Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Catecholamine storage was examined in cultures of the murine neuroblastoma cell line, N-TD6, using histofluorescence, electron microscopic, isotopic and radioautographic criteria. This line was originally derived from uncloned, C1300 tumor cells by selection in tyrosine deficient medium. N-TD6 cells possess both tyrosine hydroxylase (tyrosine-3-monooxygenase, EC 1.14.16.2) and dopamine beta-hydroxylase (dopamine beta-monooxygenase, EC 1.14.17.1) activities. When examined for paraformaldehyde-induced histofluorescence, a small percentage of cells in the population show intense catecholamine fluorescence, often localized within discrete regions of the cellular processes. Electron microscopic examination of these cells reveals both electron lucent vesicles and more frequent, electron dense granules, 50-70 nm and 100-300 nm in diameter, respectively. The distribution of these granules and vesicles varies, but they appear most numerous near the cell surface, along processes and within process endings. By labeling cells with [3H]dopamine and then allowing the cells to release unbound label in the presence of unlabeled dopamine, the localization of catecholamine stores was visualized by radioautographic techniques. While a variety of intracellular distribution of radioactivity were observed, the most prominent concentrations were found in the processes and their terminals; no labeled material was retained when reserpine was present during uptake. The topographic coincidence of granules, catecholamine fluorescence and [3H]dopamine retention in these neuroblastoma cells suggests that catecholamines are stored within these granules in a manner analogous to that observed in normal adrenergic neurons.
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PMID:Localized catecholamine storage associated with granules in murine neuroblastoma cells. 24 Apr 85

Initial urinary catecholamine metabolite and amino acid excretion patterns were examined in 54 children with neuroblastoma. The relationships between prognosis and age at diagnosis, stage of disease, primary site, and histologic grade of tumor were similar in this population to those found in previous studies, but only age and stage were found to be independent prognostic variables. Prognosis in disseminated disease was found to correlate directly with the urinary vanilmandelic acid (VMA)/homovanillic acid (HVA) ratio but not with the absolute levels of HVA. The presence of the dopa metabolite, vanillactic acid, as well as increased amounts of cystathionine and/or low levels of VMA indicated poor prognosis. These results are consistent with the hypothesis that biochemically primitive neuroblastomas deficient in dopamine beta-hydroxylase are move virulent than their mature analogues which produce epinephrine, norepinephrine, and their metabolites.
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PMID:Initial urinary catecholamine metabolite concentrations and prognosis in neuroblastoma. 68 87

Dopamine beta-hydroxylase, the enzyme which converts dopamine to norepinephrine, is expressed in a cell type-restricted pattern in neuroendocrine tissue. A segment of the rat gene containing 395 bases of 5'-flanking sequence regulates expression of a reporter gene in a cell type-selective pattern in mammalian cell cultures. Using deletion mutants of the 5'-flanking sequence, we have identified a 30-base genetic regulatory element, designated DB1, which enhances transcription from a heterologous promoter 5-20-fold in neuroendocrine cell lines. DB1-specific DNA-protein complexes are found in nuclear extracts from all cell lines examined, but the migration pattern differs between cell lines. The 5'-flanking region of the dopamine beta-hydroxylase gene is also responsive to cyclic AMP and phorbol ester treatment of SHSY-5Y neuroblastoma cells. The simultaneous presence of both effectors results in synergistic increases in DBH1 mRNA and reporter gene activity. The second messenger regulatory element was localized to the region containing the DB1 element, and reporter plasmids containing multiple copies of the DB1 element are responsive to treatment with inducers. The results of this study identify a cis-acting regulatory element which influences both cell type selectivity and second messenger responsiveness of the rat dopamine beta-hydroxylase gene.
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PMID:A bifunctional genetic regulatory element of the rat dopamine beta-hydroxylase gene influences cell type specificity and second messenger-mediated transcription. 138 62

