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)

c-Jun, a crucial component of the dimeric transcription factor activating protein 1 (AP-1), can regulate apoptosis induced by oxidative stress and has been implicated in neuronal differentiation, but the mechanisms are largely unknown. We found that specific inhibition of transcription or stable transfection with cDNA encoding dominant-negative c-Jun sensitized SH-SY5Y neuroblastoma cells (TAM-67 cells) to apoptosis induced by the nitric oxide (NO) donor sodium nitroprusside or SIN-1. TAM-67 cells also became refractory to nerve growth factor (NGF)-induced neuronal differentiation. Dominant-negative c-Jun abolished expression of a 140-kDa neural cell adhesion molecule (NCAM140) and dramatically enhanced the expression of NCAM180 in TAM-67 cells. Inhibition of c-Jun in TAM-67 cells also resulted in a corresponding decrease in the amount of NCAM140 mRNA and an increase in the amount of NCAM180 mRNA. Reexpression of NCAM140 in TAM-67 cells restored NGF-induced neuronal differentiation and resistance to NO-induced apoptosis. Our results show that c-Jun/AP-1, through up-regulation of NCAM140, plays an important role in both NGF-induced neuronal differentiation and resistance to apoptosis induced by NO in neuroblastoma cells. As NCAM140 and NCAM180 are translated from differentially spliced mRNAs transcribed from the same gene, alternative splicing of NCAM pre-mRNA (and consequently the synthesis of the smaller NCAM140 species) appears to be regulated by c-Jun/AP-1.
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PMID:Neuronal differentiation and protection from nitric oxide-induced apoptosis require c-Jun-dependent expression of NCAM140. 1210 Dec 31

Induction of cyclooxygenase-2 (COX-2) in the brain of people infected with human immunodeficiency virus type 1 (HIV-1) has been proposed as a cause of cognitive impairment in AIDS dementia. Here, we have analyzed the molecular mechanism by which its induction takes place in neuroblastoma cells. The HIV-1 envelope protein gp120 was able to induce COX-2 mRNA and protein in several human neuroblastoma cell lines, which express CXCR4 and CCR5 but not CD4. Moreover, gp120 induces COX-2 promoter transcription. Sequential deletions of the promoter show that deletion of a distal nuclear factor-kappaB (NF-kappaB) site abrogated gp120-dependent transcription. More importantly, overexpression of NF-kappaB inhibitory subunit, IkappaBalpha, completely abrogated gp120-induced COX-2 activity. However, transfection of p65/relA NF-kappaB was not enough to induce COX-2 transcription, suggesting that NF-kappaB was necessary but not sufficient to control COX-2 transcription induced by gp120. In addition to NF-kappaB, activating protein-1 (AP-1) but not nuclear factor of activated T cells (NFAT)-dependent transcription was induced by gp120. Transfection of a dominant negative mutant c-Jun protein, TAM-67, efficiently blocked the induction of COX-2 promoter by gp120, confirming AP-1 requirement. Moreover, gp120 rapidly activates the c-Jun amino-terminal kinase (JNK) and p38 mitogen-activated protein kinase phosphorylation. The importance of NF-kappaB and AP-1 in COX-2 promoter and protein induction was corroborated by using pharmacological NF-kappaB, p38 and JNK inhibitors.
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PMID:Human immunodeficiency virus type 1 envelope glycoprotein 120 induces cyclooxygenase-2 expression in neuroblastoma cells through a nuclear factor-kappaB and activating protein-1 mediated mechanism. 1600 69

In the present paper, a system for on-line preconcentration and determination of copper by flame atomic absorption spectrometry (FAAS) was developed. It was based on solid phase extraction of copper(II) ions on a minicolumn of Amberlite XAD-2 loaded with 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM). The optimisation process was carried out using Doehlert designs. Four variables (sampling flow rate, SR; elution flow rate, buffer concentration, BC; and pH) were regarded as factors in the optimisation. The parameter "sensitivity efficiency (SE)" proposed in this paper, and defined as the analytical signal obtained for an on-line enrichment system for a preconcentration time of 1 min was used as analytical response in the optimisation process. Using the established experimental conditions, the proposed on-line system allowed determination of copper with detection limit (3sigma/S) of 0.23 mug l(-1), and a precision (repeatability), calculated as relative standard deviation (R.S.D.) of 3.9 and 3.7% for copper concentration of 5.00 and 20.00 mug l(-1), respectively. The preconcentration factor obtained is 62. The recovery achieved for copper determination in presence of several cations demonstrated that this has enough selectivity for analysis of food samples. The robustness of the proposed system was also evaluated. The accuracy was confirmed by analysis of the following certified reference materials (CRMs): Rice flour NIES 10a, Spinach leaves NIST 1570a, Apples leaves NIST 1515 and Orchard leaves NBS 1571. This procedure was applied for copper determination in natural food samples.
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PMID:Application of Doehlert designs for optimisation of an on-line preconcentration system for copper determination by flame atomic absorption spectrometry. 1896 89