• Korean Journal of Head & Neck Oncology
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• v.36 no.1
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• pp.39-44
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• 2020

Xeroderma pigmentosum is a rare autosomal recessive disease, related to defects in DNA repair mechanism. It presents skin lesions on sun-exposed areas, leading to various skin cancer. Skin lesions can be treated with cryotherapy, skin resurfacing, 5-FU, Imiquimod, topical T4 endonuclease V, radiotherapy and genetic therapy, but invasive skin cancer should be treated by a surgery. We report a 12-year-old female xeroderma pigmentosum patient with recurrent basal cell carcinoma successfully treated by skin grafting. In that there is no cure for this disease, prevention and patient education is most important.

• Journal of Photoscience
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• v.9 no.2
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• pp.479-481
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• 2002

UV-induced DNA damage causes cell killing and mutations leading to carcinogenesis. In normal human cells, UV damage such as cyclobutane pyrimidine dimers (CPDs) and primidine-prymidone (6-4) photoproducts are mainly repaired by nucleotide excision repair mechanism. The molecular processes have been well characterized recently. To know the influence of mitochondrial genome on the nucleotide excision repair mechanism against CPDs, we comparatively examined the production of CPDs by UVC irradiation and their repair kinetics in human cells completely lacking mitochondrial DNA (mtDNA) and the parental HeLa S cells. Whole DNA extracted from the cells exposed to UVC was treated with T4-endonuclease V to break the phosphodiester bond adjacent to CPDs. The DNA was electrophoresed in a denaturing agarose gel, which was visualized by ethidium bromide staining. The relative amount of CPDs was determined by image analysis using NIH Image software. MtDNA- less (rho-O) cells were apparently more sensitive to UVC than HeLa S cells, while the level of induction of CPDs in rho-O and HeLa cells was comparable. The repair of CPDs was less efficient in rho-O cells compared with HeLa cells. The residual amount of CPDs after 24-h repair was larger in rho-O cells than in HeLa cells where more than 90 % of CPDs were repaired by then. The non-repaired CPDs would lead to apoptosis in rho-O cells. These results suggest that mitochondrial genome may contribute to some ATP-dependent steps in nucletide excision repair by supplying sufficient ATP which is generated through a respiratory chain in mitochondria.