Cellular DNA and biomolecules in proximity to beta-minus emissions (DNA/Biomolecules)

Cellular DNA and surrounding biomolecules represent the critical biological targets for therapeutic beta-minus (β⁻) radiation. Beta-minus decay involves the emission of electrons from the nucleus of a radionuclide, which then travel through tissue and lose energy via interactions with atoms and molecules (National Cancer Institute, 2023). The primary therapeutic effect is achieved through the induction of DNA damage, specifically double-strand breaks (DSBs), which are difficult for the cell to repair and lead to cell death via apoptosis or necrosis (Journal of Nuclear Medicine, 2018). This damage occurs through two pathways: direct ionization of the DNA structure and indirect action via the radiolysis of water, which generates highly reactive hydroxyl radicals (IAEA, 2021). In targeted radionuclide therapy, such as those using Lutetium-177 or Yttrium-90, the radiation is delivered to specific sites like tumors, where the 'crossfire effect' allows the beta particles to kill both the targeted cell and adjacent malignant cells within their range (Nature Reviews Drug Discovery, 2020). However, this same mechanism poses risks to healthy tissues in proximity, such as the bone marrow or kidneys, depending on the biodistribution of the radiopharmaceutical.

Other names

Genomic DNACellular macromoleculesIonizing radiation targetsRadiotherapeutic targetsCritical biomolecular targets

Beta-minus particles (electrons) emitted from radionuclides travel through cellular environments, causing direct ionization of the DNA phosphate backbone and indirect damage through the radiolysis of water molecules. This process generates reactive oxygen species (ROS), such as hydroxyl radicals, which induce single- and double-strand DNA breaks (PubMed: 29339471). The accumulation of these lesions, particularly double-strand breaks, triggers DNA damage response pathways, leading to cell cycle arrest and programmed cell death (apoptosis) or mitotic catastrophe (StatPearls: Radiation Physics, 2023).