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)

Treatment of neuroblastoma cells with dibutyryl-adenosine 3':5'-monophosphate or adenine induced axon formation and a three-fold increase in the polyadenylate, poly(A), content of the polysomal mRNA. The extracted poly(A) contained 90% adenylic acid and showed a mobility of 6--7 S in dodecylsulfate-polyacrylamide gel electrophoresis. Treatment with dibutyryl-adenosine 3':5'-monophosphate or adenine, also induced a 4--6 fold increase in a nuclear enzymic activity that incorporated [3H]ATP to an acid-insoluble polymer in a cell-free system. This polymer, like poly(A) extracted from the polysomal mRNA, was bound at high salt concentration to nitrocellulose filters. [3H]ATP incorporation was Mg2+-dependent, sensitive to ribonuclease and EDTA and resistant to deoxyribonuclease and actinomycin D. There was no incorporation of [3H]UTP or [3H]dTTP and addition of TUP, CTP and GTP did not increase the incorporation of [3H]ATP. 5-Bromodeoxyuridine induced axon formation of neuroblastoma cells and poly(A) polymerase activity, without increasing the poly(A) content in the polysomal mRNA. The results indicate that induction of axon formation of neuroblastoma cells is associated with an increase in the activity of poly(A) polymerase. It is suggested that the induction of this enzyme may be generally involved in cell differentiation.
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PMID:Induction of polyadenylate polymerase and differentiation in neuroblastoma cells. 17 99

Northern blot and ribonuclease protection assay were used to identify alpha 2-adrenoceptor subtypes in human colonic adenocarcinoma (HT29), neuroblastoma x glioma rat-mouse hybrid NG108-15 (NG108) and opossum kidney (OK) cell lines. Radioligand binding studies showed that the alpha 2-adrenoceptor expressed in HT29, NG108 and OK cells represent the pharmacological alpha 2A, alpha 2B and alpha 2C subtypes respectively. In our Northern blot analysis, hybridization of poly(A)+ RNA from HT29, NG108 and OK cells with human kidney alpha 2-adrenoceptor cDNA probe (alpha 2-C4) identified a single band of 4.4, 4.2 and 4.4 kb respectively in each cell line. Hybridization with a human platelet alpha 2-adrenoceptor genomic probe (alpha 2-C10) resulted in two bands for HT29 cells with the size of 4.4 kb and 3.9 kb. No bands were seen for HT29, NG108 and OK cells when hybridized with a third alpha 2-adrenoceptor human genomic DNA probe which is localized in chromosome 2 (alpha 2-C2). For the HT29 cells, the 3.9 kb band was seen only when using the alpha 2-C10 probe. Thus, this band probably represents alpha 2-C10 mRNA. To further characterize the alpha 2-adrenoceptor mRNA expressed in HT29, NG108 and OK cells, the sensitive ribonuclease protection assay was performed. A single band about 900 bp was protected when the poly(A)+ RNA from NG108 and OK cells was hybridized with an alpha 2-C4 RNA probe and digested with RNAases. Hybridization of mRNA from HT29 cells with alpha 2-C10 RNA probe and digestion with RNAases protected a 500 bp fragment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Northern blot and ribonuclease protection study of alpha 2-adrenoceptor subtypes in cultured cell lines. 132 48

Drug resistance is one of the major impediments to the treatment of advanced neuroblastoma. Two neuroblastoma cell lines established from the same patient before (KP-N-AY) and after (KP-N-AYR) chemotherapy are described. Both cell lines were established from bone-marrow metastases of a 2 1/2-year-old patient with stage IV neuroblastoma. Chromosomal analysis, catecholamine assessment and the surface membrane phenotype of these cell lines confirmed that the tumors were of neuroblastoma origin. Compared with the KP-N-AY cell line, the KP-N-AYR line had decreased N-myc amplification but increased N-myc expression. An in vitro sensitivity test using a clonogenic assay showed the KP-N-AYR cell line to be 3.0-fold resistant to adriamycin and 2.7-fold resistant to cis-platinum as compared with the KP-N-AY cell line. The expression of the multi-drug-resistance gene (MDR1) was not observed in either cell line by the ribonuclease protection assay. The KP-N-AY cell line revealed only faint MDR1 RNA by the polymerase chain reaction, whereas the KP-N-AYR cell line had no expression of the MDR1 gene. The level of glutathione-S-transferase-pi was significantly higher in the KP-N-AYR cell line than in the KP-N-AY cell line. These findings suggest that the development of clinical drug resistance may be associated with the enhanced glutathione-S-transferase-pi activity but not with MDR1 gene expression.
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PMID:Different drug sensitivity in two neuroblastoma cell lines established from the same patient before and after chemotherapy. 200 54

