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 ubiquitin-binding Rpn10 protein serves as an ubiquitin receptor that delivers client proteins to the 26S proteasome, the protein degradation complex. It has been suggested that the ubiquitin-dependent protein degradation is critical for neuronal differentiation and for preventing neurodegenerative diseases. Our previous study indicated the importance of Rpn10 in control of cellular differentiation (Shimada et al., Mol Biol Cell 17:5356-5371, 2006), though the functional relevance of Rpn10 in neuronal cell differentiation remains a mystery to be uncovered. In the present study, we have examined the level of Rpn10 in a proteasome-containing high molecular weight (HMW) protein fraction prepared from the mouse neuroblastoma cell line Neuro2a. We here report that the protein level of Rpn10 in HMW fraction from un-differentiated Neuro2a cells was significantly lower than that of other cultured cell lines. We have found that retinoic acid-induced neural differentiation of Neuro2a cells significantly stimulates the incorporation of Rpn10 into HMW fractions, although the amounts of 26S proteasome subunits were not changed. Our findings provide the first evidence that the modulation of Rpn10 is linked to the control of retinoic acid-induced differentiation of neuroblastoma cells.
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PMID:Association of Rpn10 with high molecular weight complex is enhanced during retinoic acid-induced differentiation of neuroblastoma cells. 1766 54

Neuronal Lewy body-like hyaline inclusions (LBHI) and astrocytic hyaline inclusions (Ast-HI) containing mutant Cu/Zn superoxide dismutase 1 (SOD1) are morphological hallmarks of familial amyotrophic lateral sclerosis (FALS) associated with mutant SOD1. However, the mechanisms by which mutant SOD1 contributes to formation of LBHI/Ast-HI in FALS remain poorly defined. Here, we report induction of LBHI/Ast-HI-like hyaline inclusions (LHIs) in vitro by ER stress in neuroblastoma cells. These LHI closely resemble LBHI/Ast-HI in patients with SOD1-linked FALS. LHI and LBHI/Ast-HI share the following features: 1) eosinophilic staining with a pale core, 2) SOD1, ubiquitin and ER resident protein (KDEL) positivity and 3) the presence of approximately 15-25 nm granule-coated fibrils, which are morphological hallmark of mutant SOD1-linked FALS. Moreover, in spinal cord neurons of L84V SOD1 transgenic mice at presymptomatic stage, we observed aberrant aggregation of ER and numerous free ribosomes associated with abnormal inclusion-like structures, presumably early stage neuronal LBHI. We conclude that the LBHI/Ast-HI seen in human patients with mutant SOD1-linked FALS may arise from ER dysfunction.
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PMID:An in vitro model for Lewy body-like hyaline inclusion/astrocytic hyaline inclusion: induction by ER stress with an ALS-linked SOD1 mutation. 1792 78

The neural cell adhesion molecule NCAM plays an important role during neural development and in the adult brain. To study the intracellular trafficking of NCAM in neurons, two major isoforms, NCAM140 or NCAM180, were expressed in primary cortical neurons and in the rat B35 neuroblastoma cell line. NCAM was endocytosed and subsequently recycled to the plasma membrane, whereas only a minor fraction was degraded in lysosomes. In cortical neurons, endocytosis of NCAM was detected in the soma, neurites and growth cones in a developmentally regulated fashion. Furthermore, we found that NCAM is mono-ubiquitylated at the plasma membrane and endocytosis was significantly increased in cells overexpressing ubiquitin. Therefore, we propose that ubiquitylation represents an endocytosis signal for NCAM.
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PMID:NCAM is ubiquitylated, endocytosed and recycled in neurons. 1797 10

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disorder characterized by the selective loss of motor neurons from the spinal cord and brain. About 10% of ALS cases are familial (FALS), and in 20% of these cases the disease has been linked to mutations in the Cu,Zn-SOD1 gene. Although the molecular mechanisms causing these forms of ALS are still unclear, evidence has been provided that motor neurons injuries associated with mutant superoxide dismutase (SOD1)-related FALS result from a toxic gain-in-fuction of the mutated enzyme. To understand better the role of these mutations in the pathophysiology of FALS we have compared the pattern of proteins expressed in human neuroblastoma SH-SY5Y cell line with those of cell lines transfected with plasmids expressing the wild-type human SOD1 and the H46R and G93A mutants. 2-DE coupled to MALDI-TOF-MS were the proteomic tools used for identification of differentially expressed proteins. These included cytoskeletal proteins, proteins that regulate energetic metabolism and intracellular redox conditions, and the ubiquitin proteasome system. The proteomic approach allowed to expand the knowledge on the pattern of proteins, with altered expression, which we should focus on, for a better understanding of the possible mechanism involved in mutated-SOD1 toxicity. The cellular models considered in this work have also evidenced biochemical characteristics common to other SOD1-mutated cellular lines connected to the pathogenesis of ALS.
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PMID:2-DE and MALDI-TOF-MS for a comparative analysis of proteins expressed in different cellular models of amyotrophic lateral sclerosis. 1797 59

