Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.14.16.2 (tyrosine hydroxylase)
 14,760 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the hypothesis that nonhematopoietic malignancies may contain cells corresponding to those which occur during the differentiation of tissue precursors. Neuroblastoma, an embryonal tumor of the adrenal medulla, was studied because of its well described ability to differentiate both in vivo and in vitro. We examined the expression of four genes during development of the human adrenal medulla: tyrosine hydroxylase, chromagranin A, pG2, and beta-2-microglobulin. The sequential expression of these genes by adrenal neuroblasts marks successive stages during maturation of the chromaffin lineage. We also observed a population of neuroblasts during adrenal medullary development that did not express any of these four genes, suggestive of adrenal medullary cells differentiating along nonchromaffin lineage(s). We then evaluated 27 neuroblastoma cell lines for the expression of these genes and found that 24 expressed chromaffin markers, with 19 of these mimicking the pattern of gene expression found during development. Three cell lines did not express tyrosine hydroxylase, chromogranin A, or pG2, consistent with either a very undifferentiated neural crest cell or maturation along a nonchromaffin lineage. These data indicate that neuroblastoma tumor cells correspond to adrenal neuroblasts arrested during morphogenesis of the adrenal medulla and raise the possibility that malignant transformation of cells at different stages of tissue maturation may contribute to the diversity that characterizes tumors of solid tissues.
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PMID:Human neuroblastoma tumor cell lines correspond to the arrested differentiation of chromaffin adrenal medullary neuroblasts. 198 60

The biochemical, pharmacological and immunological characterization of cells derived from human neuroblastoma tumors recently acquired great interest, since these cells may be a putative donor source for transplantation in animal models of neurological disorders. We measured monoamine levels, tyrosine hydroxylase (TH) immunostaining, and the expression of major histocompatibility cell surface antigens (MHC) in 7 human neuroblastoma cell lines. Three cell lines (LAN5, NB69 and CHP126) had high levels of monoamines. TH immunostaining was strongly positive in CHP126 and LAN5, and NB69. MHC were not detected in any of the cells with high catecholamine levels. Treatment with neuroleptics increased the metabolism of dopamine in LAN5 but not in NB69. The implantation of LAN5 cells in immunocompetent, unilaterally 6-hydroxydopamine-lesioned rats decreased the apomorphine-induced contralateral rotation. The effect of the implant was greatest in animals in which LAN5 neuroblastoma cells, pretreated with dibutyryl cyclic adenosine monophosphate (DBcAMP) and prostaglandin E1 (PGE1, were implanted into the cerebral ventricle ipsilateral to the lesion, and then irrigated with DBcAMP administered through a totally implanted drug delivery system. The effect of the implant decreased after the second week. Neuroblastoma cells were found in approximately 50% of the implanted animals. TH immunostaining was weak or absent in the grafted animals. Inflammatory changes were present in the majority of the brains examined. Extensive tumor growth was present in one animal implanted with untreated cells. Grafting of cells treated with DBcAMP and PGE1 plus with mitomycin C and bromodeoxyuridine in animals immunosuppressed with cyclosporin A reduced the apomorphine-induced rotation to 40-60% of baseline levels and this reduction persisted beyond the period of infusion with DBcAMP. Intraventricular infusion of DBcAMP in animals injected with cell culture medium produced a transient reduction of rotation to 70% of baseline. The amphetamine-induced rotation was not significantly reduced during the 4 weeks follow up. Atypical cells, consistent with surviving neuroblastoma cells, were observed in the brain of all transplanted animals. TH immunostaining was weak or negative in most cases. Human neuroblastoma cells may be an alternative donor tissue for the study of the effects of transplantation in animal models of Parkinson's disease.
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PMID:Biochemical properties of monoamine-rich human neuroblastoma cells. 256 96

