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)

We report the case of a conjunctival tumor in a 9-year-old patient, suffering from Xeroderma Pigmentosum. Our patient presented a raspberry-colored conjunctival tumor. The tumor was resecked without any additional treatment. The histological study revealed squamous cell carcinoma. A suspicion of relapse appeared two months later of the same location and a new resection was performed. The initial checkup of this tumor was negative. In this disease, ocular localizations are frequent. The conjunctiva, the cornea, the eyelids and, into a lesser extent, the orbit can be involved. Basal cell carcinoma and squamous cell carcinoma are the most frequent tumors observed in Xeroderma Pigmentosum. Their treatment is mainly surgical.
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PMID:[Conjunctival epithelial carcinoma in a 9-year-old child with xeroderma pigmentosum. Case report]. 1146 62

Repair of UV induced DNA damage is of key importance to UV-induced skin carcinogenesis. Specific signal transduction pathways that regulate cell cycling, differentiation and apoptosis are found to be corrupted in skin cancers, e.g., the epidermal growth-stimulating Hedgehog pathway in basal cell carcinomas (BCCs). Mutations in genes coding for proteins in these pathways lead to persistent disturbances that are passed along to daughter cells, e.g., mutations in the gene for the Patched (PTCH) protein in the Hedgehog pathway. Thus far only the point mutations in the P53 gene from squamous cell carcinomas and BCCs, and in PTCH gene from BCC of xeroderma pigmentosum (XP) patients appear to be unambiguously attributable to solar UV radiation. Solar UVB radiation is most effective in causing these point mutations. Other forms of UV-induced genetic changes (e.g., deletions) may, however, contribute to skin carcinogenesis with different wavelength dependencies.
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PMID:UV-induced DNA damage, repair, mutations and oncogenic pathways in skin cancer. 1168 48

Sebaceous naevi are uncommon congenital skin lesions with a well-recognised potential for neoplastic change. They should be considered premalignant lesions as malignant degeneration, most commonly basal cell carcinoma and squamous cell carcinoma, occurs with a lifetime risk of between 5% and 22%. This incidence is equal to that of actinic keratosis and exceeds that of oral leukoplakia. Such change, however, is rare before puberty. Basal cell carcinoma may develop in children with naevoid basal cell carcinoma syndrome, xeroderma pigmentosum and rarely de novo but sebaceous naevus is the only solitary lesion in childhood associated with the development of basal cell carcinoma. We present two cases of malignant transformation in a congenital sebaceous naevus occurring in childhood and review the literature and discuss the evidence upon which to base management guidelines.
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PMID:Malignant transformation in congenital sebaceous naevi in childhood. 1169

Skin cancer is unique among human cancers in its etiology, accessibility and the volume of detailed knowledge now assembled concerning its molecular mechanisms of origin. The major carcinogenic agent for most skin cancers is well established as solar ultraviolet light. This is absorbed in DNA with the formation of UV-specific dipyrimidine photoproducts. These can be repaired by nucleotide excision repair or replicated by low fidelity class Y polymerases. Insufficient repair followed by errors in replication produce characteristic mutations in dipyrimidine sequences that may represent initiation events in carcinogenesis. Chronic exposure to UVB results in disruption of the epithelial structure and expansion of pre-malignant clones which undergo further genomic changes leading to full malignancy. Genetic diseases in DNA repair, xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy, show varied elevated symptoms of sun sensitivity involving skin cancers and other symptoms including neurological degeneration and developmental delays. In humans, only xeroderma pigmentosum shows high levels of cancer, but mouse strains, with any of the genes corresponding to these diseases knocked-out, show elevated skin carcinogenesis. The three major skin cancers exhibit characteristic molecular changes defined by certain genes and associated pathways. Squamous cell carcinoma involves mutations in the p53 gene; basal cell carcinoma involves mutations in the PATCHED gene, and melanoma in the p16 gene. The subsequent development of malignant tumors involves many additional genomic changes that have yet to be fully cataloged.
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PMID:UV damage, DNA repair and skin carcinogenesis. 1189 51

Basal cell carcinoma (BCC) of the skin is the most common type of cancer in humans. Like squamous cell carcinomas, they are also believed to be ultraviolet (UV)-induced, but several data suggest that some differences might exist in the mechanisms of their UV induction. The originating cells may arise from interfollicular basal cells, hair follicles or sebaceous glands, thus from a deeper zone than the SCC ones, which probably means exposure to different doses or wavelengths of UV. The p53 gene and the patched gene (PTCH) are major targets of UV for BCC induction. Mutations in p53 are present in about 56% of human BCC, even small early lesions. The "UV signature" is observed in 65% of them. Mutations in the PTCH play also a major role in BCC development, being responsible for hereditary BCCs in Gorlin's syndrome, sporadic BCC, and BCCs isolated from xeroderma pigmentosum, although with a lower incidence of "UV signature". Smoothened-activating mutations and PTCH2 mutations are also involved in BCC formation. Transgenic mice overexpressing Smoothened or Sonic hedgehog in the skin spontaneously produce skin lesions resembling human BCCs, but contrary to findings in the hairless albino mouse and with SCC, no data on experimental UV induction of BCCs are available.
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PMID:Carcinogenesis of basal cell carcinomas: genetics and molecular mechanisms. 1196 27