Dopamine beta-hydroxylase exists as three forms in human neuroblastoma (SH-SY5Y) cells. The membrane-bound form of the hydroxylase contains three different species with apparent relative molecular weights of 73,000, 77,000, and 82,000. The intracellular soluble form of dopamine beta-hydroxylase was present as a single species with an apparent molecular weight of 73,000. Pulse-chase experiments showed that membranous dopamine beta-hydroxylase contains two subunit forms of 73,000 and 77,000 after short chase times. The soluble hydroxylase was synthesized as a single species of 73,000 at approximately the same rate as the lower molecular weight species of the membranous enzyme. A constitutively secreted third form of the enzyme with an intermediate apparent molecular weight also incorporated [35S]sulfate, whereas no significant amount of [35S]sulfate was observed in the cellular forms of the enzyme. The [35S]sulfate was incorporated on N-linked oligosaccharides. Approximately 12% of the enzyme is released constitutively within 1 h. These results demonstrate that neuronal cells have the ability to constitutively secrete a specific form of dopamine beta-hydroxylase which may contribute to the levels of this enzyme found in plasma.
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PMID:Multiple forms of human dopamine beta-hydroxylase in SH-SY5Y neuroblastoma cells. 192 17

Neuroblastomas are malignant childhood neoplasms that arise from derivatives of the neural crest. We report the characterization of a new neuroblastoma cell line, designated NBL-W, derived from the primary tumor of a patient with stage IVS disease (S. L. Cohn, C. V. Herst, H. S. Maurer, and S. T. Rosen, J. Clin. Oncol., 5: 1441-1444, 1987) according to the criteria of Evans [A. E. Evans, G. J. D'Angio, and J. Randolf, Cancer (Phila.), 27: 374-378, 1971]. Neurite-bearing (N) and substrate-adherent (S) cell lines have been subcloned from the parent line. N and S cells can interconvert, and both cell types label with the neural crest cell surface marker antibody, HNK-1. Cells in the subcloned lines and in the parent line have been shown by Southern blot analysis to contain approximately 100 copies of the N-myc gene. Cytogenetic analysis shows a homogeneously staining region present on chromosome 19. Although these subclones are of identical genotype, the S cells express lower amounts of N-myc mRNA and protein as compared to the N cells. N cells express several neuronal proteins including the neurotransmitter-processing enzymes tyrosine hydroxylase and dopamine beta-hydroxylase, the neuronal intermediate filament proteins peripherin and NF66/alpha-internexin, and the neural cell adhesion molecule. S cells generally lack neuronal markers but express the mesenchymal intermediate filament protein vimentin, and a small subset of the S cells express glial fibrillary acidic protein. Some S cells were labeled weakly with neural cell adhesion molecule antibody; others were negative. S cells did not express the glial marker S-100 or a melanocyte marker, tyrosinase. Thus, S cells express the neural crest marker HNK-1 but do not express a set of antigens characteristic of any known cell type derived from the neural crest. These results are consistent with the suggestion that differential N-myc expression may be involved in the interconversion of N and S cells but indicate that the S cell phenotype need not represent a highly differentiated neural crest derivative.
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PMID:Differential expression of N-myc in phenotypically distinct subclones of a human neuroblastoma cell line. 193 96

As neuroblastoma, the most common solid tumour in childhood, may contain all the constituents of the catecholamine biosynthesis cascade, some of these constituents may be produced in excess in a varying mixture reflecting the wide variability in expression of differentiated features of the tumour. We have measured plasma levels of norepinephrine (NE), epinephrine (E), dopamine (DA) and 3,4-dihydroxyphenylalanine (DOPA), and plasma activities of dopamine beta-hydroxylase (DBH) and aromatic L-amino acid decarboxylase (ALAAD) in 18 patients with neuroblastoma, in 13 at various times during the course of their disease. Activities of serum lactic dehydrogenase (LDH), serum levels of ferritin (FER) and neuron-specific enolase (NSE), and urinary vanilmandelic acid (VMA) were also determined. NE, E and DBH were found not to reflect tumour activity. In untreated active neuroblastoma DOPA or ALAAD (10 out of 10) or both (six out of 10) were clearly elevated. In all 13 patients where samples were obtained during chemotherapy, ALAAD activities fell within the normal range, while DOPA decreased more slowly. During relapse, DOPA and, especially, ALAAD, rapidly increased; in all six patients who had a relapse both DOPA and ALAAD were elevated. In complete remission (eight patients), ALAAD was normal in all patients, but DOPA remained elevated in the one patient who later experienced a relapse. Our preliminary conclusion is that combined measurements of plasma ALAAD and DOPA may be useful markers for neuroblastoma activity at diagnosis, but even more so in indicating residual disease (DOPA) and in the early detection of relapse (ALAAD).
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PMID:Combined measurements of plasma aromatic L-amino acid decarboxylase and DOPA as tumour markers in diagnosis and follow-up of neuroblastoma. 250 83