Neuroblastoma clones were examined for choline acetyltransferase (EC 2.3.1.6), tyrosine hydroxylase (EC 1.14.3.a), acetylcholinesterase (EC 3.1.1.7), and also for neurite formation. One clone does not form axons or dendrites. Three types of clones were found with respect to neurotransmitter synthesis: cholinergic, adrenergic, and clones that do not synthesize acetylcholine or catechols. All clones contain acetylcholinesterase. These results show that genes determining neurotransmitter species can be expressed in dividing cells, that the parental programs of gene expression are inherited, and that dividing cells can be programmed with respect to their ability to communicate with other cells.
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PMID:Neurotransmitter synthesis by neuroblastoma clones (neuroblast differentiation-cell culture-choline acetyltransferase-acetylcholinesterase-tyrosine hydroxylase-axons-dendrites). 440 Feb 94

Neuroblastoma (NB) is a tumor which arises from neural crest cells. In the developing neural crest cells, the induction of 3,4-dihydroxyphenylalanine (DOPA) decarboxylase is more delayed than that of tyrosine hydroxylase and dopamine-beta-hydroxylase. If NB cells are arrested in an early stage of neural crest development, the induction of DOPA decarboxylase is insufficient and the accumulation and secretion of DOPA can be caused. The biochemically immature phenotype is thought to represent the undifferentiated characteristics of the cells and might correlate with the grade of malignancy. To investigate whether the hypothesis is clinically applicable or not, we have measured plasma DOPA, dopamine and urinary catecholamine metabolites in NB patients. The levels of plasma DOPA, dopamine, urinary homovanillic acid (HVA) and vanillactic acid (VLA) were significantly higher in patients with unfavorable NBs and the higher plasma DOPA level was significantly associated with the patients' age (> 1 year old), tumor stage (III, IV) and DNA diploidy. Serial determination of plasma DOPA was a good monitor of the disease course. These results are compatible with the hypothesis on DOPA decarboxylase deficiency and DOPA secretion in undifferentiated, unfavorable NBs. In conclusion, the plasma DOPA can be used to predict patients' prognosis as well as to follow up patients with NB.
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PMID:3,4-dihydroxyphenylalanine (DOPA) decarboxylase deficiency and resultant high levels of plasma DOPA and dopamine in unfavorable neuroblastoma. 852 65

Neuroblastoma is a malignant solid tumor of childhood with a poor prognosis. The growth of solid tumors has been shown to be dependent on new blood vessel formation, i.e. angiogenesis. Several steps in the metastatic process have also been found to be angiogenesis-dependent. Neuroblastomas grow quickly, are highly vascularized, and metastasize early, and hence inhibition of angiogenesis--angiostatic therapy--may be indicated in this disease. In order to investigate the effects of angiostatic agents in this disease, a new animal experimental model for human neuroblastoma was developed. Three angiostatic agents were tested in the model: TNP-470, the synthetic analogue of fumagillin, given subcutaneously, and the endogenous steroid 2-methoxyestradiol and its derivative 2-propynylestradiol, given orally. TNP-470 administration resulted in a significant reduction of the tumor growth rate and microvascular counts, and of the fraction of viable tumor cells, compared to controls. The fraction of apoptotic tumor cells increased threefold, while that of proliferative cells remained unaltered. This can explain the reduced net growth. Treatment with the angiostatic and chemotherapeutic steroids 2-methoxyestradiol and 2-propynylestradiol yielded similar results. However, the mechanism of action of these steroids was bimodal; the effect occurring both through inhibition of tumor angiogenesis and through induction of tumor cell apoptosis. It was shown for the first time that inhibition of angiogenesis regardless of agent induces striking chromaffin differentiation, observed as increased expression of insulin-like growth factor II gene, tyrosine hydroxylase, and chromogranin A, and increased formation of cellular processes. It is suggested that inhibition of angiogenesis induces metabolic stress, resulting in chromaffin differentiation and apoptosis. Such agonal differentiation may be the link between angiostatic therapy and tumor cell apoptosis. Angiostatic agents administered as single therapy have an objective tumoristatic effect in our neuroblastoma model. Angiostatic treatment of neuroblastoma is a new and promising treatment modality that merits clinical investigation.
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PMID:Angiostatic treatment of neuroblastoma. 1037 67

