DNA repair capacities of cutaneous fibroblasts: effect of sun exposure, age and smoking on response to an acute oxidative stress.

Background: Sun irradiation causes skin ageing and cancer through the accumulation of damage to cell components. Intrinsic ageing is also associated with accumulation of oxidized macromolecules.

Objectives: In this study we investigated the effects of sun exposure on response to an acute in vitro oxidative stress (H(2)O(2)) using normal human fibroblasts prepared from biopsies from 10 volunteers taken from sun-protected and sun-exposed sites.

Predominance of the 1,N2-propano 2'-deoxyguanosine adduct among 4-hydroxy-2-nonenal-induced DNA lesions.

4-Hydroxy-2-nonenal (HNE), one of the main aldehydic compounds released during lipid peroxidation, has been proposed to react with DNA bases in cells. Several classes of DNA lesions involving addition of either HNE or its 2,3-epoxide (epox-HNE) have been identified. In the present work, HPLC associated with tandem mass spectrometry was used to determine the pattern of HNE-induced DNA lesions.

Formation of modified DNA bases in cells exposed either to gamma radiation or to high-LET particles.

The aim of the present study was to measure the formation of eight base modifications in the DNA of cells exposed to either low-LET ((60)Co gamma rays) or high-LET ((12)C(6+) particles) radiation. For this purpose, a recently optimized HPLC-MS/MS method was used subsequent to DNA extraction and hydrolysis. The background level of the measured modified bases and nucleosides was shown to vary between 0.