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)

Previous studies showed that the core promoter of the mouse cAMP-dependent protein kinase regulatory subunit type II beta (RII beta) gene was composed of two functional elements. One element was GC rich and bound the Sp1 transcription factor. The second element contained a helix-loop-helix (HLH)-motif. Each element conferred transcriptional activity when inserted upstream of a reporter gene, chloramphenicol acetyltransferase and transfected into mouse NB2a neuroblastoma cells and Chinese hamster ovary (CHO) cells. The core promoter was further characterized by mutational analysis using electrophoretic mobility shift assays and by transfection into CHO and NB2a cells. Electrophoretic mobility shift assays showed that the HLH-consensus motif, CACGTG, present in the RII beta gene bound nuclear factors present in NB2a and CHO cells. Mutations in the HLH-core motif decreased the binding of these factors and reduced the transcriptional activity of constructs containing the chloramphenicol acetyltransferase reporter when transfected into these cells. The results showed that the central nucleotides as well as the adjacent bases were important for the interaction with the nuclear binding factors. UV cross-linking, Southwestern blot analysis, and interference of the mobility shift patterns by specific antisera directed against USF and c-Myc indicated that both of these transcription factors were forming complexes with the HLH-consensus motif. The results suggest that RII beta transcription may be regulated, in part, by USF and c-Myc in NB2a and CHO cells.
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PMID:Association of USF and c-Myc with a helix-loop-helix-consensus motif in the core promoter of the murine type II beta regulatory subunit gene of cyclic adenosine 3', 5'-monophosphate-dependent protein kinase. 783 49

The expression of plasma membrane Ca2+ pump (PMCA) is regulated by various hormones or agonists via multiple second messenger pathways. Two different 5' segments of the PMCA1 gene (isoform 1) were cloned from a mouse genomic library. While one segment contained the 3' end of intron 1 and exon 2, the other segment was found to encompass the 5'-flanking region of the gene, exon 1, and the 5' portion of intron 1. Sequence analysis of the 5'-flanking region suggested the presence of the putative promoter. Four sites for initiation of transcription (spanning 64 bp) were identified by RNase protection assay and primer extension analysis. The promoter region was very GC-rich, contained no "TATA box," but had a "CAAT box" at -51. Comparison of sequence with known cis-regulatory motifs disclosed that the 5'-flanking region has a number of potential regulatory elements including an AP-1 site at -354, AP-2 binding sites at -267 and -123, Sp1 binding sites at -127, -111, and +3, and a cyclic AMP response element binding protein site at -67. To demonstrate promoter activity, a segment containing 611 bp of the promoter region (from -442 to +169) was subcloned in front of a promoterless chloramphenicol acetyltransferase (CAT) gene. This segment was able to drive the expression of chloramphenicol acetyltransferase in transient transfections of mouse (or human) neuroblastoma cells as well as rat aortic endothelial cells. Deletion analysis demonstrated that a fragment from -256 to +169 showed strong promoter activity, while a fragment from -117 to +169 had CAT activity that was not different from the vector control. The promoter was stimulated threefold by phorbol ester and twofold by cyclic AMP. These results provide further proof indicating up-regulation of the PMCA1 gene by multiple second messenger pathways.
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PMID:The mouse plasma membrane Ca2+ pump isoform 1 promoter: cloning and characterization. 784 Jun 30

Our studies in the NG108-15 neuroblastoma x glioma cell line previously showed that the molecular chaperonin, Hsc70, is an ethanol-responsive gene (EtRG) regulated at the level of transcription by ethanol. We recently identified two related molecular chaperonins, GRP94 and GRP78, as EtRGs with GRP94 mRNA abundance being induced by ethanol more than three-fold vs. control. Stable transfection studies show that GRP78 transcription is also regulated by ethanol and that ethanol also potentiates GRP78 induction by classical inducing agents such as tunicamycin. Recently, we have found that ethanol induction of Hsc70 may require cis-acting promoter sequences recognized by the DNA-binding protein Sp1. Chronic ethanol exposure does not alter Sp1 DNA-binding activity, thus suggesting a possible ethanol-induced post-translational modification that activates Sp1 function. We predict that the molecular mechanisms underlying ethanol regulation of Hsc70, GRP94 and GRP78 may be similar since they have related functions. GRP94 and GRP78 (GRP94/78) are known to be induced by agents which inhibit glycoprotein processing or deplete endoplasmic reticulum stores of calcium. In turn, induction of GRP78 expression is known to selectively alter the transport of glycoproteins and produce "tolerance" to depletion of sequestered intracellular calcium. The regulation of these genes by ethanol could thus relate to the known effects of ethanol on calcium homeostasis and protein trafficking. The actions of ethanol on chaperonin gene expression may have important mechanistic implications for CNS adaptation to ethanol, particularly if other EtRGs share the same regulatory mechanisms.
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PMID:Effects of alcohol on gene expression in neural cells. 803 72

