Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several autosomal recessive diseases are associated with apparent DNA repair defects in cell culture. It seemed likely that a defect in excision repair reported for ataxia telangiectasia cells might reflect a lack of apurinic endonuclease activity. We report here normal levels of apurinic endonuclease activity in extracts of cell lines derived from patients with ataxia telangiectasia, xeroderma pigmentosum (complementation group D), Cockayne dwarfism, Fanconi anemia and Bloom syndrome.
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PMID:Apurinic DNA endonuclease activities in repair-deficient human cell lines. 63 94

UV-sensitivity is a common feature of several diseases including Xeroderma pigmentosum (XP), Cockayne syndrome (CS) and Bloom syndrome (BS). In 12 children with such diseases, cell viability and DNA repair following UV-irradiation as well as PHA transformation of lymphocytes were studied. In 5 of 6 XP cases, in 1 child with CS and in 1 of 2 children with BS, DNA repair and PHA transformation of lymphocytes showed extremely depressed values. A similar study was performed in 2 children with a rare association of XP and CS. Results suggest a relationship between these 2 diseases
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PMID:[Photosensitization and DNA repair. Possible nosologic relationship between Xeroderma pigmentosum and Cockayne's syndrome]. 74 55

The frequency of BrdU-induced sister chromatid exchanges (SCE) in cultured lymphocytes from patients with ataxia telangiectasia, Werner syndrome, and xeroderma pigmentosum was normal. The rate was increased in xeroderma pigmentosum following exposure to ultraviolet light and spontaneously raised in the Bloom syndrome. Quadriradial exchanges between homologous chromosomes in Bloom syndrome not only involve sister chromatids but also homologous (non-sister) chromatids. This could result in the formation of recombinant chromosomes and is viewed as a genetically determined form of increased somatic recombination in man. Endoreduplicated metaphases showed 'twin' and 'single' exchanges in a 1:2 ratio. This suggests a comparable frequency of exchanges at both divisions and provides evidence for the polarity of the chromatid subunits and the presence of a single chain of DNA.
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PMID:Chromatid exchanges in ataxia telangiectasia, Bloom syndrome, Werner syndrome, and xeroderma pigmentosum. 96 24

The familial occurrence of head and neck cancers supports the role of heredity in this disease group. The roles of environmental and genetic factors are difficult to separate. There are several well-characterized entities, however, that are associated with risk and prognosis of head and neck cancer, including Lynch-II syndrome, Bloom syndrome, Fanconi's anemia, xeroderma pigmentosum, ataxia telangiectasia, and Li-Fraumeni syndrome. Mutagen-induced chromosomal damage is associated with an increased risk of multiple primary neoplasms and upper aerodigestive tract cancers. A possible reduction of genotoxicity, mediated by micronutrients, was demonstrated in vitro. Sister chromatid exchanges and micronuclei are useful exposure and disease markers. Metabolic changes (acetylation, DBQ phenotype, and the AH locus polymorphism) have been found to be associated with cancer of the upper aerodigestive tract. Most associations between histocompatibility antigens and solid tumors are relatively weak, probably because of the masking effects of environmental factors. Infections by HPV, EBV, and HSV have a causative or predisposing role in several types of head and neck cancer. Amplification and rearrangement of oncogenes may also play a role in carcinogenesis, and oncogene amplification may be associated with aggressive tumor behavior and unfavorable clinical prognosis. Ploidy of tumors seems to be an important determinant of survival and response to therapy.
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PMID:Hereditary and environmental factors associated with risk and progression of head and neck cancer. 140 93

A cytogenetic observation, that the sister chromatid exchanges (SCE) occur 3 times more frequently in a special form of xeroderma pigmentosum--XPII than in the norm, prompted a study of DNA replication in this rare disease. Using DNA fiber autoradiography, the rate of fork movement and the frequency of initiation in the adjacent clusters of replicons were estimated. The rate of fork movement was significantly slower than that in classical XP and in normal cells. Here evidence was provided on another defect in DNA replication in XPII that involves a significantly decreased number of simultaneously operating adjacent clusters of replicons, which results in a decreased rate of DNA chain-growth. According to the Painter replication model for SCE, the exchanges arise due to double-strand DNA breaks occurring on the border between two adjacent clusters, respectively, completely and partially replicated. A retarded fork-displacement rate together with a decreased rate of DNA-chain growth may cause this situation to persist longer than in the norm. Thus, our data provide a further support of the replication model for SCE. A similar combination of cytogenetic and molecular defects has been obtained earlier in the Bloom syndrome cells.
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PMID:[The interrelation between changes in the structural organization of replicon clusters, a retarded fork displacement rate and the high level of spontaneous SCEs in form II of xeroderma pigmentosum]. 145 62

