Wang Jing, He Linfeng, Fan Dunhuang, Ding Defang, Wang Xufei, Gao Yun, Zhang Xuxia, Li Qiang, Chen Honghong
Department of Radiation Biology, Institute of Radiation Medicine, Fudan University, 200032 Shanghai, China.
Department of Radiology, Ningbo Medical Center, Lihuili Eastern Hospital, Ningbo 315100, Zhejiang, China.
Sci Rep. 2016 Jul 22;6:30018. doi: 10.1038/srep30018.
The biodosimetric information is critical for assessment of cancer risk in populations exposed to high radon. However, no tools are available for biological dose estimation following radon exposure. Here, we established a γ-H2AX foci-based assay to determine biological dose to red bone marrow (RBM) in radon-inhaled rats. After 1-3 h of in vitro radon exposure, a specific pattern of γ-H2AX foci, linear tracks with individual p-ATM and p-DNA-PKcs foci, was observed, and the yield of γ-H2AX foci and its linear tracks displayed a linear dose-response manner in both rat peripheral blood lymphocytes (PBLs) and bone-marrow lymphocytes (BMLs). When the cumulative doses of radon inhaled by rats reached 14, 30 and 60 working level months (WLM), the yields of three types of foci markedly increased in both PBLs and BMLs, and γ-H2AX foci-based dose estimates to RBM were 0.97, 2.06 and 3.94 mGy, respectively. Notably, BMLs displayed a more profound increase of three types of foci than PBLs, and the absorbed dose ratio between BMLs and PBLs was similar between rats exposed to 30 and 60 WLM of radon. Taken together, γ-H2AX foci quantitation in PBLs is able to estimate RBM-absorbed doses with the dose-response curve of γ-H2AX foci after in vitro radon exposure and the ratio of RBM- to PBL-absorbed doses in rats following radon exposure.
生物剂量测定信息对于评估暴露于高氡环境中的人群患癌风险至关重要。然而，目前尚无用于氡暴露后生物剂量估算的工具。在此，我们建立了一种基于γ-H2AX焦点的检测方法，以确定吸入氡的大鼠红骨髓（RBM）的生物剂量。在体外氡暴露1-3小时后，观察到γ-H2AX焦点的特定模式，即带有单个p-ATM和p-DNA-PKcs焦点的线性轨迹，并且γ-H2AX焦点及其线性轨迹的产量在大鼠外周血淋巴细胞（PBLs）和骨髓淋巴细胞（BMLs）中均呈现线性剂量反应方式。当大鼠吸入氡的累积剂量达到14、30和60工作水平月（WLM）时，PBLs和BMLs中三种类型焦点的产量均显著增加，基于γ-H2AX焦点对RBM的剂量估计分别为0.97、2.06和3.94 mGy。值得注意的是，BMLs中三种类型焦点的增加比PBLs更为显著，并且在暴露于30和60 WLM氡的大鼠中，BMLs与PBLs之间的吸收剂量比相似。综上所述，通过体外氡暴露后γ-H2AX焦点的剂量反应曲线以及氡暴露后大鼠中RBM与PBL吸收剂量的比值，PBLs中γ-H2AX焦点定量能够估算RBM吸收剂量。
