Assessment of biological effect of low-dose radiation by phosphorylated H2AX in vivo

辐射诱导的dna双链断裂（DSB）是导致癌症的基因组不稳定的主要初始原因之一。真核细胞中DNA DSB的形成通常伴随着在DSB位点两侧染色质中形成数百个磷酸化的H2AX （γ -H2AX）分子。针对γ - h2ax的抗体可以使DSB位点的“焦点”可视化。由于已经证明γ - h2ax焦点的数量与DNA DSB的数量直接相关，因此检测γ - h2ax是监测DNA DSB水平的有吸引力的候选物。在这里，为了评估事故后辐射暴露的生物效应，我们对福岛疏散区牛淋巴细胞中γ - h2ax焦点作为DNA DSB的制造者进行了定量。虽然大多数淋巴细胞γ - h2ax灶呈阴性，但免疫染色数据清楚地显示福岛疏散区γ - h2ax灶阳性细胞数量增加。

Radiation induced-DNA double strand break (DSB) is one major initial cause of genomic instability leading to cancer. The creation of a DNA DSB in eukaryotic cells is generally accompanied by the formation of hundreds of phosphorylated H2AX (gamma-H2AX) molecules in the chromatin flanking the DSB site. Antibodies to gamma-H2AX allow the visualization of a "focus" at the DSB site. Since it has been demonstrated that the numbers of gamma-H2AX foci correlate directly to the numbers of DNA DSB, the detection of gamma-H2AX is an attractive candidate for monitoring DNA DSB levels. Here, to assess biological effect by radiation exposure after the accident, we performed quantitation of gamma-H2AX foci as a maker of DNA DSB in bovine lymphocytes from Fukushima evacuated area. Although majority of lymphocytes are negative of gamma-H2AX foci, immunostaining data clearly showed an increase of population of gamma-H2AX foci positive cells from Fukushima evacuated area.