DNA polymerase β imbalance increases apoptosis and mutagenesis induced by oxidative stress

Oxidative stress has been proposed to be one of the major causes leading to the accumulation of mutation that is associated with the initiation and progression of cancers. Elevated expression of DNA polymerase β, an event found in many human tumors, has been shown to generate a mutator phenotype. Here, we demonstrated that overexpression of DNA polymerase β strengthens the mutagenicity of oxidative damages, concomitantly with a higher cellular sensitivity and increased apoptosis. Deregulated expression of DNA polymerase β could represent a predisposition factor for mutagenic effects of oxidative stress and thus have implication in the generation and/or evolution of cancer.