Non-specific cellular DNA and biomolecules within radiation field

Non-specific cellular DNA and biomolecules within a radiation field serve as the fundamental substrates for the biological effects of ionizing radiation. The primary therapeutic objective in radiation oncology is the induction of complex DNA damage, particularly double-strand breaks, which are difficult for the cell to repair and lead to mitotic catastrophe or apoptosis (Hall & Giaccia, 2018). In addition to direct DNA ionization, radiation interacts with water molecules to produce reactive oxygen species, such as hydroxyl radicals, which non-specifically oxidize proteins, lipids, and other critical cellular components (Riley, 1994). This broad reactivity is exploited by radiopharmaceuticals and external beam radiation to destroy tumor cells, but it also poses a risk of toxicity to surrounding healthy tissues. Drugs interacting with this target include radiosensitizers that increase the yield of DNA damage and radioprotectors that scavenge free radicals to prevent biomolecular oxidation (Citrin et al., 2010). Monitoring efficacy often involves measuring biomarkers of DNA damage, such as the phosphorylation of histone H2AX (gamma-H2AX) (Kuo & Yang, 2008). Because the target is defined by the physical reach of the radiation field rather than a specific molecular binding site, therapeutic precision depends on the spatial delivery of the radiation source.

Other names

Cellular DNABiological macromoleculesGenomic DNACellular proteins and lipids

Induction of direct ionization and indirect oxidative damage via reactive oxygen species, resulting in DNA double-strand breaks and biomolecular degradation.