Technology
Decoding Chromosome Radiosensitivity in G0-Phase PBMCs: Genomic Determinants, Age, Sex effects, and Implications in Radiation Dose Assessment
Key Points
Low-dose ionizing radiation from natural and anthropogenic sources is typically not of significant concern under normal conditions. However, in case of radiological incidents, it becomes an important environmental hazard, raising concern for public health and necessitating reliable biological indicators of exposure. Chromosomal aberrations are most reliable markers of radiation exposure and are more or less universally assessed in metaphases.
Low-dose ionizing radiation from natural and anthropogenic sources is typically not of significant concern under normal conditions. However, in case of radiological incidents, it becomes an important environmental hazard, raising concern for public health and necessitating reliable biological indicators of exposure. Chromosomal aberrations are most reliable markers of radiation exposure and are more or less universally assessed in metaphases. Recently, rapid assessment of aberrations in G-phase lymphocytes using G-PCC-FISH has gained attention and is recognized as the most suitable method for dose assessment in cases of high-dose or partial-body exposure. This is first study in G0-phase at such scale to establish baseline and radiation induced aberrations in peripheral blood mononuclear cells (PBMCs) from 24 healthy human donors (12 males, 12 females, 21 to 60 Y). Using whole chromosome painting (WCP) of Chromosomes 1, 2 & 4 and scoring over 8500 cells post 0, 2, and 4 Gy gamma radiation exposure, we quantified 5586 aberrations and investigated their relationship with underlying genomic features. Our findings include: No significant effect of age or sex on chromosomal radiosensitivity, supporting the robustness of pooled biodosimetric calibration curves for dose assessment within the studied age range of 21 to 60 years. Chromosome-specific radiosensitivity does not appear to be solely dependent on chromosome size and shows a potential association with gene density and total transcript length. From public health point of view the present data provides reference values for interphase chromosomal damage as well as radiation induced reference values for two important dose points across age groups and sexes. This approach enhances emergency preparedness for radiological events by enabling rapid biodosimetry, especially critical when metaphase cells are unavailable as in cases of accidental high-dose or partial exposures.