DNA double-strand breaks (DSB) are created by ionizing radiation, an important environmental genotoxic agent. DSB are repaired by two mechanisms associated with recombination. In eukaryotic cells homologous recombination depends on genes belonging to the RAD52 epistatic group. Alternative pathway, DNA end--joining in non-homologous recombination involves DNA-dependent protein kinase (DNA-PK).
P. Wid?ak, Centrum Radiologii Doswiadczalnej i Klinicznej, Centrum Onkologii ? Instytut im. M.Sklodowskiej-Curie, Wybrzeze Armii Krajowej 15, 44-100 Gliwice, Poland