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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transgenic mice carrying a cDNA to the polyoma virus middle T (mT) antigen linked to the thymidine kinase promoter were generated to study the consequences of deregulated expression of mT-associated tyrosine kinase activity in a wide variety of tissues. Four independent transgenic founder animals were obtained, from one of which was established a transgenic line. This mouse and all its offspring developed multiple neuroblastomas between 2 and 3 months of age. Expression of the transgene (assayed by tyrosine kinase assay and in situ hybridization) was restricted to the neurons of the central and peripheral nervous tissue, probably because of a positional effect of the transgene integration. Characteristic preneoplastic lesions in the sympathetic ganglia and in the adrenal medulla were identified from which the neuroblastomas originated. The tumors arising in these mice show striking analogies to human neuroblastomas, including the sites of development of the tumors, their histological and ultrastructural appearance, and the expression of diagnostic markers, such as synaptophysin, and high expression of the N-myc oncogene. This animal model thus provides a unique tool for studying growth control in sympathetic neuroblasts and the pathogenesis of neuroblastoma.
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PMID:Sympathetic hyperplasia and neuroblastomas in transgenic mice expressing polyoma middle T antigen. 208 3

A solution hybridization method for the quantification of specific mRNAs is described. This assay utilizes complementary RNA probes prepared by in vitro transcription, sandwich hybridization in solution, and affinity-based hybrid collection. The possibility of using this method for crude biological samples without purifying mRNAs makes it ideal when accurate quantification of multiple samples is needed. Human N-myc oncogene transcript was used as a model and as little as 0.24 pg (2 X 10(5) molecules) of N-myc mRNA could be detected. Using this assay it was shown that human neuroblastoma IMR-32 cells contain approximately 500 N-myc mRNA molecules per cell having a half-life of approximately 35 min.
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PMID:A solution hybridization method for quantification of mRNAs: determining the amount and stability of oncogene mRNA. 209 99

1. Neuroblastoma (NB) is an unusual neuroectodermal tumor showing a high degree of spontaneous regression. NB cells can be induced to differentiate in vitro by various agents. Cell differentiation results in morphological changes characteristic of the mature neuronal phenotype, including outgrowth of neurite-like structures with several interconnections. 2. Recent experiments indicate that morphological differentiation of NB cells is associated with changes in expression of N-myc, c-myc, and c-myb oncogenes and synthesis of neurofilament proteins. However, little is known about the transcription of neurofilament genes during differentiation. 3. We have analyzed the expression of both the N-myc oncogene and mid-size neurofilament (NF) genes in the LAN-1 human NB cell line, cultured in the presence of retinoic acid (RA). Continuous treatment with RA induced morphological differentiation within 5-6 days. The transcription of N-myc was down-modulated within 24 hr of the initial exposure to RA. The mid-size NF mRNA was increased at this time. The expression of N-myc was not modified in serum-deprived LAN-1 cells, indicating that N-myc transcription is unaffected by the arrest of the cells in the G1 phase. 4. We conclude that new synthesis of mid-size NF mRNA and a decrease in N-myc transcription precede de novo formation of neurite-like processes and morphological cell differentiation of neuroblastoma cells.
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PMID:Different regulation of mid-size neurofilament and N-myc mRNA expression during neuroblastoma cell differentiation induced by retinoic acid. 212 47

12 primary neuroblastomas (NB) of different maturation stages, 2 ganglioneuromas (GN), and 2 neuroblastoma cell lines were analysed for RNA expression of the protooncogene N-myc and the gene encoding the nerve growth factor receptor (NGF-r) by Northern-blots, RNA-dot-blots and for receptor presence by immunohistological procedures. In 4 tumors with strongly elevated RNA expression of N-myc the NGF-r RNA expression was weak or absent. In all 8 tumors with highly increased NGF-r transcription no N-myc expression was detectable. These results, indicating an inverse relationship between N-myc and NGF-r expression, could help in establishing markers for differentiation, and thus prognosis, in neuroblastoma.
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PMID:Neuroblastoma: inverse relationship between expression of N-myc and NGF-r. 215 11

Regulation of the expression of procholecystokinin (proCCK) and proenkephalin A mRNA was studied in the human neuroblastoma cell line SK-N-MC. Cells were treated with dibutyryl-3',5'-cyclic AMP (dbcAMP), noradrenaline or isoproterenol, a beta-adrenoceptor agonist. Levels of proCCK and proenkephalin A mRNA were determined by Northern blot analysis with proCCK- and proenkephalin A-specific cRNA hybridization probes 9 h after drug treatments. ProCCK and proenkephalin A mRNA were co-expressed in SK-N-MC cells. ProCCK mRNA levels were increased 1.5-2.5 times by dbcAMP, noradrenaline and isoproterenol when compared with controls. The level of proenkephalin A mRNA increased approximately two to three times under the same drug conditions, whereas the level of N-myc mRNA did not change significantly. These results suggest that expression of proCCK and proenkephalin A mRNA may be regulated by a similar cAMP-dependent mechanism in the SK-N-MC cell line.
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PMID:Procholecystokinin and proenkephalin A mRNA expression is modulated by cyclic AMP and noradrenaline. 215 52