Previous studies have shown that catecholamine secretion patterns have been imperfect predictors of clinical behavior of neuroblastomas. Recently, studies of nuclear DNA content in neuroblastoma have shown that an aneuploid DNA content predicts favorable clinical behavior. To determine if a correlation exists between these tumor biologic indicators, the authors analyzed both in a series of 39 patients with neuroblastoma. Flow cytometric DNA analysis performed on paraffin blocks determined that 23 patients had tumors with aneuploid DNA content (aneuploid tumors) and 16 patients showed no demonstrable anomalies of tumor DNA content (nonaneuploid tumors). Comparison of catecholamine levels in urine and tumor homogenates with DNA content data indicate that nonaneuploid neuroblastomas include a significant number (P less than 0.02) of biochemically primitive tumors which secrete high levels of 3,4 dihydroxyphenylalanine (DOPA), dopamine and homovanillic acid (HVA). This suggests a dopamine-norepinephrine pathway block, which supports previous reports of deficiency of dopamine beta-hydroxylase activity in some neuroblastomas. The study shows that in contrast to aneuploid tumors, nonaneuploid neuroblastomas secrete higher levels of early pathway catecholamine metabolites and are more likely to present in higher (unfavorable) clinical stages of disease.
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PMID:Flow cytometry DNA ploidy analysis and catecholamine secretion profiles in neuroblastoma. 270 81

Fusaric acid, an inhibitor of dopamine beta-hydroxylase, which converts dopamine to noradrenaline, lowered the blood pressure and induced a subjective improvement in patients with phaeochromocytoma. These effects may be due either to an impairment of catecholamine biosynthesis or to a direct action on the blood vessels. The use of this drug in the treatment of patients with inoperable malignant phaeochromocytoma or neuroblastoma may improve symptoms and prolong survival.
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PMID:Effect of fusaric acid (a dopamine beta-hydroxylase inhibitor) on phaeochromocytoma. 398 67

The distribution of the enzymatic activity of dopamine beta-hydroxylase (DBH) in linear sucrose gradients was studied for a soluble fraction of the C1300 mouse neuroblastoma tumor, for the serum of tumor-bearing A/J mice, and for adrenal tissue and serum of control mice. In controls (adrenal gland and serum of A/J mice), about 75% of the DBH activity was associated with a high-molecular-weight form, denoted as DBHA, with an apparent sedimentation coefficient of 11.3 S. About 25% of the DBH activity was attributable to a slower-sedimenting species (7.1 S), denoted as DBHB. In tumor supernatants and in the serum of tumor-bearing mice, about 55% of the DBH activity was present as the 7.1 S species (DBHB), while only 35% was recovered as the high-molecular-weight form (DBHA). Approximately 5% of the activity could be attributed to a separate form, with a sedimentation coefficient of about 4.5 S. This form is designated DBHC. The ratio DBHB/DBHA is significantly higher in tumor tissue and in serum of tumor-bearing mice than in controls. The three enzymically active forms of DBH in the C1300 tumor are considered to represent the tetrameric (DBHA), dimeric (DBHB), and monomeric (DBHC) forms of the enzyme.
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PMID:Multiple molecular forms of dopamine beta-hydroxylase in the C1300 mouse neuroblastoma tumor and in the serum of tumor-bearing mice. 711 88

Expression of the gene encoding the neurotransmitter biosynthetic enzyme dopamine beta-hydroxylase (DBH) is regulated in a tissue-specific pattern, and transcription is influenced by environmental stimuli. Using the promoter proximal region of the rat DBH gene and nuclear extracts from SHSY-5Y neuroblastoma cells, a DNA-protein complex was identified that is competitive with oligonucleotides containing the recognition site of transcription factor AP-2. DNase footprint analysis identified an AP-2 binding site between -136 and -115 of the DBH promoter. Mutation of that AP-2 site results in a sevenfold reduction of basal reporter gene expression, but second messenger-stimulated activity is retained. Cotransfection of an AP-2 expression vector and a DBH promoter-reporter construct into cultured cells results in a sixfold stimulation of reporter gene expression, demonstrating the ability of AP-2 to trans-activate the DBH promoter. These results identify a new regulatory element on the rat DBH gene and suggest that the AP-2 site plays a role in maintaining basal levels of DBH transcription.
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PMID:Transcription factor AP-2 regulates expression of the dopamine beta-hydroxylase gene. 761 4


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