The beacon gene is involved in the regulation of energy metabolism, food intake, and obesity. We localized its gene product, beacon-/ubiquitin 5-like immunoreactivity in brains of normal-weight, non-psychotic individuals, adipose (BMI over 32), non-psychotic individuals, and haloperidol-treated schizophrenics. The protein was found to be highly expressed in many neurons of the paraventricular and supraoptic hypothalamic nuclei. Besides, it was detected in neurons of other hypothalamic areas (suprachiasmatic, arcuate, and ventromedial nuclei) as well as outside the hypothalamus (Nuc. basalis Meynert, thalamus, hippocampus, and some neocortical areas). A morphometric analysis of beacon-immunoreactive hypothalamic and neocortical neurons revealed that compared to normal-weight controls in haloperidol-treated schizophrenics, there was a significant increase of protein-expressing supraoptic, paraventricular, and orbitofrontal neurons. However, a significant increase in beacon-expressing supraoptic neurons was also seen in adipose, non-psychotic individuals in comparison with normal-weight controls. Haloperidol at different doses has no effect on beacon expression in SHSY5Y neuroblastoma cells, which makes the assumption unlikely that haloperidol per se is responsible for the increased neuronal expression of the peptide in schizophrenics. In rats with a neonatal lesion of the ventral hippocampus (a widely used animal model of schizophrenia), we found an increased neuronal expression of beacon in the paraventricular and supraoptic nuclei. We suppose that elevated hypothalamic expression of beacon-like protein in non-obese schizophrenics is not primarily related to metabolic alterations, but to a certain role in schizophrenia, which is possibly unrelated to aspects of weight gain and obesity. The latter assumption finds some support by data obtained in rats with ventral hippocampus lesion.
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PMID:Beacon-like/ubiquitin-5-like immunoreactivity is highly expressed in human hypothalamus and increased in haloperidol-treated schizophrenics and a rat model of schizophrenia. 1819 6

NEDL1 (NEDD4-like ubiquitin protein ligase-1) is a newly identified HECT-type E3 ubiquitin protein ligase highly expressed in favorable neuroblastomas as compared with unfavorable ones. In this study, we found that NEDL1 cooperates with p53 to induce apoptosis. During cisplatin (CDDP)-mediated apoptosis in neuroblastoma SH-SY5Y cells, p53 was induced to accumulate in association with an increase in expression levels of NEDL1. Enforced expression of NEDL1 resulted in a decrease in number of G418-resistant colonies in SH-SY5Y and U2OS cells bearing wild-type p53, whereas NEDL1 had undetectable effect on p53-deficient H1299 and SAOS-2 cells. Similarly, enforced expression of NEDL1 increased number of U2OS cells with sub-G1 DNA content. Co-immunoprecipitation and in vitro binding assays revealed that NEDL1 binds to the COOH-terminal region of p53. Luciferase reporter assay showed that NEDL1 has an ability to enhance the transcriptional activity of p53. Small interfering RNA-mediated knockdown of the endogenous NEDL1 conferred the resistance of U2OS cells to adriamycin. It is noteworthy that NEDL1 enhanced pro-apoptotic activity of p53 in its catalytic activity-independent manner. Taken together, our present findings suggest that functional interaction of NEDL1 with p53 might contribute to the induction of apoptosis in cancerous cells bearing wild-type p53.
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PMID:A novel HECT-type E3 ubiquitin protein ligase NEDL1 enhances the p53-mediated apoptotic cell death in its catalytic activity-independent manner. 1822 81

