Cellular DNA and other biomolecules within irradiated tissue

Cellular DNA and other biomolecules within irradiated tissue represent the fundamental substrates for the biological effects of ionizing radiation. The primary mechanism of therapeutic radiation involves the induction of complex DNA damage, particularly double-strand breaks, which are the most lethal form of injury to cancer cells (Hall & Giaccia, 2018). This damage occurs either through direct ionization of the DNA phosphate backbone or indirectly through the radiolysis of water, which generates highly reactive hydroxyl radicals that oxidize various cellular components including lipids and proteins (Desouky et al., 2015). In clinical practice, this target is modulated by radiosensitizers like cisplatin or misonidazole to increase tumor kill, or by radioprotectors like amifostine to preserve healthy tissue function (Stone et al., 2003). Understanding the interaction between radiation and these biomolecules is crucial for optimizing therapeutic ratios in oncology and managing accidental radiation exposure (StatPearls, 2023). Monitoring the efficacy of these interactions often involves measuring biomarkers of DNA damage, such as the phosphorylation of histone H2AX (gamma-H2AX) (Kuo & Yang, 2008).

Other names

Genomic DNACellular macromoleculesRadiation targetsRadiobiological targets

Induction of DNA double-strand breaks and oxidative damage via direct ionization or water radiolysis-derived free radicals (PubMed, 2015).