It has long been recognized that exposure to specific chemical and physical agents can result in the appearance of tumours in both man and animals. There is substantial evidence that DNA is the ultimate cellular target of carcinogens and that DNA repair is an important cellular defence against the effects of carcinogen exposure. Some insight into the molecular processes involved in cellular responses to carcinogens is provided by the occurrence of rare human disorders that display complex abnormalities in processing DNA damage or maintaining genomic integrity. These disorders include xeroderma pigmentosum, Cockayne syndrome, ataxia telangiectasia, dysplastic nevus syndrome and Bloom syndrome. Such disorders have provided clues to some of the basic mechanisms involved in carcinogenesis.
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PMID:Carcinogenesis: molecular defences against carcinogens. 186 47

The present studies confirm that diesel exhaust emissions are mutagenic in bacterial and mammalian mutation assays. Our results further indicate that mutagenic potential of the diesel tar samples can be reduced by exogenous metabolic activation with S15, and that Epstein-Barr-virus transformed lymphoblastoid cell lines from Bloom syndrome, and Xeroderma Pigmentosum patients with a high incidence of malignant tumors showed an larger production of SCEs while those from Fanconi anemia patients had an lower frequency of SCEs when exposed to the diesel emission condensate, compared to those from normal healthy persons. On the contrary to the results of in-vitro studies, the in-vivo SCE and micronucleus assays using mouse and rat bone marrow cells gave negative responses.
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PMID:Genotoxicity of diesel exhaust emissions in a battery of in-vitro short-term and in-vivo bioassays. 243 8

Fibroblasts from patients with xeroderma pigmentosum (XP) complementation groups A, C, D, E, and G, as well as Bloom syndrome (BS) and Fanconi anemia (FA) have been transfected with a plasmid, pSV7, containing the early region of Simian virus 40 (SV40). All of the cultures exhibited cytologic changes characteristic of transformed cells and expressed T-antigen. They also contained integrated copies of DNA derived from the vector, and in several cases, extrachromosomally replicated DNA. Not all of the transfected cultures became immortalized. The transformed xeroderma pigmentosum (XP) cultures retained their UV-sensitive phenotype in all but one case. The BS and FA cell lines retained their characteristic phenotype. All of the cultures, except the BS cells, can be readily transfected with the plasmids, pSV2neo and pSV2gpt.
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PMID:Transformation of DNA repair-deficient human diploid fibroblasts with a simian virus 40 plasmid. 303 Jul 88

We reported previously that human cells after neoplastic transformation in culture had acquired an increased susceptibility to chromatid damage induced by x-irradiation during the G2 phase of the cell cycle. Evidence suggested that this results from deficient DNA repair during G2 phase. Cells derived from human tumors also showed enhanced G2-phase chromosomal radiosensitivity. Furthermore, skin fibroblasts from individuals with genetic diseases predisposing to a high risk of cancer, including ataxia-telangiectasia, Bloom syndrome, Fanconi anemia, and xeroderma pigmentosum exhibited enhanced G2-phase chromosomal radiosensitivity. The present study shows that apparently normal skin fibroblasts from individuals with familial cancer--i.e., from families with a history of neoplastic disease--also exhibit enhanced G2-phase chromosomal radiosensitivity. This radiosensitivity appears, therefore, to be associated with both a genetic predisposition to cancer and a malignant neoplastic state. Furthermore, enhanced G2-phase chromosomal radiosensitivity may provide the basis for an assay to detect genetic susceptibility to cancer.
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PMID:Chromosomal radiosensitivity during the G2 cell-cycle period of skin fibroblasts from individuals with familial cancer. 386 Aug 70

We have examined the conversion of intermediates of DNA replication in normal human skin fibroblasts and fibroblasts isolated from patients with genetic diseases caused by putative DNA repair defects. Experiments were performed in non-transformed, unchallenged cells using alkaline sucrose sedimentation analysis to demonstrate precursor low molecular weight (LMW) DNA molecules which converted into high molecular weight (HMW) DNA with time. Analyses of conversion of replicative intermediates were conducted in cells from patients with ataxia telangiectasia (AT), Fanconi anemia (FA), Bloom syndrome (BS), Cockayne syndrome (CS) and xeroderma pigmentosum (XP). Our studies show that conversion of replicative intermediates occurs in all cell strains examined. However, XP cells (complementation groups A and E) show evidence of abnormalities in the conversion of LMW replicative intermediates, with the most dramatic alterations shown by cells from complementation group A.
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PMID:Conversion of replicative intermediates in human DNA-repair defective cells. 395 84


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