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)

To investigate the regulatory processes involved in the expression of the D2 dopamine receptor gene, a rat genomic clone was isolated using a 21-mer oligonucleotide probe made of exon 1 sequences. A 1.3-kb region including all of exon 1, its 5'-flanking region, and part of intron 1 was sequenced. S1 nuclease analysis indicated three consecutive nucleotides as the main transcription start sites; several weaker sites were also noted between 321 and 363 nucleotides upstream from the 3' end of exon 1. The promoter region lacks TATA and CAAT boxes and is rich in G+C content with several putative Sp1 binding sites. Transient expression assays using chimeric constructs of D2 promoter deletion mutants-chloramphenicol acetyl-transferase gene in the neuroblastoma cell line NB41A3 which expresses D2 binding sites indicated strong transcription enhancing activity between nucleotides -75 and -30 and silencing activity between nucleotides -217 and -76. DNase I footprinting studies using nuclear extract from NB41A3 suggested Sp1 binding to its consensus sequence at nucleotide -48 but inhibition of Sp1 binding at nucleotide -86 by the extract. The D2 promoter could not induce transcription of the heterologous CAT gene in C6 glioma, embryonal NIH 3T3, or hepatic Hep G2 cells. It is concluded that the rat D2 gene shares with the human D1A dopamine receptor gene several features typical of "housekeeping" genes but they are both tissue-specific, regulated genes. Unlike the D1A gene, however, the D2 gene has a strong preference for transcription initiation to three consecutive nucleotides.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Analysis of the promoter region of the rat D2 dopamine receptor gene. 139 Jun 23

The 5'-terminal region of the rat gene for the neuron-specific phosphoprotein, synapsin I, was isolated and sequenced. It comprises 1472 nucleotides (nt) of 5'-flanking sequence, 507 nt of the first exon, and 242 nt of the first intron. A single transcription start site was mapped by primer extension and S1 nuclease analysis. A sequence of 340 nt upstream from the transcription start site and the first exon are G+C-rich and enriched in CpG dinucleotides, resembling a CpG island. The 5'-flanking sequence lacks TATA and CAAT consensus elements but contains a consensus motif for the cAMP-responsive element. Furthermore, we notice two potential consensus motifs which are also found in corresponding positions in the genes for the nerve growth factor receptor and the 68-kDa neurofilament protein. The 5'-terminal region of the human synapsin I gene was also cloned and sequenced. A high degree of sequence conservation between rat and human is found in the upstream 340 nt that coincides precisely with the G+C-rich domain and includes the consensus elements, and throughout the first exon including the untranslated sequence. Sequence conservation is also observed further upstream and at the beginning of the first intron. In a transient chloramphenicol acetyltransferase expression assay, 5'-flanking sequences of the rat synapsin I gene function as strong promoters in neuroblastoma cells, but not in fibroblastoid cells. 225 nt of 5'-flanking sequence and 105 nt of 5'-untranslated sequence are sufficient for cell-type specific transcription in this assay.
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PMID:The 5'-flanking region of the synapsin I gene. A G+C-rich, TATA- and CAAT-less, phylogenetically conserved sequence with cell type-specific promoter function. 211 19

Retinoic acid (RA) induced differentiation of SH-SY5Y neuroblastoma cells is associated with more than a tenfold induction of total Alzheimer's disease beta A4 amyloid protein precursor (APP) mRNA as analyzed by Northern blot hybridisation. S1 nuclease protection experiments reveal that the splicing pattern of these differentiated cells is altered in favor of APP695 mRNA, coding for the shortest amyloidogenic beta A4 amyloid precursor protein. Induction of differentiation of SH-SY5Y cells with NGF leads to a fivefold increase of total APP mRNA without change in the splicing pattern. This suggests that RA but not NGF induces factor(s) which are responsible for an APP hnRNA splicing favoring APP695 mRNA.
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PMID:Retinoic acid induced differentiated neuroblastoma cells show increased expression of the beta A4 amyloid gene of Alzheimer's disease and an altered splicing pattern. 220 13

A cDNA library was efficiently synthesized from mouse neuroblastoma poly(A)+RNA. Several modifications of the oligo(dC)(dG) tailing procedure were used. After first strand synthesis, a dATP tail was added to the 3'-end of the cDNA. The second strand was primed for synthesis with oligo(dT). Blunt ends were produced on the cDNA by treatment with S1 nuclease. Size-enriched fractions of high molecular weight DNAs were obtained by passing the cDNA over a Sepharose CL-4B column. The optimal tailing time for each cDNA fraction was individually tested. Tailing reactions used terminal deoxynucleotidyl transferase and annealing reactions used a (G)-tailed Pst I cut pBR322. E. coli K12 RR1 cells were transformed and 2.5-5 X 10(6) transformants per microgram cDNA insert were obtained for each size fraction. The transformants had an average insert size of 1200 base pairs and were 98% ampicillin sensitive. Our modifications in the method for cDNA library synthesis had 3 advantages. (1) Homopolymer-primed cDNA treated with S1 nuclease allowed the blunt ends to be tailed synchronously. This allowed a higher transformation efficiency without loss of 5'-sequences. (2) Time tailing determined the most efficient tail length and optimized the transformation efficiency in each size fraction. (3) A Sephadex G-50 mini-column was used to desalt and dry nitrogen was used to concentrate the ds cDNA instead of the usual ethanol precipitation. This resulted in almost 100% recovery of synthesized products at each step of this procedure.
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PMID:High-efficiency cloning of DNA sequences complementary to mouse neuroblastoma polyadenylated RNA. 286 33

