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)

A 43-year-old white woman had a pheochromocytoma removed from her left adrenal gland, and one year later she developed a new left upper abdominal mass that was found to be a neuroblastoma. On both occasions, urinary vanillylmandelic acid level was elevated. However, urinary norepinephrine and epinephrine levels were increased only during the pheochromocytoma episode, while the urinary homovanillic acid level was elevated only when neuroblastoma developed. Despite a high suspicion of pheochromocytoma recurrence, the urinary catecholamine profile was suggestive of neuroblastoma, which was revealed by histopathologic analysis of the tumor tissue.
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PMID:Disparate urinary catecholamine patterns in secondary hypertension due to unique sequential development of pheochromocytoma and neuroblastoma. 274 60

A trophic factor secreted by PC12 rat pheochromocytoma augments growth of C1300 neuroblastoma clonal lines S20, N18 and C46, but does not affect growth of the NIE 115 line. A trophic factor present in newborn sympathetic ganglia has the same biological effect on neuroblastoma cell lines. PC12 cells and sympathetic ganglia are both of neural crest origin; possibly both secrete the same trophic factor.
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PMID:PC12 pheochromocytoma and sympathetic nervous system derived trophic factors augment growth of neuroblastoma. 275 61

We have found that neuroendocrine tumors (including neuroblastoma, ganglioneuroma, gut carcinoid, pheochromocytoma, medullary thyroid carcinoma, insulinoma, glucagonoma, prolactinoma, carotid body tumor, and small cell lung carcinoma) produce considerable amounts (about 1000-80,000 ng/g tissue) of the alpha subunit of guanine nucleotide-binding protein, GO (GO alpha), whereas nonneuroendocrine tumors contain less than 300 ng of GO alpha/g tissue. GO alpha in the neuroendocrine tumors was present both in the soluble fraction, and cholate-extractable membrane-bound fraction of tissues. Immunoblots of membrane fractions of neuroblastoma and carcinoid tissues confirmed that the immunoreactive substance in the tumor tissues was GO alpha. Immunohistochemically, GO alpha was localized consistently in the cell membrane and occasionally in the cytoplasm of neuroendocrine tumors. GO alpha was also detected in sera of 73% patients with neuroblastoma at diagnosis, whereas serum GO alpha concentrations in control children, or patients with nonneuroendocrine tumors were lower than the detection limit of the immunoassay method employed. Serum GO alpha concentrations in patients with neuroblastoma changed with the clinical course; they fell in patients responding to treatment and increased in patients who relapsed. Since GO alpha, a specific protein in the neural and neuroendocrine cells, was found to be produced in considerable amounts by all types of neuroendocrine tumors but not in nonneuroendocrine tumors, GO alpha might be a useful biomarker for neuroendocrine tumors.
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PMID:Production of the alpha subunit of guanine nucleotide-binding protein GO by neuroendocrine tumors. 282 34

Rat brain neuropeptide Y precursor (prepro-NPY) cDNA clones were isolated and sequenced in order to study regulation of the prepro-NPY gene. Rat prepro-NPY (98 amino acid residues) contains a 36-residue NPY sequence, followed by a proteolysis/amidation site Gly-Lys-Arg, followed by a 30-residue COOH-terminal sequence. The strong evolutionary conservation of rat and human sequences of NPY (100%) and COOH-terminal peptide (93%) suggests that both peptides have important biological functions. In the rat central nervous system, prepro-NPY mRNA (800 bases) is most abundant in the striatum and cortex and moderately abundant in the hippocampus, hypothalamus, and spinal cord. The rat adrenal, spleen, heart, and lung have significant levels of prepro-NPY mRNA. Regulation of the prepro-NPY mRNA abundance was studied in several rodent neural cell lines. PC12 rat pheochromocytoma and N18TG-2 mouse neuroblastoma cells possess low basal levels of prepro-NPY mRNA, while NG108-15 hybrid cells possess high levels. Treatment of PC12 cells with a glucocorticoid such as dexamethasone or elevation of cAMP by forskolin increased the prepro-NPY mRNA level 2-3-fold or 3-10-fold, respectively. In N18TG-2 cells dexamethasone and forskolin synergistically increased prepro-NPY mRNA 7-fold. Treatment of PC12 cells with the protein kinase C activator phorbol 12-myristate 13-acetate alone elevated prepro-NPY mRNA marginally, but the phorbol ester plus forskolin elicited 20-70-fold increases, which were further enhanced to over 200-fold by dexamethasone and the calcium ionophore A23187. These results indicate that NPY gene expression can be positively regulated by synergistic actions of glucocorticoids, cAMP elevation, and protein kinase C activation.
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PMID:Rat neuropeptide Y precursor gene expression. mRNA structure, tissue distribution, and regulation by glucocorticoids, cyclic AMP, and phorbol ester. 283 71

