Use of human lymphocyte G0 PCCs to detect intra- and inter-chromosomal aberrations for early radiation biodosimetry and retrospective assessment of radiation-induced effects

A sensitive biodosimetry tool is required for rapid individualized dose estimation and risk assessment in the case of radiological or nuclear mass casualty scenarios to prioritize exposed humans for immediate medical countermeasures to reduce radiation related injuries or morbidity risks. Unlike the conventional Dicentric Chromosome Assay (DCA), which takes about 3–4 days for radiation dose estimation, cell fusion mediated Premature Chromosome Condensation (PCC) technique in G0 lymphocytes can be rapidly performed for radiation dose assessment within 6–8 hrs of sample receipt by alleviating the need for ex vivo lymphocyte proliferation for 48 hrs. Despite this advantage, the PCC technique has not yet been fully exploited for radiation biodosimetry. Realizing the advantage of G0 PCC technique that can be instantaneously applied to unstimulated lymphocytes, we evaluated the utility of G0 PCC technique in detecting ionizing radiation (IR) induced stable and unstable chromosomal aberrations for biodosimetry purposes. Our study demonstrates that PCC coupled with mFISH and mBAND techniques can efficiently detect both numerical and structural chromosome aberrations at the intra- and inter-chromosomal levels in unstimulated T- and B-lymphocytes. Collectively, we demonstrate that the G0 PCC technique has the potential for development as a biodosimetry tool for detecting unstable chromosome aberrations (chromosome fragments and dicentric chromosomes) for early radiation dose estimation and stable chromosome exchange events (translocations) for retrospective monitoring of individualized health risks in unstimulated lymphocytes.

针对放射或核大规模伤亡场景，亟需研发灵敏的生物剂量测定工具，以实现快速个体化剂量估算与风险评估，从而对受照人员进行救治优先级排序，及时采取医学干预措施以降低辐射相关损伤及发病风险。与传统双着丝粒染色体分析法（Dicentric Chromosome Assay, DCA）需约3~4天完成辐射剂量估算不同，G0期淋巴细胞的细胞融合介导早熟染色体凝集（Premature Chromosome Condensation, PCC）技术无需将淋巴细胞体外培养48小时完成增殖步骤，可在样本接收后6~8小时内快速开展辐射剂量评估。尽管具备该优势，PCC技术尚未在辐射生物剂量测定中得到充分应用。鉴于G0 PCC技术可直接应用于未受刺激淋巴细胞的特性，本研究评估了该技术在生物剂量测定中用于检测电离辐射（Ionizing Radiation, IR）诱导的稳定与不稳定染色体畸变的应用价值。本研究证实，将PCC技术与mFISH及mBAND技术联用，可在未受刺激的T、B淋巴细胞的染色体内及染色体间水平，高效检出数量型与结构型染色体畸变。综上，本研究表明G0 PCC技术具备开发为生物剂量测定工具的潜力：既可用于检测不稳定染色体畸变（染色体片段与双着丝粒染色体）以实现早期辐射剂量估算，又可检出稳定染色体交换事件（染色体易位）以对未受刺激淋巴细胞的个体健康风险开展回顾性监测。