Neuroblastoma originates from neural crest cells and is the most common extracranial solid tumor in childhood. Bone metastasis in neuroblastoma is an unfavorable prognostic factor even with intensive therapy. In the present study, we screened four cell lines of human neuroblastoma (NB-1, NB-16, NB-19, and NH-6) for tumorigenicity and metastatic capacity in nude mice and found that NB-19 cells caused osteolytic lesions after s.c. injection into mice. To detect micrometastases in the host tissue, we performed two kinds of PCR-based metastasis assays: (a) genomic PCR assay using the primers for human genome-specific Alu sequence; and (b) reverse transcription-nested PCR assay that detects the expression of tyrosine hydroxylase, a marker specific for neuroblastoma. The results of these PCR assays revealed the colonization of human neuroblastoma cells in the bone marrow of the mice that had received the s.c. injection of NB-19 cells. Because osteoclastic bone resorption has been reported to play important roles in osteolysis in some cancers such as breast cancer, we next examined the osteoclast (OC)-inducing activity of NB-19 cells using a coculture system in which NB-19 cells were cultured with murine bone marrow cells containing OC precursors and stromal cells. NB-19 cells induced tartrate-resistant acid phosphatase-positive multinucleated OC-like cells without requirement of 1,25-dihydroxyvitamin D3 or other osteoclastogenic stimulators. To investigate the factors involved in the osteoclastogenesis in the coculture of mouse marrow cells and NB-19 cells, we performed reverse transcription-PCR analysis and revealed the increased expression of receptor activator of nuclear factor kappaB ligand (RANKL) in the coculture compared with the culture of bone marrow cells alone. Interleukin-1alpha and cyclooxygenase-2 expression in the murine marrow cells was also increased in the presence of NB-19 cells. To further study the role of RANKL in the OC-like cell formation in the coculture of NB-19 cells and murine marrow cells, an expression vector encoding the active portion of the murine osteoprotegerin, which is the native inhibitor of RANKL action, was constructed and introduced into COS-7 cells. The conditioned media of the COS-7 cells transfected with the osteoprotegerin expression vector effectively blocked OC-like cell formation in the coculture of the bone marrow cells and NB-19 cells. These results suggested that in the bone microenvironment of NB-19-bearing mice, the stimulated expression of RANKL plays an important role in OC formation, leading to osteolytic bone metastasis.
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PMID:Receptor activator of nuclear factor kappaB ligand (RANKL) is a key molecule of osteoclast formation for bone metastasis in a newly developed model of human neuroblastoma. 1124 77

Insufficient oxygen and nutrient supply often restrain solid tumor growth, and the hypoxia-inducible factors (HIF) 1 alpha and HIF-2 alpha are key transcription regulators of phenotypic adaptation to low oxygen levels. Moreover, mouse gene disruption studies have implicated HIF-2 alpha in embryonic regulation of tyrosine hydroxylase, a hallmark gene of the sympathetic nervous system. Neuroblastoma tumors originate from immature sympathetic cells, and therefore we investigated the effect of hypoxia on the differentiation status of human neuroblastoma cells. Hypoxia stabilized HIF-1 alpha and HIF-2 alpha proteins and activated the expression of known hypoxia-induced genes, such as vascular endothelial growth factor and tyrosine hydroxylase. These changes in gene expression also occurred in hypoxic regions of experimental neuroblastoma xenografts grown in mice. In contrast, hypoxia decreased the expression of several neuronal/neuroendocrine marker genes but induced genes expressed in neural crest sympathetic progenitors, for instance c-kit and Notch-1. Thus, hypoxia apparently causes dedifferentiation both in vitro and in vivo. These findings suggest a novel mechanism for selection of highly malignant tumor cells with stem-cell characteristics.
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PMID:Hypoxia alters gene expression in human neuroblastoma cells toward an immature and neural crest-like phenotype. 1201 61

