DNA double-strand break induction via ionizing radiation

DNA double-strand break induction via ionizing radiation refers to the process by which ionizing radiation (such as X-rays, gamma rays, high-energy particles) causes the rupture of both strands of the DNA helix within cells. This event is considered among the most cytotoxic and mutagenic forms of DNA damage. Ionizing radiation can cause DSBs directly by breaking the phosphodiester DNA backbone or indirectly via the production of reactive oxygen species (ROS) that attack DNA. When not properly repaired, DSBs can lead to chromosomal aberrations, genomic instability, cell death (apoptosis, necrosis), and carcinogenesis. The detection and repair of these DNA lesions involve the activation of cellular DNA damage response (DDR) pathways, including phosphorylation of histone H2A.X (γH2A.X), recruitment of 53BP1, and engagement of the repair pathways homologous recombination (HR) and non-homologous end joining (NHEJ). These responses are central both to the effectiveness of radiotherapy in cancer and to the risk of unwanted tissue damage, secondary cancers, and long-term health consequences after radiation exposure.

Other names

DNA double-strand break (DSB) induction by ionizing radiationionizing radiation-induced DNA damageradiation-induced DSB