Tryptophan residues in ribonuclease from a Rhizopus sp. (RNase Rh) were modified by NBS, H2O2-dioxane, o-nitrophenylsulfenyl chloride (NPS-Cl) and the relation between the extent of modification and enzymatic activity was studied in each case. By extrapolation of the modified tryptophan residue-enzymatic activity curve to a completely inactive state, it was found that modification of 1-2 tryptophan residues is responsible for loss of enzymatic activity. RNase Rh was partly protected from modification by H2O2-dioxane (pH 8.4) and NPS-Cl (pH 3.5) when in the presence of 2'-AMP and the fluorescence emission spectrum of RNase Rh was quenched by adding 2'-AMP. It seems, therefore, that 1 or 2 tryptophan residues are involved in the active site of RNase Rh or are located near the active site. The solvent perturbation difference spectra of RNase Rh were measured using ethylene glycol and D2O as perturbants. The results indicated that 1.2 tryptophan residues for D2O and 1.9 tryptophan residues for ethylene glycol were exposed to the solvents. These data show that about 1.2-1.9 tryptophan residues are exposed to the solvent and their modification causes loss in enzymatic activity.
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PMID:Chemical modification of tryptophan residues in ribonuclease from a Rhizopus sp. 739 Sep 80

While interleukin-2 (IL-2) has been shown to produce a variety of effects in the CNS and has recently been implicated as an endogenous brain neurokine, little is known about the molecular biology of IL-2 receptors in normal brain. The present investigation provides the first evidence that mRNA for IL-2 receptor-beta (IL-2R beta), an essential subunit for signal transduction by peripheral immune cells, is expressed in normal murine forebrain. Using polymerase chain reaction (PCR) cloning, a partial cDNA (349 bp) corresponding to the extracellular domain was cloned and found to have the identical sequence as the lymphocyte IL-2R beta. IL-2R beta mRNA expression was confirmed by a ribonuclease protection assay, and using in situ hybridization histochemistry, IL-2R beta mRNA was localized in the hippocampus where an intense signal was present over the neuron-rich granule cells of the dentate gyrus and Ammon's horn. Moreover, cDNA clones obtained from two murine neuroblastoma cell lines exhibited the same sequence as IL-2R beta cDNA from normal brain. IL-2R beta gene expression was also detected in the frontal cortex and striatum using PCR. Further in situ hybridization studies will be important to extend this initial observation to determine the brain regional localization and cell-specific anatomy of IL-2R beta mRNA in the CNS.
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PMID:Molecular cloning of a partial cDNA of the interleukin-2 receptor-beta in normal mouse brain: in situ localization in the hippocampus and expression by neuroblastoma cells. 795 64

