This quality assurance programme has now been extended to include laboratories in the USA and Japan. This research has examined background levels and types of damage in normal individuals and its amelioration by antioxidant vitamins. These studies are the first of many on both healthy individuals and patients with inflammatory autoimmune disease as part of our MAFF funded program of research on novel techniques for monitoring oxidative damage. This work culminated in 1998 with the publication of an article in Nature which aroused intense media and scientific interest, forcing a re-examination of the mechanisms of antioxidant vitamin function which we are pursuing vigourously. These studies are set to continue with further method validation, establishment of new assay procedures, multi-lesion analysis and new antioxidant supplementation studies.
Many carcinogens act directly on DNA causing base damage and subsequent mutation.
We have confirmed that this lesion is a specific marker of oxidative DNA damage and is produced in cells undergoing oxidative stress. We have established using these methods that 8-oxodG is produced by UVC, UVB and UVA radiation in naked DNA and DNA in cells stressed in vitro . In combination with chromatographic and immunoassay of 8-oxodG, these UV specific assays are allowing us to define the mechanisms for the genotoxic action of different wavelengths of UV light to which humans are exposed. These studies are being conducted for both human skin, in vivo , and cell culture models. The antibodies which we have developed have the capability of distinguishing oxidative DNA damage in skin sections and can detect background levels in skin cells from patients with basal cell carcinoma.