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)

In 31 families of xeroderma pigmentosum (XP) patients, significantly more blood relatives than spouse controls had had nonmelanoma skin cancer. These family data support the hypothesis that heterozygosity for XP genes may predispose persons to skin cancer, particularly in association with substantial exposure to sunlight.
J Natl Cancer Inst 1979 Jun
PMID:Cancer in families with xeroderma pigmentosum. 28 13

This study of identical twins affected with xeroderma pigmentosum, with follow-up and re-evaluation after a period of eight years, is unique in that it demonstrates clearly the value of cancer control methods, primarily the avoidance of solar radiation. The findings in the identical twins have been evaluated in context with their other affected siblings who also have shown a remarkable low rate of skin cancer upon initiation of cancer control (solar radiation avoidance).
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PMID:Cancer control in xeroderma pigmentosum. 30 3

The sensitivity of cultured fibroblasts obtained from four unrelated Xeroderma pigmentosum patients (XP-K, XP-C, XP-E and XP-H), which showed different DNA repair levels, was examined. The frequency of metaphase plates with chromosome aberrations and the frequency of breaks and exchanges per chromosome complement were estimated following exposure to the carcinogens 4-nitroquinoline-1-oxide (4NQO),N-acetoxy-2-acetyl-aminofluorene (N-acetoxy-2-AAF), and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and to the mutagen daunomycin. The frequency of chromosome aberrations (breaks and exchanges) increased in the order (XP-K less than XP-C less than XP-E less than XP-H) with decreasing DNA repair capacity of the XP cells examined (XP-K greater than XP-C greater than XP-E greater than XP-H) following 4NQO and N-acetoxy-2-AAF. MNNG induced DNA repair synthesis and chromosome aberrations in the four XP cell types at levels comparable to those in fibroblasts of non-afflicted persons. Daunomycin triggered no DNA repair synthesis but induced similar frequencies of chromosome aberrations in the XP cells and controls. Heterozygous XP cells from parents of XP-K, XP-E and XP-C responded as control cells towards the three carcinogens and the mutagen used. Xeroderma pigmentosum can be considered to be an "induced" chromosome instability syndrome, in contrast to Bloom's syndrome or Fanconi's anaemia, which are "spontaneous" chromosome breakage syndromes according to German's definition.
Int J Cancer 1977 Aug 15
PMID:Differential sensitivity of Xeroderma pigmentosum cells of different repair capacities towards the chromosome breaking action of carcinogens and mutagens. 40 78

Xeroderma pigmentosum (XP) cells proficient in the excision repair of pyrimidine dimers (XP variants) were also found to be proficient in the excision repair of N-2-acetoxyacetylaminofluorene (AAAF)-induced lesions in their DNA, as assayed by the photolysis of 5-bromodeoxyuridine incorporated during repair. However, the time in which the small segments of newly synthesized DNA, made immediately after treatment of cells with AAAF, were joined together to form DNA of parental size by a process called postreplication repair was long in the XP variant and classical cells. Although increasing doses of AAAF increased the time for making daughter DNA of parental size for variant and classical XP cells, AAAF did not appear to affect this process in normal human cells. Treatment of variant and classical XP cells with a relatively small dose (2.5 micron) of AAAF or 2.5 J/sq m of UV radiation several hr before a 2- to 3-fold-larger dose decreased the time for the pulse-labeled DNA to appear as parental size.
Cancer Res 1978 Apr
PMID:Defective and enhanced postreplication repair in classical and variant xeroderma pigmentosum cells treated with N-acetoxy-2-acetylaminofluorene. 63 41

Fibroblasts from New Zealand Black mouse fetuses manifest increased frequency of chromosomal breaks and interchanges after exposure to ultraviolet radiation when compared with cells from BABL/c fetuses. This chromosomal instability is similar to what has been reported in cells from patients with xeroderma pigmentosum and may be related to the chromosomally abnormal clones and malignancy previously reported in adult New Zealand Black mice.
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PMID:Ultraviolet radiation--induced chromosomal abnormalities in fetal fibroblasts from New Zealand black mice. 68 17

Xeroderma pigmentosum (XP) is a rare inherited, heterogeneous syndrome with pigment anomalies, sun sensitivity, multiple cutaneous neoplasms and abnormal self protecting systems (SPS). The transmittence is autosomal-recessive. 50 percent of XP patients gets melanoma and 15 percent have neurological abnormalities. Clinical differentiation, determination of the DNA repair rate and cell fusion studies allow the differentiation of 6 complementation groups including De Sanctis-Cacchione syndrome and the XP variant typ. Pigmented Xerodermoid is a special form. Cytogenetic studies give evidences for the model character of XP for UV carcinogenesis.
Bull Cancer 1978
PMID:Xeroderma pigmentosum: heterogeneous syndrome and model for UV carcinogenesis. 71 83