Two clonal cell lines (the pheochromocytoma clone PC-12 and the neuroblastoma clone N1E-115) were used to compare direct and indirect drug effects on tyrosine hydroxylase and dopamine turnover. Both clones contain the cofactor of tyrosine hydroxylase, tetrahydrobiopterin, in sufficient concentrations. 2,4-Diamino-6-hydroxy-pyrimidine (DAO-Pyr), an inhibitor of GTP cyclohydrolase, which is the rate-limiting enzyme in tetrahydrobiopterin biosynthesis, lowers DOPA production indicating that cofactor supply is a limiting factor for catecholamine synthesis. DOPA synthesis in the PC-12 cells can be stimulated by incubation with the natural cofactor tetrahydrobiopterin, but also by its possible precursors sepiapterin and dihydrobiopterin or the analogs methyl-tetrahydropterin and dihydropterin. The regulating enzyme for DOPA synthesis, tyrosine hydroxylase, can be inhibited by certain drugs either directly or indirectly by increasing dopamine concentrations in the cytoplasm after release from its vesicular stores. Using the neuroblastoma clone N1E-115 which lacks DOPA decarboxylase and thus contains only low levels of dopamine the site of action of certain drugs could be determined. Drugs affecting the tyrosine hydroxylase directly (alpha-methyl-para-tyrosine, apomorphine) decreased DOPA production in both clones, while drugs acting via interference with the vesicular stores (reserpine, amphetamine, nigericin) were effective only in the PC-12 cells. After total depletion of dopamine by nigericin at high concentrations or long-term incubation with 3-hydroxybenzyl-hydrazine (NSD 1015), DOPA production increased in the PC-12 cells indicating a usually occurring regulation of tyrosine hydroxylase by cytoplasmic dopamine. Dopamine concentration in the cytoplasm was calculated to be in the range of 1 X 10(-6) mol/l.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evaluation of neurotropic drug actions on tyrosine hydroxylase activity and dopamine metabolism in clonal cell lines. 285 29

While 131I-meta-iodobenzyl guanidine (131I-MIBG) scanning has made possible the scintigraphic visualization of pheochromocytoma and neuroblastoma, an accumulation of this agent has recently been reported in medullary thyroid cancer. We present the case of a patient with Sipple's syndrome (multiple endocrine neoplasia type IIa), in whom we were able to identify distant metastases and local invasion of medullary thyroid cancer as well as primary thyroid tumour and right adrenal pheochromocytoma, using 131I-MIBG scans. This case highlights the usefulness of 131I-MIBG in the detection of metastatic medullary thyroid cancer and suggests that this agent may also be of therapeutic use in the treatment of tumours.
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PMID:Detection of metastatic medullary thyroid cancer with 131I-MIBG scans in Sipple's syndrome. 287 28

131I-meta-iodobenzylguanidine (131I-MIBG) was also taken up by medullary thyroid carcinoma (MTC) as well as by pheochromocytoma in two patients with Sipple's syndrome. However, the mechanism of 131I-MIBG uptake by MTC has not been clarified yet. We measured tissue catecholamine levels in three MTC, since MTC can produce several active substances. Catecholamines were detected in various amounts in all MTC, but not in normal thyroid tissues. These findings suggest that MTC can produce catecholamines and therefore, 131I-MIBG is taken up and stored in catecholamine vesicles of MTC, like pheochromocytoma and neuroblastoma. We conclude that 131I-MIBG may be applied not only to diagnosis but also for the treatment of patients with MTC.
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PMID:Imaging and uptake mechanism of 131I-meta-iodobenzylguanidine in medullary thyroid carcinoma. 287 69

Tyrosine hydroxylase and tryptophan hydroxylase are widely held to be rate-limiting for the synthesis of the catecholamines and serotonin, respectively. Both enzymes are oxygen-requiring and kinetic properties suggest that oxygen availability may limit synthesis of these neurotransmitters in the brain. Using pheochromocytoma cells as a cell culture model for catecholamine synthesis, and neuroblastoma cells as a model for serotonin synthesis, enzyme activity was measured under control and hypoxic conditions. Both tyrosine hydroxylase and tryptophan hydroxylase activity increased substantially with chronic exposure but not with acute exposure. In the case of tyrosine hydroxylase, increased enzyme content with hypoxia accounts for increased activity. This suggests a mechanism for the maintenance of neurotransmitter synthesis with chronic hypoxia. Measurement of intracellular metabolites revealed no change in dopamine or norepinephrine in hypoxic pheochromocytoma cells, consistent with a simple adaptive mechanism. However, in neuroblastoma cells, hypoxia was associated with an increase in serotonin concentration. The reasons for this are still unclear.
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PMID:Adaptations of neurotransmitter synthesis to chronic hypoxia in cell culture. 288 82

We report a retrospective study of two years experience with I-131-metaiodobenzylguanidine (MIBG). I-131 MIBG was prepared locally and was found to have decreased background activity as compared with other available commercial preparations from Great Britain and the United States. Fifty-nine patients were studied with a total of 65 scans. The study included 11 members of a family with multiple endocrine adenomatosis (MEA) type II syndrome. Of 16 patients found to have abnormal scans, 12 had disease confirmed surgically. These cases consisted of nine pheochromocytomas, one paraganglioma, one neurilemmoma, and one neuroblastoma. MIBG scans for pheochromocytoma detection had an accuracy of 94.5%, a sensitivity of 100%, and a specificity of 93.5% in this study of patients with a high prior probability of the disease.
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PMID:Experience with I-131-metaiodobenzylguanidine (MIBG): a retrospective study. 288 22

The authors describe their experiences with 100 MIBG scintigraphies. The importance of the examination is stressed in the diagnostics of neuroblastoma in childhood, the determination of the clinical stage and follow-up of the disease. MIBG scintigraphy plays a primary role among the imaging examination procedures aimed at the localization of pheochromocytoma especially in the extra-adrenal, multiplex and malignant diseases. The disturbance of adrenergic innervation in Shy-Drager syndrome is demonstrable with radiopharmacon.
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PMID:[Scintigraphy of the adrenergic nervous system]. 291 85


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