Neuroblastoma (NB) is characterised by the secretion of catecholamines in approximately 95% of patients. Tyrosine hydroxylase is the rate-limiting enzyme in catecholamine biosynthesis pathway. Expression of the tyrosine hydroxylase gene (TH) is regulated in a tissue-specific manner during neonatal development and differentiation, therefore TH mRNA expression is a specific tumour marker for NB. Here we present a real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay using TaqMan technology for detection and quantification of TH mRNA in bone marrow (BM) NB patients. The degree of TH expression was derived from the ratio of the mRNAs of this gene and the reference gene, beta-actin. A ratio greater than 3x10(-2) was considered as positive for TH mRNA presence. Samples were also examined for TH mRNA by first and nested RT-PCR. Seventeen BM samples from 4 patients with disseminated NB (3 stage IV and 1 stage IVs) were evaluated at diagnosis and during treatment. We found a variable degree of TH expression ranging from 0.0344 to 26.3370 in 12/17 positive samples, while no TH mRNA (value lower than 3x10(-2)) was detected in 5/17 samples obtained after consolidation therapy. Our results show a moderate concordance between different qualitative RT-PCR methods and real-time RT-PCR. The real-time RT-PCR results seem to fit better with the natural short-term clinical follow-up of the evaluated patients, with respect to qualitative methods. Real-time TH RT-PCR could therefore be of clinical value for the assessment of a patient's prognosis by monitoring minimal residual disease (MRD).
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PMID:Real-time RT-PCR of tyrosine hydroxylase to detect bone marrow involvement in advanced neuroblastoma. 1257 72

Neuroblastoma, a tumor originating from the sympathetic nervous system, is the most common extracranial malignant solid tumor of childhood. Human neuroblastoma cells may differentiate in vitro under treatment with a variety of biological agents and drugs. Among these, retinoic acid (RA) is quite potent and its effectiveness as a therapeutic agent is now being evaluated in clinical trials. As its pleiotropic biological activities may produce side-effects limiting clinical use, it is important to find new compounds that present the same effectiveness together with few side-effects. In this study we have explored the action of IIF, (pat. WIPO W0 00/17143) a new derivative of RA, as a differentiation inducer in the human neuroblastoma cell line TS12. In the same cell line, we have also compared the effect of IIF with that of all trans RA (ATRA) and of 9 cis RA (9cRA), with respect to morphological and biochemical differentiation and growth inhibition. Treatment with IIF resulted in a strong inhibition of proliferation and in a marked induction of neuronal differentiation as revealed by neurite extension, increase of actylcholinesterase (AchE) specific activity and tyrosine hydroxylase (TH) expression. The results demonstrate the effectiveness of this new retinoid as a differentiation inducer on neuroblastoma cells TS12. Furthermore, the differentiation-promoter and antimitotic activities of IIF were on the whole more pronounced than those of ATRA and 9cRA. Therefore our study suggests the evaluation of the new retinoid IIF as a therapeutic approach in the treatment of neuroblastoma.
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PMID:Effect of a new derivative of retinoic acid on proliferation and differentiation in human neuroblastoma cells. 1282 Apr 15

Neuroblastoma, the third most common tumor of childhood, is a complex disease in which few genetic mutations have been identified.Mice expressing a human MYCN oncogene driven by the rat tyrosine hydroxylase promoter (TH-MYCN) represent an animal model for this disorder. We performed microarray-based comparative genomic hybridization analysis on murine tumors, identifying gains on chromosomes 1, 3, 11, 14, 17, and 18 and losses on chromosomes 5, 9, and 16. Fluorescence in situ hybridization analysis confirmed an amplicon on chromosome 18 as the site of TH-MYCN transgene integration. Selected tumors with localized gains of chromosome 11 delineate a 15-Mb region orthologous to human chromosome 17q and help to narrow the minimal region gained in human tumors. We observed clustered loss of chromosomes 5, 9, and 16, orthologous to a similar pattern of combined loss of chromosomes 3p, 4p, and 11q in human tumors. These data demonstrate conservation of many genetic changes in murine and human neuroblastoma and suggest that further delineation of genetic abnormalities in murine tumors may identify genes important in human disease.
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PMID:Genome-wide array CGH analysis of murine neuroblastoma reveals distinct genomic aberrations which parallel those in human tumors. 1450 Mar 57


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