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Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hereditary dysplastic nevus syndrome (DNS) is an autosomal dominant disorder in which affected individuals have increased numbers of dysplastic (premalignant) nevi and a greater than 100-fold increased risk of developing cutaneous melanoma. Epstein-Barr virus-transformed lymphoblastoid cell lines from patients with hereditary DNS have been shown to be hypermutable to UV radiation (M.I.R. Perera et al., Cancer Res., 46: 1005-1009, 1986). To examine the mechanism involved in this UV hypermutability, we used a shuttle vector plasmid, pZ189, which carries a 160-base pair marker gene, supF, and can replicate in human cells. pZ189 was treated with UV radiation and transfected into DNS6BE, a lymphoblastoid cell line from a patient with hereditary DNS. Plasmid survival after UV was similar with the DNS6BE line and with a lymphoblastoid cell line from a normal donor. Plasmid mutation frequency was greater with the DNS line in accord with the DNS cellular hypermutability. Base sequence analysis was performed on 69 mutated plasmids recovered from the DNS line. There were significantly more plasmids with single base substitution mutations (P less than 0.01) in comparison to UV-treated plasmids passed through normal fibroblasts. pZ189 hypermutability and an increased frequency of single base substitutions was previously found with a cell line from a melanoma-prone xeroderma pigmentosum patient. These differences may be related to the increased melanoma susceptibility in both DNS and xeroderma pigmentosum.
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PMID:Ultraviolet mutagenesis in a plasmid vector replicated in lymphoid cells from patient with the melanoma-prone disorder dysplastic nevus syndrome. 279 Aug 6

Patients with xeroderma pigmentosum (XP) have more than a 1000-fold increased risk of cutaneous melanoma. To determine if the XP DNA repair defect is present in cutaneous pigmentary cells, nevus cells and melanocytes from four large, pigmented nevi were cultured from a 12-year-old girl with XP. Cultured melanocytes showed dendritic morphologic features, contained mature melanosomes, and reacted with monoclonal antibody to tyrosinase. Nevus cells were spindle shaped and expressed nevus cell-associated antigens. Melanocytes, nevus cells, and dermal fibroblasts from the patient with XP all had a similar reduction in DNA repair: unscheduled DNA synthesis was 30% to 50% of that in normal fibroblasts following a 30 J/m2 ultraviolet dose. After a 6 J/m2 ultraviolet dose, the proliferative ability of XP nevus cells and fibroblasts was reduced to 10% of that of normal fibroblasts. This study indicates that cultured melanocytes and nevus cells express the characteristic XP DNA repair defect.
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PMID:Reduced DNA repair in cultured melanocytes and nevus cells from a patient with xeroderma pigmentosum. 291 63

Xeroderma pigmentosum (XP), is a rare, autosomal recessive disease with sun sensitivity and multiple neoplasms in association with reduced DNA repair. As a reflection of the clinical consequences of deficient DNA repair, XP serves as a model for determining the effects of proficient DNA repair. To estimate the risk of developing neoplasms in XP, we abstracted reports of 726 XP patients (from 41 countries) published from 1874 to 1982. Despite limitations of a literature survey, the XP patients under age 20 years had an estimated 2000-fold increase in frequency of basal cell and squamous cell carcinoma of the skin, of cutaneous melanoma, of cancer of the anterior eye, and of cancer of the anterior tongue, in comparison to the general population. These sites are all potentially exposed to u.v. radiation, a strong carcinogen which produces DNA damage that is poorly repaired by XP cells. XP patients under age 20 years also had an estimated 12-fold increase in occurrence of neoplasms in sites not exposed to u.v. radiation. Among the XP patients under age 40 years with internal cancer, there was a disproportionate representation of malignant neoplasms of the brain (especially sarcomas), and oral cavity (excluding tongue) compared to US whites under age 40 years. These internal neoplasms may be related to exposure to chemical environmental carcinogens that cause DNA damage which, like u.v.-induced damage, is poorly repaired by XP cells. These reports provide no evidence of an increase in XP of common lethal neoplasms such as lymphomas, or female genital tract or endocrine system cancers. These findings suggest that DNA repair plays a role in protection against u.v.-induced neoplasia and in protection against some internal neoplasms in the general population.
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PMID:DNA repair protects against cutaneous and internal neoplasia: evidence from xeroderma pigmentosum. 670 49