A neuroblastic-like cell line (NUB-20) was derived from a case of histopathologically diagnosed metastatic neuroblastoma. The metastatic tumor and nude mouse heterotransplant resembled neuroblastoma by histological criteria, in contrast to the primary tumor, which was differentially classified as Ewing's sarcoma. However, the cell line demonstrated a unique phenotype in culture with respect to morphology, immunohistochemical markers, and sensitivity to a battery of differentiation modulators. These characteristics, together with the presence of a chromosomal translocation (11;22),(q24;q12) and amplification with enhanced expression of the c-myc protooncogene rather than N-myc, established this tumor as neuroepithelioma. Neuroepithelioma is a tumor type distinct from, but related to, neuroblastoma in its development from the neural crest lineage. These results emphasize the growing importance of cytogenetic and molecular markers in the classification and characterization of human tumors.
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PMID:Importance of phenotypic and molecular characterization for identification of a neuroepithelioma tumor cell line, NUB-20. 215 99

DNA, extracted from tumours arising in 29 paediatric patients [14 neuroblastoma, 9 Wilms tumour (nephroblastoma), 6 miscellaneous] was investigated for evidence of N-myc amplification, using pNb-1, a recombinant plasmid containing a 1.0 Kb fragment homologous to the 5' end of the human N-myc gene. Within the neuroblastoma group, 4 patients had 15 or more copies of N-myc which correlated with advanced disease stage, and 3 other patients showed low grade amplification (2-5 copies). Low grade amplification was also observed in one patient with stage III unfavourable histology Wilms tumour, resistant to treatment. N-myc was present at single copy level in all other tumours studied. It is concluded that N-myc activation by amplification confers aggressive properties on a variety of embryonal tumours, rather than being restricted to initiation of neoplasia in tumours of neuroectodermal origin. A greater understanding of the complex interaction of a number of oncogenes involved in neuroblastoma may enable more effective therapeutic strategies to be devised.
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PMID:N-myc oncogene amplification in paediatric tumours. 217 80

Chromosome abnormalities found in pediatric solid tumors include deletions, translocations, homogeneously staining regions (hsr)/double minutes (dms), and ploidy abnormalities. The discovery of a 13q14 deletion found in lymphocytes of patients with retinoblastoma and developmental delay has led to the cloning of the retinoblastoma gene. Likewise the discovery of an 11p13 deletion in lymphocytes of patients with Wilms' tumor and aniridia has led to the cloning of the Wilms' tumor gene. Chromosome deletions found in tumor cells are considered to play a role on the homologous deletion of cancer suppressor genes. Recently, various translocations have been found mostly in soft tissue sarcomas; i.e. t(11;22) in Ewing's sarcoma, t(2;13) in alveolar rhabdomyosarcoma, t(3;8) in pleomorphic adenoma, t(3;12) in lipoma, t(12;16) in liposarcoma, t(12;14) in leiomyosarcoma, and t(X;18) in synovial sarcoma. These translocations provide important information on the difficult diagnosis of soft tissue sarcomas, and on the selection of chemotherapy protocol. Tumor cells in advanced stage neuroblastomas often show hsr/dms, in which N-myc amplification occurs. While near triploidy was regularly found in early-stage neuroblastomas, near-diploidy or near-tetraploidy was usually found in advanced stage tumors. Among various prognostic factors, N-myc copy numbers and tumor cell ploidies had the largest influence on the prognosis of neuroblastoma patients. Cytogenetic and molecular genetic analyses on tumor cells are becoming increasingly important for the diagnosis of pediatric solid tumors, and the prediction of the patients' prognosis.
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PMID:[Cytogenetics in pediatric solid tumors]. 217 98

A continuous tumor cell line (LAP-35) was established from a primitive neuroectodermal tumor of bone from the right tibia of a 12-year-old female. The neural character of the cell line was documented by the spontaneous growth of neurites and by the presence of several neural markers, including neuron-specific enolase (NSE), S-100 protein, neurofilaments, chromogranin A, synaptophysin and positivity to monoclonal antibodies UJ127.11, UJ13A, UJ181.4. Cell-sorter analysis showed a high expression of nerve growth factor receptor (NGFr) and major histocompatibility complex class I-related molecules. A unique cytogenetic profile was observed, including a reciprocal chromosomal translocation (rct) 11:22 (q24;q12), typically associated with Ewing's sarcoma and neuroepithelioma, and deletion of the short arm of chromosome 1 (lp-), otherwise a feature of neuroblastoma. N-myc proto-oncogene was neither amplified nor expressed, whereas the expression of c-myc was documented by northern blot analysis. These features distinguish this new cell line from previously reported neuroectodermal cell lines, identifying LAP-35 as a unique model of a group of neural bone tumors that share characteristics of neuroblastoma as well as neuroepithelioma.
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PMID:Establishment and characterization of a primitive neuroectodermal tumor of bone continuous cell line (LAP-35). 217 80

In human neuroblastoma, amplification of the N-myc oncogene is correlated with increased metastatic ability. We recently showed that transfection of the rat neuroblastoma cell line B104 with an N-myc expression vector resulted in an increase in metastatic ability and a significant reduction in the expression of major histocompatibility complex class I antigens. We examined whether N-myc causes additional phenotypic changes in these cells. We showed that expression of N-myc leads to a dramatic reduction in the levels of neural cell adhesion molecule (NCAM) polypeptides and mRNAs. Spontaneous revertants of the high N-myc phenotype were found to have regained significant levels of NCAM expression, indicating that the continued expression of N-myc is required to maintain the low NCAM phenotype. NCAM was not reduced in B104 cells transfected with the neomycin resistance vector alone, and other neuronal markers were not specifically reduced in N-myc-transfected B104 cells. As NCAM functions in cell-cell adhesion, decreased NCAM expression could contribute significantly to the increased metastatic potential of N-myc-amplified neuroblastomas.
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PMID:N-myc down regulates neural cell adhesion molecule expression in rat neuroblastoma. 218 16


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