Analysis of the cytoplasmic radiation responses by using X-ray microbeam irradiation techniques

微束细胞照射系统是阐明生物对低剂量辐射反应机制的有力工具。在这项研究中，我们用新的X射线微束照射技术分析了细胞内照射区域与细胞反应之间的关系。我们的结果清楚地表明，DNA修复反应的信号过程是通过细胞质辐射反应来改变的。此外，我们发现辐射诱导的旁观者反应可以增强旁观者细胞群体中遗传不稳定细胞的选择性细胞杀伤，这种选择性细胞死亡可能作为一种保护机制，与非致命性和潜在致癌损害的增加竞争，例如突变。胞核和胞浆之间的细胞内通讯在决定低剂量区细胞死亡方面发挥着重要作用。我们的发现可能为评估低剂量辐射的风险提供重要信息。

Microbeam cell irradiation system is a powerful tool in the elucidation of the mechanisms underlying biological responses to low-dose radiations. In this study, we analyzed the relationship between irradiation domain in the cells and the cellular responses with new X-ray microbeam irradiation techniques. Our results clearly demonstrated that the signaling process of DNA repair responses were modified via cytoplasmic radiation responses. Furthermore, we found that radiation-induced bystander responses can enhance selective cell killing of genetically unstable cells in the bystander cell population and that this selective cell death may act as a protective mechanism that competes with increases in non-lethal and potentially carcinogenic damages, e.g. mutations. Intracellular communication between the nucleus and cytoplasm plays an important role in determining cell death in the low-dose region. Our findings may provide important information to evaluate the risk of low doses of radiation.