Between January 1956 and December 1990, 17 patients younger than 17 years with available pathological screens of de novo cutaneous melanoma, and with no other risk factors (xeroderma pigmentosum, giant congenital naevi, congenital melanoma or a proven family history of dysplastic naevus syndrome) were seen at the Gustave-Roussy Institute. The median age was 9 years and 9 months (range 2 years and 3 months-16 years and 9 months). The primary disease was located in the lower extremities in 10 cases, the trunk in five cases, and the upper extremities or head and neck in one case. The disease was localized for 10 patients at presentation (stage I), six had proven nodal metastasis (stage II) and one patient had nodal and breast metastases. The median thickness of the primary lesion was 2.89 mm (range 0.64-10). Five tumours were at level III on Clark's index, eight at level IV and four at level V. Six cases were classified as superficial spreading, two as unclassified radial growth, three nodular, three with Spitzoid cells, and three were unclassified. Two patients presented local recurrence with an initial unclassified melanoma, with a thickness greater than 2.5 mm. At a median follow-up time of 7 years, two patients had died from recurrent disease, and one patient had died from a second malignancy.
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PMID:Melanoma arising de novo in childhood: experience of the Gustave-Roussy Institute. 762 Mar 39

Xeroderma pigmentosum, Cockayne syndrome, the xeroderma pigmentosum-Cockayne syndrome complex, and trichothiodystrophy cells have defects in DNA repair and are associated with clinical and cellular hypersensitivity to ultraviolet radiation (UV). Familial dysplastic nevus syndrome cells have UV hypermutability. Although xeroderma pigmentosum and dysplastic nevus syndrome have markedly increased cancer risk. Cockayne syndrome and trichothiodystrophy do not. At the molecular level, these disorders are associated with several different genetic defects as evidenced by the existence of multiple overlapping complementation groups. Recent progress has been made in identifying the chromosomal location and cloning the defective genes in these disorders. Using plasmid shuttle vectors we have shown abnormal repair and mutagenesis of DNA damaged by 254-nm (UVC) or 295-nm (UVB) radiation or the chemical carcinogen aflatoxin in cells from patients with xeroderma pigmentosum. Although xeroderma pigmentosum cells are defective in repair of all photoproducts, Cockayne syndrome cells appear to be defective in repair of cyclobutane dimers and have normal repair of nondimer photoproducts. DNS cells have post UV plasmid hypermutability. These diseases may serve as models for examining molecular mechanisms of carcinogenesis in humans.
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PMID:Xeroderma pigmentosum and related disorders: examining the linkage between defective DNA repair and cancer. 796 92

The causes of cutaneous melanoma among children under 15 years are largely unknown. We report the findings of an epidemiological study of childhood melanoma in Queensland, Australia, which has the highest incidence rates in the world. All 61 cases of melanoma in children less than 15 years notified to the Queensland Cancer Registry 1987-1994 were eligible to participate in a population-based, case-control study. Data were collected through structured, face-to-face interviews with parents and skin examinations of the 52 participating cases and 156 age- and sex-matched controls. The strongest determinants of melanoma risk found among Queensland children were constitutional factors, including the presence of more than 10 naevi greater than 5 mm in diameter (RR 9.9, 95% CI 2.5-38.9), heavy facial freckling (RR 6.4, 95% CI 1.9-21.6), an inability to tan on exposure to the sun (RR 8.8, 95% CI 2.1-36.2) and a family history of melanoma (RR 4.2, 95% CI 1.9-9.3). These factors remained significantly associated with melanoma after adjusting for other risk factors. No measures of acute or chronic exposure to solar UV radiation were associated with childhood melanoma in our study. Established risk factors, including giant congenital naevi and xeroderma pigmentosum, were not present among any of the children in the study. Melanoma in childhood appears to have similar epidemiologic characteristics to the adult form of the disease, being associated with a cluster of phenotypic attributes indicating cutaneous sensitivity to the effects of sun exposure. Our findings support the contention that childhood melanoma occurs in susceptible individuals with a low threshold for pigment cell tumorigenesis. From a public-health perspective, children at elevated risk for melanoma can be identified on the basis of phenotype and family history.
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PMID:Risk factors for childhood melanoma in Queensland, Australia. 898 86

This study was performed to analyse the behaviour, risk factors, prognosis and evolution of cutaneous melanoma in childhood and adolescence treated in a single institution. A retrospective study was performed between 1980 and 2000 of patients aged 18 years or younger followed at the Hospital do Cancer de Sao Paulo, Brazil. Data included demographic status, risk factors, clinical and histopathological characteristics of the primary and metastatic lesions, stage and follow-up. Seventeen female (53.1%) and 15 male (46.9%) patients were studied. Twelve patients (37.5%) were aged 12 years or younger. The trunk was the most common location (14 patients; 43.8%). Five patients (15.6%) had giant congenital melanocytic naevus, three (9.4%) had xeroderma pigmentosum and one (3%) had dysplastic melanocytic naevus. Nodular melanoma was the most frequent histological type and 43.8% had a thickness of more than 4 mm. Five of the 32 patients (15.6%) were lost to follow-up and 15 (46.9%) were alive at the last year's follow-up, 11 (34.4%) without disease and four (12.5%) with active disease. The 5-year overall survival was 64.34%. An overall survival of 11.71% was found in patients with visceral metastasis with or without cutaneous and/or lymph node involvement, whereas the corresponding value was 90.48% (P value=0.0002) in patients with only cutaneous and/or lymph node metastasis. Cutaneous melanomas are uncommon in the young and are seldom diagnosed in the early stages, perhaps due to a reluctance to accept this diagnosis in this age group. Prevention and early stage diagnosis depend upon the recognition that this disease is present in the young.
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PMID:Cutaneous melanoma in childhood and adolescence: retrospective study of 32 patients. 1557 19