The role of amyloid-beta protein (Abeta) in the pathogenesis of Alzheimer's disease (AD) has been widely investigated and amyloid aggregates are considered a major cause of neuronal dysfunction. Increasing evidence has identified a correlation between this protein and the proteasome, the cellular proteolytic machinery, in particular the ubiquitin-proteasome system. The 20S proteasome is the catalytic core of a complex, known as 26S proteasome, and is the main responsible for the clearance of misfolded and oxidized proteins. In this work we have investigated the effects of different assembly states of two major amyloid peptides, Abeta (1-40) and Abeta (1-42) on the 20S proteasome functionality and on the ubiquitin-dependent pathway of protein degradation. In particular, we have tested proteasome activities after Abeta treatment on purified 20S complexes and on lysates of a human neuroblastoma cell line. Our findings show a significant decrease in proteasome activity, more evident in cell lysates than in isolated complexes, and an increased amount of ubiquitin-protein conjugates and of a known proteasome substrate (p27). Furthermore, the altered proteasome functionality is not associated with a decrease in cell viability, but is linked with increased levels of protein oxidation.
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PMID:Amyloid peptides in different assembly states and related effects on isolated and cellular proteasomes. 1840 Feb 14

A number of studies have associated the S18Y polymorphic variant of UCH-L1 with protection from sporadic Parkinson's Disease (PD). The mechanism involved in this protective function is unknown, but has generally been assumed to be linked to the ubiquitin-proteasome system (UPS). In the current study, we have investigated the effects of overexpression of UCH-L1 and its variants, including S18Y, in neuronal cells. We find that S18Y, but not WT, UCH-L1 confers a specific antioxidant protective function when expressed at physiological levels in human neuroblastoma cells and primary cortical neurons. In contrast, neither WT nor S18Y UCH-L1 appear to directly impact the proteasome, although they both lead to stabilization of free ubiquitin. Lack of WT mouse UCH-L1 in neurons derived from gad mice led to a decrease of free ubiquitin, but no overall decrease in UPS function or enhanced sensitivity to oxidative stress. We conclude that the S18Y variant of UCH-L1 confers a novel antioxidant function that is not present in the WT form and that this function may underlie the protective effects of this variant in certain PD populations. Our results furthermore provide indirect evidence for the importance of oxidative stress as a pathogenetic factor in certain forms of sporadic PD.
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PMID:The S18Y polymorphic variant of UCH-L1 confers an antioxidant function to neuronal cells. 1841 Dec 55

Elk-1, an ETS domain transcription factor of the TCF (ternary complex factor) subfamily, is known to be involved in the regulation of immediate-early genes such as c-fos upon mitogen activation, and thus commonly implied in cell proliferation. Early growth response-1, Egr-1, which was known to be an immediate-early gene, has recently been shown to be pro-apoptotic for SH-SY5Y neuroblastoma cells. In that respect, it was not clear whether Elk-1 would activate or repress from this promoter, since Elk-1 is mostly associated with proliferation and not apoptosis. In this study, we wanted to address whether Elk-1 activates or represses egr-1 promoter in neuroblastoma cells, and using a combination of RNA interference and reporter analyses, we present evidence that egr-1 gene is repressed by Elk-1 in normally cycling SH-SY5Y neuroblastoma cell line in a SUMO (small ubiquitin-related modifier)-dependent manner, a potential mechanism used by these cells to bypass apoptosis.
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PMID:Wildtype Elk-1, but not a SUMOylation mutant, represses egr-1 expression in SH-SY5Y neuroblastomas. 1843 15

A common feature of tumor cells is the aberrant expression of ion channels on their plasma membrane. The molecular mechanisms regulating ion channel expression in cancer cells are still poorly known. K(+) channels that belong to the human ether-a-go-go-related gene 1 (herg1) family are frequently misexpressed in cancer cells compared to their healthy counterparts. We describe here a posttranslational mechanism for the regulation of hERG1 channel surface expression in cancer cells. This mechanism is based on the activity of hERG1 isoforms containing the USO exon. These isoforms (i) are frequently overexpressed in human cancers, (ii) are retained in the endoplasmic reticulum, and (iii) form heterotetramers with different proteins of the hERG family. (iv) The USO-containing heterotetramers are retained intracellularly and undergo ubiquitin-dependent degradation. This process results in decreased hERG1 current (I(hERG1)) density. We detailed such a mechanism in heterologous systems and confirmed its functioning in tumor cells that endogenously express hERG1 proteins. The silencing of USO-containing hERG1 isoforms induces a higher I(hERG1) density in tumors, an effect that apparently regulates neurite outgrowth in neuroblastoma cells and apoptosis in leukemia cells.
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PMID:Identification of a posttranslational mechanism for the regulation of hERG1 K+ channel expression and hERG1 current density in tumor cells. 1855 21


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