In human astrocytoma and neuroblastoma cell lines tumour necrosis factor alpha (TNF alpha) and interleukin 1 beta (IL-1 beta) induced NFKB and an additional KB-specific protein of approximately 80 K to bind the HIV-1 enhancer. One nucleoprotein complex contained prototypical NFKB comprising of p50 and p65 subunits and a second contained the p65 subunit and an 80 K factor, p80. Over a 24 hr period of cytokine stimulation the p50/p65 complex of NFKB was present in the nucleus whilst the second complex declined in abundance after two hours due to the decline of p80. In unstimulated cells, DNAse I footprinting revealed a previously unidentified octamer-like binding site in the negative regulatory element (NRE) of the HIV-1 long terminal repeat (LTR) which specifically bound protein factors present in human astrocytoma, neuroblastoma and murine oligodendroglioma cell lines. A second unique motif, also in the NRE, was observed with extracts from one human neuroblastoma cell line and a murine oligodendroglioma. Footprinting analysis also confirmed that Sp1, TATA, Site A and Site B motifs of the LTR were occupied by nuclear factors present in neural cells.
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PMID:Tumour necrosis factor alpha and interleukin-1 beta induce specific subunits of NFKB to bind the HIV-1 enhancer: characterisation of transcription factors controlling human immunodeficiency virus type 1 gene expression in neural cells. 807 13

The minimum requirement of an enhancer for the human choline acetyltransferase (ChAT) gene was analyzed by mutagenesis and protein-DNA interaction studies. A series of deletion and site-specific mutants were expressed transiently in a rat cholinergic neuroblastoma cell, NS20Y. The results revealed that the distal region between -970 and -941 base pairs (bp) from the transcription start site is essential for efficient transcription of the human ChAT gene. Two GC box-like sequences were located within this region, and they were shown to bind purified Sp1 transcription factor by footprinting and gel retardation analyses. This sequence, however, has an orientational effect and is located approximately 1000 bp from the transcription start site, unusual for the conventional GC box sequence. Furthermore, the sequence between these GC box-like sequences is shown to bind another novel trans-acting factor by gel retardation assay and to be necessary for efficient enhancer activity. On the other hand, gel retardation assays using a nuclear extract from Drosophila SL2 cells suggested that non-Sp1 trans-acting factors could also participate in the enhancing activity of this element. Taken together, the results demonstrate that two GC box-like sequences and another trans-acting factor-binding sequence located between -970 and -941 bp act coordinately and are essential for efficient transcription of this low expressed human ChAT gene.
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PMID:Enhancer containing unusual GC box-like sequences on the human choline acetyltransferase gene. 811 17

During functional neuronal differentiation of human SH-SY5Y neuroblastoma cells, induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), the mRNA expression of c-fos and c-jun displayed a synchronous and biphasic type of induction for both mRNAs, with an early transient (30 to 120 min) and a later (> 8 h) more persistent increase. This was coupled to increased in vitro DNA binding activity of cFos/cJun AP-1 heterodimers in SH-SY5Y nuclear extracts using the electrophoretic mobility shift assay. Functional AP-1 activity was demonstrated in differentiating SH-SY5Y cells by transient transfection assays using a TPA-responsive reporter plasmid. The second expression phase of these protooncogenes was paralleled by a sustained induction of neuronal differentiation markers, as exemplified by growth-associated protein 43 and neuropeptide tyrosine (NPY) mRNAs. DNA-protein interaction between an evolutionarily conserved region (-73 to -45) of the human NPY promoter, containing potential binding sites for AP-1, AP-2, and Sp1, and nuclear extracts prepared from untreated and TPA-treated SH-SY5Y cells revealed one complex (CI) that was unaffected and three complexes (CII to CIV) that were induced by TPA treatment. Competition for DNA binding using AP-1, AP-2, and Sp1 consensus sequences and an anti-cJun antibody, respectively, revealed cooperative interactions between AP-1, AP-2, and Sp1 transcription factors and the NPY promoter. In addition, TPA-mediated induction of AP-2 DNA binding activity to the NPY promoter was not dependent on increased AP-2 mRNA expression. This high degree of complexity presumably involved in NPY gene expression during neuronal differentiation of SH-SY5Y cells suggests productive cooperative interactions between multiple transcription factors.
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PMID:Activation of the human NPY gene during neuroblastoma cell differentiation: induced transcriptional activities of AP-1 and AP-2. 812 90