The wild-type mouse hypoxanthine phosphoribosyltransferase (HPRT; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) gene has been isolated from genomic libraries and its structure has been determined. This X chromosome-linked gene is greater than 33 kilobases long and is split into nine exons. All the exon sequences have been determined, and a single-base substitution in the HPRT cDNA coding sequence from a mouse neuroblastoma cell line that overproduces a mutant HPRT protein has been identified. The 5' end of the gene has been defined, both by nuclease S1 protection and primer extension studies and by a functional assay in which an HPRT minigene, capable of expression in cultured cells, was created by ligating the 5' end of the gene onto wild-type human HPRT cDNA. Sequences normally associated with eukaryotic promoters are not present in the immediate 5'-flanking region of the HPRT gene, which is instead highly G+C rich. This observation is discussed in relation to the possible link between DNA methylation and X-chromosome inactivation.
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PMID:Structure, expression, and mutation of the hypoxanthine phosphoribosyltransferase gene. 632 7

Expression of the protein kinase C substrate MARCKS and other heat-stable myristoylated proteins have been studied in four cultured neural cell lines. Amounts of MARCKS protein, measured by [3H]myristate labeling and western blotting, were severalfold higher in rat C6 glioma and human HTB-11 (SK-N-SH) neuroblastoma cells than in HTB-10 (SK-N-MC) or mouse N1E-115 neuroblastoma cells. Higher levels of MARCKS mRNA were also detected in the former cell lines by S1 nuclease protection assay. At least two additional 3H-myristoylated proteins of 50 and 40-45 kDa were observed in cell extracts heated to > 80 degrees C or treated with perchloric acid. The 50-kDa protein, which bound to calmodulin in the presence of Ca2+, was more prominent in cells (N1E-115 and HTB-10) with less MARCKS, whereas neuromodulin (GAP-43) was detected in N1E-115 and HTB-11 cells only. Heating resulted in a fourfold increase in the detection of MARCKS by western blotting; this was not paralleled by a similar increase in [3H]myristate-labeled MARCKS and may be due to a conformational change affecting the C-terminal epitope or enhanced rechange of the protein on nitrocellulose. Addition of beta-12-O-tetradecanoylphorbol 13-acetate resulted in three- to fourfold increased phosphorylation of MARCKS in HTB-11 cells, with little increase noted in HTB-10 cells. These results indicate that MARCKS, neuromodulin, and other calmodulin-binding protein kinase C substrates exhibit distinct levels of expression in cultured neurotumor cell lines. Of these proteins, only MARCKS appears to be correlated with phorbol ester stimulation of phosphatidylcholine turnover in these cells.
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PMID:Differential expression of MARCKS and other calmodulin-binding protein kinase C substrates in cultured neuroblastoma and glioma cells. 796 53

Mouse Hoxb-4 (Hox-2.6) is a homeobox gene that belongs to a family which also includes Hoxa-4, Hoxc-4, and Hoxd-4 and that is related to the Deformed gene in Drosophila melanogaster. We have determined the sequence of 1.2 kb of 5' flanking DNA of mouse Hoxb-4 and by nuclease S1 and primer extension experiments identified two transcription start sites, P1 and P2, 285 and 207 nucleotides upstream of the ATG initiator codon, respectively. We have shown that this region harbors two independent promoters which drive CAT expression in several different cell lines with various efficiencies, suggesting that they are subject to cell-type-specific regulation. Through detailed mutational analysis, we have identified several cis-regulatory elements, located upstream and downstream of the transcription start sites. They include two cell-type-specific negative regulatory elements, which are more active in F9 embryonal carcinoma cells than in neuroblastoma cells (regions a and d at -226 to -186 and +169 to +205, respectively). An additional negative regulatory element has been delimited (region b between +22 and +113). Positive regulation is achieved by binding of HoxTF, a previously unknown factor, to the sequence GCCATTGG (+148 to +155) that is essential for efficient Hoxb-4 expression. We have also defined the minimal promoter sequences and found that they include two 12-bp initiator elements centered around each transcription start site. The complex architecture of the Hoxb-4 promoter provides the framework for fine-tuned transcriptional regulation during embryonic development.
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PMID:Multiple positive and negative regulatory elements in the promoter of the mouse homeobox gene Hoxb-4. 796 51

