title: Individual photosensitivity of human skin and UVA-induced pyrimidine dimers in DNA.
abstract: Delineation of the DNA-damaging properties of UVA radiation is a major issue in understanding solar carcinogenesis. Emphasis was placed in this study on the formation of cyclobutane pyrimidine dimers (CPDs), which are now well established as the most frequent UVA-induced DNA lesions in human skin. The yield of CPDs was determined by a chromatographic assay following ex vivo UVA and UVB irradiation of biopsies taken from either phototype II or IV volunteers. A clear correlation was found between the frequency of UVB-induced CPDs and both the phototype and the minimum erythemal dose (MED). Similar results were obtained for the induction of CPDs upon exposure to UVA. Moreover, an excellent correlation was observed for each donor between the yield of DNA damage induced by either UVB or UVA. These observations show that the key parameters driving UVA-induced formation of CPDs are attenuation of radiation in the skin and the number of photons reaching skin cells rather than the cellular content in photosensitizers. In addition, the results show that both MED and phototype are good predictors of the vulnerability of DNA toward UVB and UVA in the skin. This result is of importance for the identification of individuals to be extensively protected.
authors: CEA, INAC, SCIB, UJF & CNRS, LCIB (UMR_E 3 CEA-UJF & FRE 3200), Laboratoire Lésions des Acides Nucléiques, Grenoble, France.
authors: Stéphane
authors: S
authors: Mouret
authors: Marie-Thérèse
authors: MT
authors: Leccia
authors: Jean-Luc
authors: JL
authors: Bourrain
authors: Thierry
authors: T
authors: Douki
authors: Jean-Claude
authors: JC
authors: Beani
mesh_terms: D000328:Adult; D004890:Erythema / Q000209:etiology; D006801:Humans; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D011740:Pyrimidine Dimers / Q000378:metabolism*; D011836:Radiation Tolerance; D012867:Skin / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000209:etiology*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D011740:Pyrimidine Dimers