1 Introduction Many of the cellular effects of reactive oxygen species (ROS) are due to oxidation of the base composition of DNA. Among the DNA bases, the most susceptible base to oxidation is guanine (Gua). The generated 8-oxo-7,8-dihydroguanine (8-oxoGua) is a marker of oxidative stress intensity (1). 8-oxoGua is repaired through the evolutionally conserved base excision repair (BER) pathway (2), which is primarily initiated by 8-oxoguanine DNA glycosylase/lyase 1 (OGG1) (3).