Neuroblastoma, the most common malignant solid cancer of children, has an ability to differentiate in vitro and in vivo. This biological property has a significant influence upon the prognosis of patients with neuroblastomas. Neuronal cells express three alternatively spliced forms of c-src mRNA (nonneuronal c-src, neuronal c-srcN1, and neuronal c-srcN2), which are found at different levels in adult and fetal human brain tissue. In this study, the transcriptional levels of the three c-src mRNAs were examined in relation to the neural differentiation in eight human neuroblastoma cell lines and two clonal sublines and in seven primary neuroblastoma tissues by S1 nuclease protection assays. Neuronal c-srcN1 mRNA was expressed at high levels in neuroblastoma cell lines with the ability to differentiate but not in the cell lines lacking the capacity to mature in response to chemical inducers irrespective of N-myc gene amplification and overexpression. In terminally differentiated neuroblastoma cells, the expression of neuronal c-srcN2 mRNA, which was barely detectable at a steady-state level in the uninduced cells, increased to significant levels. Infantile neuroblastomas identified by mass screening tests expressed both neuronal c-srcN1 and c-srcN2 mRNAs at levels almost identical to that found in human brain tissue, but terminally differentiated neuroblastoma cells, neuroblastomas from older children identified based on clinical symptoms, did not. These results suggest that neuronal c-src expression and the ability of neuroblastomas to differentiate in vitro and in vivo may be correlated.
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PMID:Expression of alternatively spliced src messenger RNAs related to neuronal differentiation in human neuroblastomas. 831 27

Cholinergic muscarinic receptor genes are members of the G-protein receptor gene superfamily. In this study we describe the structure of the gene and promoter of the rat m4 muscarinic receptor gene. A rat cosmid clone containing the coding region for the m4 gene and 25 kilobases of upstream sequence was isolated. This clone directed expression of the rat m4 gene when introduced in IMR32 cells, a human neuroblastoma that expresses m4, but did not drive expression when introduced into Chinese hamster ovary cells, a line that does not express the m4 gene. S1 nuclease, modified 5'-rapid amplification of cDNA ends and polymerase chain reaction analysis of rat cosmid DNA and cDNA showed that the gene consists of a 2.6-kilobase coding exon, extending 34 base pairs (bp) upstream from the initiating ATG, separated from a 460-493 bp noncoding exon by a 4.8-kilobase intron. DNA sequence analysis shows that the non-coding exon is GC-rich and that the promoter does not contain a TATA or CAAT box and has several consensus sequences for enhancer elements including five Sp-1 binding sites, one AP-2 site, one AP-3 binding site and two E-boxes within the proximal 600 bp. A reporter construct consisting of 1440 bp of flanking DNA and 80 bp of the first exon cloned into a luciferase reporter plasmid, drove cell specific expression in transient transfection assays. Removal of 1088 bp of the 5' end of this construct resulted in expression in non-m4 expressing cell lines suggesting there is a repressor element in this region.
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PMID:Structure of the m4 cholinergic muscarinic receptor gene and its promoter. 853 49

The mouse Sia alpha 2,3Gal beta 1, 4GalNAc alpha 2,8-sialyltransferase (ST8Sia III) genomic gene, whose transcripts are only expressed in fetal and newborn brain and testis, was isolated and its 5'-flanking region was analyzed. The gene was found to span about 8 kb and to be composed of only four exons. The genomic ST8Sia III gene is much smaller and its organization much simpler than other sialyltransferase genes so far reported, which span more than 25 kb and comprise seven or more exons. In particular, the sialyl motif L of ST8Sia III, which is a highly conserved region in all cloned sialyltransferases, was in one exon. In contrast, this motif is encoded by discrete exons in the other sialyltransferases. The ST8Sia III gene was highly expressed in the mouse brain and gave rise to at least three transcripts (2.1 kb, 2.4 kb, and 6.5 kb), which differed in the length of their 3'-untranslated regions through the alternative use of different polyadenylation sites. Primer extension and S1 nuclease protection analyses of mRNA prepared from newborn brain revealed that ST8Sia III gene expression started from a unique site at 382 nt upstream of ATG. Although the promoter region lacked an apparent TATA or CCAAT box and potential regulatory motifs, a transfection experiment involving neuroblastoma cells expressing ST8Sia III demonstrated the minimal promoter activity exhibited by the proximal region 418 bp upstream from the ATG codon, which suggests the presence of tissue-specific enhancer elements.
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PMID:Unique genomic structure and expression of the mouse alpha 2,8-sialyltransferase (ST8Sia III) gene. 892 52


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