein Parc [Nikolaev, Cell] which specifically binds to p53 and anchors it, so that the "guardian of the genome" cannot play its role in the nucleus. AntiParc siRNA-manipulation relocates p53 into the nucleus, restitutes a function to p and chemo-radiosensitivity to malignant neuroblasts.
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PMID:[A new view on p53 protein cytoplasmic sequestration]. 1286 54

Parkinson's disease (PD) and other related disorders are characterized by the accumulation of fibrillar aggregates of alpha-synuclein protein (alpha-syn) inside brain cells. It is likely that the formation of alpha-syn aggregates plays a seminal role in the pathogenesis of at least some of these diseases, because two different mutations in the gene encoding alpha-syn have been found in inherited forms of PD. alpha-Syn is mainly expressed by neuronal cells and is generally considered to exist as a cytoplasmic protein. Here, we report the unexpected identification of alpha-syn in conditioned culture media from untransfected and alpha-syn-transfected human neuroblastoma cells, as well as in human cerebrospinal fluid and blood plasma. The method used was immunocapture by using anti-alpha-syn antibodies coupled to magnetic beads, followed by detection on Western blots. In all cases, alpha-syn was identified as a single 15 kDa band, which co-migrated with a recombinant form of the protein and reacted with five different antibodies to alpha-syn. Our findings suggest that cells normally secrete alpha-syn into their surrounding media, both in vitro and in vivo. The detection of extracellular alpha-syn and/or its modified forms in body fluids, particularly in human plasma, offers new opportunities for the development of diagnostic tests for PD and related diseases.
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PMID:Alpha-synuclein implicated in Parkinson's disease is present in extracellular biological fluids, including human plasma. 1451 70

Survivin, a member of the inhibitor of apoptosis (IAP) gene family, plays an important role in both the regulation of cell cycle and the inhibition of apoptosis, and is frequently overexpressed in many tumor types. In neuroblastomas, the expression of survivin correlates with a more aggressive and histologically unfavorable disease. Survivin is predominantly a cytoplasmic protein that is expressed in a cell cycle-dependent manner, increasing in the G2/M phase of the cell cycle followed by a rapid decline in the G1 phase. Recently, the role of survivin in resistance to chemotherapy has become an area of intensive investigation. In this study, we demonstrate a phase-specific resistance due to survivin in staurosporine (STS)-induced apoptosis in the human neuroblastoma cell line SK-N-MC. G2/M-arrested cultures show an upregulation of survivin expression and are more resistant, whereas G1-phase cells that show decreased levels of survivin are more sensitive to apoptosis. Localization studies revealed differences in the distribution of survivin in two synchronized populations, with G1 cells having weakly positive staining confined to the nucleus, in contrast to G2/M cells that depicted a more uniform and intense expression of survivin throughout the cell. In our experimental system, STS induced apoptosis through the mitochondrial-caspase 9-mediated pathway. Retention of survivin in G1 cells by inhibition of the ubiquitin-proteosome pathway or inhibition of caspase 9 protected the cells against apoptosis. Our data suggest that survivin exerts its antiapoptotic effect by inhibiting caspase 9 activity, an important event in STS-mediated apoptosis. In context with cell cycle-dependent responses to chemotherapy, the data from this study suggest the possibility of exploiting the survivin pathway for inducing apoptosis in tumor cells.
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PMID:Upregulation of survivin in G2/M cells and inhibition of caspase 9 activity enhances resistance in staurosporine-induced apoptosis. 1506 69


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