The beta1,4-N-acetylgalactosaminyltransferase (beta1,4GalNAc-T) (EC) gene is expressed in normal brain tissues and in various malignant transformed cells, such as malignant melanoma, neuroblastoma, and adult T cell leukemia. To analyze the regulatory mechanisms of gene expression, we determined the genomic organization of the beta1, 4GalNAc-T gene. The gene consists of at least 11 exons and spans >8 kilobase pairs. The coding region is located in exons 2-11. To determine the transcription initiation sites, 5'-rapid amplification of cDNA ends analysis and ribonuclease protection assays were performed using RNA obtained from the human melanoma cell line SK-MEL-31. Consequently, we defined three transcription initiation sites and the alternative usage of three exons. Exons 1a and 1b partially overlap; the latter is part (3'-side) of the former and corresponds to the 5'-noncoding region of the cDNA clone previously isolated. The third transcript, exon 1c, corresponds to nucleotides -520 to -412 (position +1 = A of ATG of beta1,4GalNAc-T cDNA), which are considered to be in intron 1 based on the cloned cDNA sequence. Ribonuclease protection assays revealed the corresponding protection bands in samples of the gene-expressing cell lines. 5'-Flanking regions of individual initiation sites showed promoter activity when analyzed by chloramphenicol acetyltransferase assay in SK-MEL-31 cells. The multiple transcription initiation sites and their promoters/enhancers identified here might be differentially involved in the cell type-specific expression of the beta1,4GalNAc-T gene. This gene was assigned to human chromosome 12q13.3 by means of fluorescence in situ hybridization.
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PMID:Genomic organization and chromosomal assignment of the human beta1, 4-N-acetylgalactosaminyltransferase gene. Identification of multiple transcription units. 870 39

The human D1A dopamine receptor gene has a GC-rich, TATA-less promoter located upstream of a small, noncoding exon 1, which is separated from the coding exon 2 by a 116-base pair (bp)-long intron. Serial 3'-deletions of the 5'-noncoding region of this gene, including the intron and 5'-end of exon 2, resulted in 80 and 40% decrease in transcriptional activity of the upstream promoter in two D1A-expressing neuroblastoma cell lines, SK-N-MC and NS20Y, respectively. To investigate the function of this region, the intron and 245 bp at the 5'-end of exon 2 were investigated. Transient expression analyses using various chloramphenicol acetyltransferase constructs showed that the transcriptional activity of the intron is higher than that of the upstream promoter by 12-fold in SK-N-MC cells and by 5.5-fold in NS20Y cells in an orientation-dependent manner, indicating that the D1A intron is a strong promoter. Primer extension and ribonuclease protection assays revealed that transcription driven by the intron promoter is initiated at the junction of intron and exon 2 and at a cluster of nucleotides located 50 bp downstream from this junction. The same transcription start sites are utilized by the chloramphenicol acetyltransferase constructs employed in transfections as well as by the D1A gene expressed within the human caudate. The relative abundance of D1A transcripts originating from the upstream promoter compared with those transcribed from the intron promoter is 1.5-2.9 times in SK-N-MC cells and 2 times in the human caudate. Transcript stability studies in SK-N-MC cells revealed that longer D1A mRNA molecules containing exon 1 are degraded 1.8 times faster than shorter transcripts lacking exon 1. Although gel mobility shift assay could not detect DNA-protein interaction at the D1A intron, competitive co-transfection using the intron as competitor confirmed the presence of trans-acting factors at the intron. These data taken together indicate that the human D1A gene has two functional TATA-less promoters, both in D1A expressing cultured neuroblastoma cells and in the human striatum.
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PMID:Two distinct promoters drive transcription of the human D1A dopamine receptor gene. 881 Feb 92

The presence of luteinizing hormone-releasing hormone (LHRH) in SK-N-SH human neuroblastoma cells was investigated by immunocytochemistry and enzyme-linked immunosorbent assays of whole cell extracts and culture medium. In addition, ribonuclease protection assays were utilized to quantitate LHRH messenger RNA. The expression of LHRH mRNA and LHRH protein level was correlated with neuronal differentiation induced by retinoic acid (RA). In differentiated SK-N-SH cells the LHRH mRNA level as well as the amount of LHRH in cell extracts and cell medium were significantly lower than in differentiated cells. These results suggest that RA affects the expression of LHRH mRNA and the level of LHRH protein in SK-N-SH cells. These data show that altering the growth state of the human neuroblastoma SK-N-SH cells toward more neuronal phenotype results in a significant decrease in expression of LHRH mRNA and the protein. The ability of RA to induce changes in LHRH at the mRNA and at the peptide levels will allow further study of RA regulation of LHRH at the neuronal level.
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PMID:Luteinizing hormone-releasing hormone in undifferentiated and differentiated SK-N-SH human neuroblastoma cells. 886 5