We have isolated genomic clones which encode the promoter and flanking region of human nonmuscle myosin heavy chain (MHC)-A. The sequence of this region shows many features typical of a housekeeping gene; there is no TATA element and no functional CAAT box. The GC content is high, having an average GC content of 74% in the 600 base pairs (bp) surrounding the transcriptional start sites, and multiple GC boxes (putative Sp1 binding sites) are present. A number of nucleotide sites are utilized for the initiation of transcription. Promoter activity was monitored using luciferase as a reporter following transient transfection into NIH 3T3 cells. Analysis of 5' and 3' deletion mutants in the promoter region defines the core promoter as extending from nucleotide -112 to +61, where +1 is a major transcriptional start site. An essential sequence for core promoter activity resides in the 36-bp region from -77 to -112 which includes a single potential AP-2 binding site and a single potential Sp1 binding site. The region just downstream from the transcriptional start site (between +62 and +257) was found to be involved in cell type-specific activation of nonmuscle MHC-A gene expression. The increase in luciferase activity due to this proximal downstream region is approximately 15-fold in NIH 3T3 cells, but no increase was observed in C2C12 myotubes and neuroblastoma cells. This 196-bp region, which consists of 100 bp from exon 1 and 96 bp from intron 1, functions in a position- and orientation-dependent manner. Quantitation of luciferase mRNA content driven by the MHC-A promoter, using both competitive polymerase chain reaction and RNase protection assays, revealed that the increase seen in luciferase mRNA due to the 196-bp fragment is approximately 5-fold in NIH 3T3 cells. This only accounts for about one-third of the total increase seen in luciferase activity (protein amounts). Thus, this proximal downstream region appears to activate gene expression in NIH 3T3 cells via both pretranslational (transcription and/or mRNA stability) and translational mechanisms.
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PMID:Evidence for an internal regulatory region in a human nonmuscle myosin heavy chain gene. 819 47

We show that expression of the p34cdc2 and cyclin A genes is induced by interleukin-2 in normal human T cells and present evidence to support the idea that these genes are deregulated in leukemic T cells. Our DNA sequencing data indicate that the promoter region of the p34cdc2 gene contains putative E2F-like binding sites which are recognized by Rb and binding sites for c-myb, Sp1, and ATF, and that the promoter region of the cyclin A gene contains binding sites for p53, Sp1, and ATF. In this study we focus on the effect of p53 and Rb on these cell cycle-regulatory genes. Cotransfection of Y79 human retinoblastoma cells with a p34cdc2 promoter-luciferase expression vector and a plasmid expressing the retinoblastoma gene (RB) indicated that RB suppresses p34cdc2 expression. Cotransfection of B104 rat neuroblastoma cells with a cyclin A promoter-luciferase expression vector and a plasmid expressing the normal or mutant p53 indicated that only the normal p53 suppresses cyclin A expression. In normal T cells, PHA stimulation reduces the amount of complexes in the p34cdc2 promoter between the E2F-like binding site and the RB gene product. These complexes were not detected in leukemic T cells. Our data support the idea that tumor suppressors modulate the expression of cell cycle-regulatory genes: RB regulates p34cdc2 expression and p53 regulates cyclin A expression.
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PMID:Effect of tumor suppressors on cell cycle-regulatory genes: RB suppresses p34cdc2 expression and normal p53 suppresses cyclin A expression. 827 2

We investigated the cis-acting sequences involved in the expression of the human aldolase C gene by transient transfections into human neuroblastoma cells (SKNBE). We demonstrate that 420 bp of the 5'-flanking DNA direct at high efficiency the transcription of the CAT reporter gene. A deletion between -420 bp and -164 bp causes a 60% decrease of CAT activity. Gel shift and DNase I footprinting analyses revealed four protected elements: A, B, C and D. Competition analyses indicate that Sp1 or factors sharing a similar sequence specificity bind to elements A and B, but not to elements C and D. Sequence analysis shows a half palindromic ERE motif (GGTCA), in elements B and D. Region D binds a transactivating factor which appears also essential to stabilize the initiation complex.
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PMID:Cis-acting elements in the promoter region of the human aldolase C gene. 834 72

We have examined cis-elements and trans-acting factors that regulate transcription of the human cholecystokinin (CCK) gene. Transient expression of CCK promoter deletion constructs in human SK-N-MC neuroblastoma cells depicted positive cis-elements between the positions -100 to -92, -84 to -74, and -58 to -37, 5' to the transcription initiation site. Correspondingly, DNase I protection analysis showed that transacting factors bound to elements within these regions. The sequences encompass a putative basic helix-loop-helix leucine zipper (bHLH-ZIP) element, an Sp1 element, and a combined cAMP- and TPA-responsive element (CRE/TRE) at positions -97 to -92, -39 to -34, and -80 to -73, respectively. Mobility and supershift assays demonstrated that upstream stimulatory factor (USF) and Sp1 bind to the former elements and competition experiments confirmed that CREB/ATF and AP-1 bind to the CRE/TRE element. Mutation of the bHLH-ZIP and CRE/TRE elements decreased the activity of the promoter by 65% and 42%, respectively. The activity of the promoter was increased six- and two-fold after stimulation with forskolin and TPA, respectively. Stimulation was eliminated after mutation of the CRE/TRE element. Co-transfection experiments with pRSV-c-jun, pSV-fos, and pRC-RSV-CREB constructs showed that jun, CREB, and AP-1 stimulate transcription. We conclude that USF, Sp1, and members of the CREB/ATF and AP-1 family of transcription factors are the major determinants of CCK gene transcription.
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PMID:Transcriptional regulation of the human cholecystokinin gene: composite action of upstream stimulatory factor, Sp1, and members of the CREB/ATF-AP-1 family of transcription factors. 856 97


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