Biochemical and genetic information on xeroderma pigmentosum (XP) has been briefly reviewed. This indicates that 80 to 90 percent of all XP patients are defective in the excision repair of pyrimidine dimers and are unable to perform the first step of this process as shown, for example, by their inability to undergo the DNA superhelical changes which accompany the initiation of excision repair in normal cells. However, in spite of its apparent biochemical homogeneity, XP is genetically heterogeneous and many genes appear to be responsible for the function of the factor defective in XP. Ten to 20 percent of all XP patients (called XP-variants) are capable of "dimer excision repair" but have difficulties in replicating UV-damaged DNA. The defects of XP and XP-variant affect also the repair of DNA damage caused by a number of chemical mutagens and carcinogens. This has important theoretical and practical implications since it indicates, for example, that the repair systems defective in XP must have broad specificity and that even XP cells not exposed to the harmful effect of light may suffer from poor repair of DNA damage. With regard to cancer, two questions have been considered. Namely, does XP provide a valid general model for UV-carcinogenesis in man and does it show how DNA damage leads to malignant transformation? The first question was answered in the affirmative in view of some clinical but, mainly, of cell biological data indicating that normal and excision defective XP cells differ, more quantitatively than qualitatively, in their response to UV-light. With regard to the second question XP seems to provide some support for various theories on carcinogenesis and, DNA repair defects may favour actinic carcinogenesis in a complex, non-univocous manner. Possibly the most important lesson imparted by XP is that, in man, the stability of the genetic material is dependent on the function of repair systems whose failure may predispose to cancer. In addition, the study of XP has stressed the fact that many genes control DNA metabolism and new evidence is accumulating to show that defects in such genes may contribute significantly to the genetic predisposition to cancer.
Bull Cancer 1978
PMID:Xeroderma pigmentosum and the role of DNA repair in oncogenesis. 71 84

Pigmented Xerodermoid is a variant of Xeroderma pigmentosum characterized by late manifestation of sun--sensitivity, dyschromic and poikilodermatic skin changes and multiple malignant skin tumors in light exposed areas. In contrast to Xeroderma pigmentosum excision repair system is normal, but DNA synthesis after UV--irradiation is markedly prolonged, suggesting that the postreplicational repair mechanism is disturbed. A family of 89 members with 4 siblings suffering from pigmented Xerodermoid was examined. The pedigree of this family suggests autosomal recessive inheritance in this disease.
Bull Cancer 1978
PMID:Pigmented Xerodermoid: first report of a family. 71 86

We used three techniques to examine excision repair in human cells treated with ultraviolet radiation, N-acetoxy-2-acetylaminofluorene, and a combination of the two. The three techniques gave similar results. Two types of human cells were used: (a) excision repair proficient (normal human fibroblasts and xeroderma pigmentosum variants); and (b) excision repair deficient (xeroderma pigmentosum C, D, and E). Saturation doses were determined and used for combined treatments with both agents. We observed two patterns of repair: (a) in repair-proficient cells total repair was additive; and (b) in repair-deficient cells total repair was much less than additive (usually less than that repair was much less than additive (usually less than that observed for separate treatments) and N-acetoxy-2-acetylaminofluorene inhibited excision of pyrimidine dimers. We conclude that, in the first group of cells, pathways for repair of ultraviolet radiation- and N-acetoxy-2-acetylaminofluorene-induced lesions are not identical and, in the second group of cells, there is an inhibitory effect exerted by major or minor products of each agent on the repair enzyme(s) of the other.
Cancer Res 1979 Feb
PMID:DNA repair in xeroderma pigmentosum cells treated with combinations of ultraviolet radiation and N-acetoxy-2-acetylaminofluorene. 76 Dec 20

Excision-repair of DNA base damage produced by 4-nitroquinoline-1-oxide (4NQO) was compared in Escherichia coli, human cells, and mouse cells. Paper chromotography of acid hydrolysates of DNA extracted from cells treated with 3H-labeled 4NQO revealed four peaks; two kinds of 4NQO-guanine adduct, one kind of 4NQO-adenine adduct, and free 4-aminoquinoline-1-oxide (4AQO). About 80% of the initially formed 4NQO-purine adducts were excised from DNA in E. coli uvrA+ cells during 60 min postincubation, but not at all in uvrA- (excisionless for uv damage) cells. Normal human cells excised about 60% of 4NQO-purine adducts during 24 hr postincubation, but xeroderma pigmentosum (excisionless) cells did not. A mouse cell line susceptible to repair of 4NQO-induced pretransformational damage also showed excision-repair ability for the 4NQO adducts. From these and other results, we conclude that the 4NQO-purine adducts and unstable 4NQO-guanine products (which release 4AQO) are, like pyrimidine dimers, repairable by excision-repair universal among E. coli, mouse, and human being, and that unexcised ones are probably the major cause of killing, mutation, and cancer.
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PMID:Excision-repair of 4-nitroquinolin-1-oxide damage responsible for killing, mutation, and cancer. 81 Dec 13


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