The adult ventricular isoform of chicken myosin heavy chain (MHC-V) is transiently expressed in all skeletal muscle primordia analyzed and is completely repressed around embryonic days 10-12, when functional innervation is established. By ribonuclease protection assay, we demonstrated that denervation of the adult anterior latissimus dorsi muscle resulted in reexpression of MHC-V mRNA. In contrast, treatment of primary cultures of fetal breast or leg muscles with embryonic brain extract or conditioned media from glial or neuroblastoma cell lines, but not from a myogenic cell line or primary muscle cell cultures, led to inhibition of MHC-V expression. This inhibitory activity was abolished by heating and increased with protein concentration. The acquisition of both brain inhibitory activity and the competence of myogenic cells to downregulate MHC-V mRNA expression were age dependent. Furthermore, either paralysis of muscle in ovo by curare or contraction arrest of cultured myotubes resulted in persistent expression of MHC-V mRNA. Thus a putative soluble factor(s) of nerve origin as well as muscle activity are involved in the developmental downregulation of MHC-V expression in muscle primordia.
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PMID:Developmental shift of myosin heavy chain mRNA expression due to neural factor(s) and muscle activity. 889 42

Onconase is a cytotoxic ribonuclease with antitumor properties. A semisynthetic gene encoding the entire protein sequence was constructed by fusing oligonucleotides coding for the first 15 and the last 6 of the 104 amino acids to a genomic clone that encoded the remaining amino acid residues [Newton, D. L., et al. (1997) Protein Eng. 10, 463-470]. The resulting protein product expressed in Escherichia coli exhibited little enzymatic or cytotoxic activity due to the unprocessed N-terminal Met amino acid residue. In this study, we demonstrate that modification of the 5'-region of the gene to encode [Met-(-1)]Ser or [Met-(-1)]Tyr instead of the native pyroglutamate results in recombinant onconase derivatives with restored activities. [Met-(-1)]rOnc(E1S) was more active than [Met-(-1)]rOnc(E1Y) in all assays tested. Consistent with the action of native onconase, [Met-(-1)]rOnc(E1S) was a potent inhibitor of protein synthesis in the cell-free rabbit reticulocyte lysate assay, degrading tRNA at concentrations that correlated with inhibition of protein synthesis. An interesting difference between the recombinant onconase derivatives and the native protein was their susceptibility to inhibition by the major intracellular RNase inhibitor, PRI (onconase is refractory to PRI inhibition). [Met-(-1)]rOnc(E1S) and [Met-(-1)]rOnc(E1Y) inhibited protein synthesis in intact SF539 neuroblastoma cells with IC50's very similar to that of onconase (IC50 3.5, 10, and 10 microg/mL after 1 day and 0.16, 0.35, and 2.5 microg/mL after 5 days for onconase, [Met-(-1)]rOnc(E1S), and [Met-(-1)]rOnc(E1Y), respectively). Similar to that of onconase, cytotoxic activity of the recombinant derivatives was potentiated by monensin, NH4Cl, and retinoic acid. Brefeldin A completely blocked the enhancement of cytotoxicity caused by retinoic acid with all three proteins. Thus, drug-induced alterations of the intracellular trafficking of the recombinant derivatives also resembles that of onconase. Stability studies as assessed in serum-containing medium in the presence or absence of cells at 37 degreesC showed that the recombinant proteins were as stable to temperature and cell culture conditions as the native protein. Therefore, exchanging the Glu amino acid residue at the amino terminus of onconase with an amino acid residue containing a hydroxyl group produces recombinant proteins with ribonuclease and cytotoxic properties similar to native onconase.
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PMID:Single amino acid substitutions at the N-terminus of a recombinant cytotoxic ribonuclease markedly influence biochemical and biological properties. 954 48


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