Xeroderma pigmentosum is an inheritable autosomal recessive DNA repair deficient syndrome characterized by a high predisposition to skin cancers. An elevated proportion of tumors from xeroderma pigmentosum patients harbor ultraviolet-induced mutations (CC:GG > TT:AA tandem transitions) of the p53 and/or the INK4a-ARF genes. Here, we report the clinical and molecular features of a 12 y old xeroderma pigmentosum patient who, in addition to severe cutaneous clinical symptoms, also had three unusual tumors, a mediastinal lymphoblastic lymphoma, an atypical fibroxanthoma, and an epithelioid hemangioma. Single strand conformation polymorphism and sequencing analysis of the p53 and INK4a-ARF genes were carried out in DNA from normal skin and different tumors (four actinic keratosis, two microinvasive squamous cell carcinomas, one basal cell carcinoma, and one atypical fibroxanthoma) from the patient. After characterization of the xeroderma pigmentosum C complementation group, we found unexpectedly that this patient also carried a germline mutation of the INK4a-ARF locus affecting the p16INK4A reading frame. Three different somatic mutations that all harbor the signature of ultraviolet light (two of p16INK4A and one of p53) were also detected in the basal cell carcinoma. We hypothesize that the germline mutation of p16INK4A, in association with the nucleotide excision repair defect, could explain the patient's unusual phenotype. Furthermore, this study confirms that concomitant somatic mutations of INK4a-ARF and p53 occur in some xeroderma pigmentosum associated tumors, and seem to accumulate during tumor progression rather than the initiation step.
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PMID:Germline and somatic mutations of the INK4a-ARF gene in a xeroderma pigmentosum group C patient. 1248 39

The Sonic hedgehog (SHH) pathway is implicated in the etiology of the most common human cancer in Caucasians, the basal cell carcinoma (BCC). Mutations in the receptor of SHH, the patched gene, have been characterized in sporadic BCCs as well as those from patients with the rare genetic syndromes nevoid BCC and xeroderma pigmentosum (XP). To elucidate the role of UV in the deregulation of the SHH pathway, we analyzed for alterations of smoothened, a transmembrane signaling component regulated by patched, in BCCs and squamous cell carcinomas from UV hypersensitive XP patients. We find UV-specific smoothened mutations in 30% of XP BCCs, three times higher than those in sporadic Caucasian BCCs, confirming the high rate of UV-induced mutations in DNA repair-deficient XP patients. No alteration was found in XP squamous cell carcinomas, indicating the involvement of smoothened specifically in the development of BCC.
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PMID:Significantly high levels of ultraviolet-specific mutations in the smoothened gene in basal cell carcinomas from DNA repair-deficient xeroderma pigmentosum patients. 1249 55

The p53 gene (TP53) is mutated in numerous human cancers. We have used it as a molecular target to characterize the induction of mutations in human skin cancers. About 50% of all skin cancers in normal individuals exhibit p53 mutations. This frequency rises to 90% in skin cancers of patients with the DNA-repair deficiency known as xeroderma pigmentosum (XP). These mutations are characterized by a specific signature, attributed to the ultraviolet uvB part of the solar spectrum. In this review, we will describe different p53 mutation spectra, in relation to the various histopathological types of skin cancers such as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and malignant melanoma as well as to the DNA repair efficiency of the patients. In particular, different mutational hot spots are found among the various spectra. We have tried to elucidate them in terms of induced DNA lesion hot spots, as well as speed of local nucleotide excision repair (NER) or sequence effects. The molecular analysis of these mutagenic characteristics should help in the understanding of the origin of human skin cancers in the general population.
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PMID:TP53 mutations in human skin cancers. 1261 7

Xeroderma pigmentosum (XP) is a rare autosomal recessive photosensitive disorder, which results in multiple face, neck and head basal cell carcinomas (BCCs), squamous cell carcinomas and melanomas. A 15-year-old boy with XP presented with multiple facial BCCs previously treated by surgical excision. Standard BCC treatments such as surgery are not ideal for patients with several facial BCCs because of the risk of scarring, and the patient refused further surgery. As an alternative, three times weekly application of imiquimod 5% cream in combination with oral acitretin (20 mg daily) was prescribed for 4-6 weeks. No adverse events were reported during treatment and all tumours had resolved at the 6-month follow up visit, highlighting the therapeutic potential of imiquimod 5% cream.
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PMID:The treatment of basal cell carcinomas in a patient with xeroderma pigmentosum with a combination of imiquimod 5% cream and oral acitretin. 1461 11

The malignant tumours of the lip account for nearly 1-2% of the cervicofacial neoplasms. These lesions are frequently spinous cell carcinomas and basal cell carcinomas (25% of all oral cancers). The spinous cell carcinoma is mainly located in the lower lip, the basal cell carcinoma is more common in the upper lip. The incidence of lip cancer in males is much high than in females. The etiopathogenesis of these lesions is connected with exposure to sun, smoking, genetics predisposition (mutation of the p53 suppressor factor) and with the evolution of precancerous lesions (radiodermatitis, chronic cheilitis, xeroderma pigmentosum). Some Authors emphasized the viral etiopathogenesis: HPV16, HPV24, HSV1, HSV2. The treatment of lip carcinoma is surgical: excision and reconstruction. The numerous reconstructive techniques are mostly the cutaneous local sliding flaps and the rotation flaps. The lip reconstruction require a remarkable diligence for preserve, as much possible, the shape and functions of lip. The Authors report their experience about the surgical treatment of 19 patients with lip carcinoma (16 spinous cell carcinomas, 3 basal cell carcinomas) and describe the main surgical reconstructive techniques to preserve the feeding, phonation and mimic expression.
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PMID:[Surgical treatment of malignant lip tumors. Personal experience]. 1472 93


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