ABSTRACT
The important role for oxidative damage in the UVA effect implies that pairs of oxidative deoxyribonucleic acid (DNA) single stranded damage form the critical lesion and not pyrimidine dimers. Ultraviolet (UV) light falls between visible light and X-rays and gamma rays on the spectrum of electromagnetic radiation and is strongly associated with skin cancer. The UV range is usually divided up into UVA, UVB and UVC. The review by Cadet et al. reveals a wide range of photoproducts induced in the cell by UVA exposure and also reveals the importance of the oxidative damage, such as DNA single strand breaks and 8-oxo-7,8-dihydroguanine DNA base damage for the biological effect. Some good experimental data supporting the ‘paired dimer’ lesion as critical for UV cellular effects are to be found in the work of Wade and Lohman. They measured UV-induced cell survival in chicken embryo cells before and after photo-reactivation and correlated survival with number of endonuclease-sensitive sites, which are presumed to be dimers.
