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)

We have previously isolated long-range acting enhancer elements from the HeLa genome by functional selection. In this report, the structural and functional characteristics of one (GA1) of the enhancers are reported. By cloning various restriction fragments and by deletion mutagenesis, the activity of GA1 was located in a 230-bp region. The nucleotide sequence of GA1 and genomic Southern blot analysis indicated that GA1 is derived from human papilloma virus (HPV) 18 DNA that had been integrated into the HeLa genome. The enhancer is located in the non-coding region of the HPV 18 genome. The HPV 18 enhancer consists of two functional domains, both of which have full enhancer activity in HeLa cells. The enhancer does not contain enhancer core sequences but contains several blocks of potential Z-DNA sequence. Like SV40 and polyoma virus enhancers, the activity of the HPV 18 enhancer was repressed by adenovirus E1a products. The HPV 18 enhancer shows a narrow cell type specificity: it is active in some cervical carcinoma cell lines, but inactive in all non-cervical cells except for one neuroblastoma cell line. These results suggest that the HPV 18 enhancer plays an important role in regulation of the viral genes.
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PMID:Characterization of a cell type-specific enhancer found in the human papilloma virus type 18 genome. 303 18

Neuroblastoma-derived tumor cells, unlike cells from other tumor types, characteristically express a wildtype but cytoplasmically sequestered p53 protein. To ascertain whether the p53 in these cells retained any physiological activity, we inactivated it in SK-N-SH cells, a neuroblastoma-derived cell line, by introducing the human papilloma virus type 16 E6 expression plasmid. Parent SK-N-SH cell cultures are composed of two cell types exhibiting characteristic morphologies designated neuroblastic (N-type) or substrate-adherent fibroblastic (S-type) cells, both of which have been shown to spontaneously transdifferentiate or interconvert. We report here that down-regulation of p53 resulted in conversion of SK-N-SH cells to the substrate-adherent fibroblast-like S-type cells. The morphologic conversion was accompanied by a loss of neurofilament expression, a marker for the neuronal N-type cells, an increase in the expression of vimentin, and a lack of responsiveness to retinoic acid-induced neuronal differentiation. Importantly, we did not observe N-type cells in the E6-transfected cell population, suggesting that they were incapable of transdifferentiating to the N-type morphology. We also tested the ability of these E6-transfected S-type cells to form colonies in soft agar and observed a markedly reduced capacity of these cells to do so when compared with the parent and mutant E6-transfected cells. These results suggest that p53 is required for the maintenance of the neuroblastic tumorigenic phenotype.
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PMID:Morphologic conversion of a neuroblastoma-derived cell line by E6-mediated p53 degradation. 1120 42

In the present study we review ENT tumor pathology in childhood. Only the most salient aspects are emphasized and the variety of entities reviewed was restricted. Molecular biology techniques reveal infection by human papilloma virus (types 6 and 11) in 50 % of papillomas, while immunohistochemical techniques are less effective in papilloma virus detection. The myofibroblastic nature of nasal angiofibroma has been demonstrated and its incidence is 25 times more frequent in patients with familial polyposis of the colon. Overexpression of p53 occurs in the initial stages of nasopharyngeal carcinoma, while overexpression of c-myc is correlated with an unfavorable prognosis. Recently, olfactory neuroblastoma has been shown not to express the protein product of the MIC-2 gene (antibody 12E7), thus the hypothesis that it could be a member of the Ewing tumor family (neuroectodermal peripheral tumors) has not been confirmed, although it is a primitive neural tumor. The head and neck rhabdomyosarcoma with the best prognosis is that located in the orbit, and cytogenetic studies have shown chromosomic translocation t(2;13) in 50 % of these childhood tumors when they are of the alveolar-type, while trisomy of chromosome 2 or 20 is more characteristic of the embryonic-type. Currently, any classifying features of ENT lymphomas must be based on the Revised European-American Classification of Lymphoid Neoplasms (REAL). Papillary and medullary carcinomas are the most common histological types of thyroid carcinoma in childhood. Alterations in ret/PTC play a significant role in the pathogenesis of both.
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PMID:[Advances in the diagnosis of ENT tumors in childhood]. 1272 79

The Ras/Raf/MEK/ERK (MAPK) signal transduction cascade is an important mediator of a number of cellular fates including growth, survival and apoptosis. The aim of this study was to determine the incidence of B-raf, Kirsten-ras (K-ras) and Neuroblastoma-ras (N-ras) gene mutations in esophageal squamous cell carcinoma (ESCC) in the Greek population. DNA was extracted from 30 ESCC and 32 normal esophageal specimens and screened for V600E B-raf, and K-ras/N-ras codon 12 mutations, by PCR-RFLP based analysis. Among the genes tested, only the heterozygous K-ras mutation was detected in 5 out of the 30 ESCC specimens (16%), whereas no mutation was found in the normal esophageal tissue (P < 0.022). The normal samples were screened negative for N-ras and V600E B-raf mutations. The increased risk of esophageal cancer was correlated with tobacco use (OR = 3.5, P < 0.023) and alcohol abuse (OR = 7.22, P < 0.001), accompanied with the high incidence of the k-ras codon 12 mutation (22%, OR = 1.77 and 21%, OR = 1.52), respectively. A similar positive association was seen in human papilloma virus (HPV)-infected patients (OR = 5.66, P < 0.003). Our overall findings demonstrate that the mutational activation of the K-ras gene, HPV infection and tobacco or alcohol abuse, can be considered independently or in combination as high risk factors for ESCC development.
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PMID:K-ras mutation, HPV infection and smoking or alcohol abuse positively correlate with esophageal squamous carcinoma. 1859 5