Individuals with the rare DNA repair deficiency syndrome xeroderma pigmentosum (XP) are sensitive to the sun and exhibit a 1000-fold increased risk for developing skin cancers, including cutaneous melanoma. Inherited polymorphisms of XP genes may contribute to subtle variations in DNA repair capacity and genetic susceptibility to melanoma. We investigated the role of three polymorphic alleles of the DNA repair gene XPC in a hospital-based case-control study of 294 Caucasian patients from Germany who had cutaneous melanoma and 375 healthy cancer-free sex-matched Caucasian control subjects from the same area. We confirmed that the XPC intron 9 PAT+, intron 11 -6A, and the exon 15 2920C polymorphisms are in a linkage disequilibrium. Only 1.6% of the 669 donors genotyped were discordant for these three polymorphisms. The allele frequencies (cases: controls) were for intron 9 PAT+ 41.7%:36.9%, for intron 11 -6A 41.8%:37.0% and for exon 15 2920C 41.3%:37.3%. Using multivariate logistic regression analyses to control for age, skin type and number of nevi, the three polymorphisms were significantly associated with increased risks of melanoma: OR 1.87 (95% CI: 1.10-3.19; P = 0.022), OR 1.83 (95% CI: 1.07-3.11; P = 0.026), and OR 1.82 (95% CI: 1.07-3.08; P = 0.026), respectively. Exploratory multivariate analyses of distinct subgroups revealed that these polymorphisms were associated with increased risks for the development of multiple primary melanomas (n = 28). The results of our case-control study support the hypothesis that the intron 9 PAT+, intron 11 -6A and exon 15 2920C haplotype may contribute to the risk of developing cutaneous melanoma by increasing the rate of an alternatively spliced XPC mRNA isoform that skips exon 12 and leads to reduced DNA repair. Our results should be validated in independent samples in order to guard against false positive findings.
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PMID:Assessment of 3 xeroderma pigmentosum group C gene polymorphisms and risk of cutaneous melanoma: a case-control study. 1573 Nov 65

Nucleotide excision repair (NER) is the most versatile and best studied DNA repair system in humans. NER can repair a variety of bulky DNA damages including UV-light induced DNA photoproducts. NER consists of a multistep process in which the DNA lesion is recognized and demarcated by DNA unwinding. Then, an approximately 28 bp DNA damage containing oligonucleotide is excised followed by gap filling using the undamaged DNA strand as a template. The consequences of defective NER are demonstrated by three rare autosomal-recessive NER-defective syndromes: xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD). XP patients show severe sun sensitivity, freckling in sun exposed skin, and develop skin cancers already during childhood. CS patients exhibit sun sensitivity, severe neurologic abnormalities, and cachectic dwarfism. Clinical symptoms of TTD patients include sun sensitivity, freckling in sun exposed skin areas, and brittle sulfur-deficient hair. In contrast to XP patients, CS and TTD patients are not skin cancer prone. Studying these syndromes can increase the knowledge of skin cancer development including cutaneous melanoma as well as basal and squamous cell carcinoma in general that may lead to new preventional and therapeutic anticancer strategies in the normal population.
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PMID:Nucleotide excision repair and cancer. 1685 87

To look for a direct role of ultraviolet radiation (UV) exposure in cutaneous melanoma induction, we studied xeroderma pigmentosum (XP) patients who have defective DNA repair resulting in a 1000-fold increase in melanoma risk. These XP melanomas have the same anatomic distribution as melanomas in the general population. We analyzed laser capture microdissection samples of skin melanomas from XP patients studied at the National Institutes of Health. The tumor suppressor gene PTEN was sequenced and analyzed for UV-induced mutations. Samples from 59 melanomas (47 melanomas in situ and 12 invasive melanomas) from 8 XP patients showed mutations in the PTEN tumor suppressor gene in 56% of the melanomas. Further, 91% of the melanomas with mutations had 1 to 4 UV type base substitution mutations (occurring at adjacent pyrimidines) (P < 0.0001 compared to random mutations). We found a high frequency of amino-acid-altering mutations in the melanomas and demonstrated that these mutations impaired PTEN function; UV damage plays a direct role in induction of mutations and in inactivation of the PTEN gene in XP melanomas including in situ, the earliest stage of melanoma. This gene is known to be a key regulator of carcinogenesis and therefore these data provide solid mechanistic support for UV protection for prevention of melanoma.
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PMID:Evidence of ultraviolet type mutations in xeroderma pigmentosum melanomas. 1932 85


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