Institute for Integrated Cell-Material Sciences, Institute for Advanced Study, Kyoto University, Kyoto, Japan.
Institute for Integrated Cell-Material Sciences, Institute for Advanced Study, Kyoto University, Kyoto, Japan; Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
Enzymes. 2022;51:101-115. doi: 10.1016/bs.enz.2022.08.007. Epub 2022 Sep 27.
Irradiation of high Z elements such as iodine, gold, gadolinium with monochromatic X-rays causes photoelectric effects that include the release of Auger electrons. Decay of radioactive iodine such as I-123 and I-125 also results in multiple events and some involve the generation of Auger electrons. These electrons have low energy and travel only a short distance but have a strong effect on DNA damage including the generation of double-strand breaks. In this chapter, we focus on iodine and discuss various studies that used iodine-containing chemicals to generate Auger electrons and cause DNA double-strand breaks. First, DNA synthesis precursors containing iodine were used to place iodine on DNA. DNA binding dyes such as iodine Hoechst were investigated for Auger electron generation and DNA breaks. More recently, iodine containing nanoparticles were developed. We describe our study using tumor spheroids loaded with iodine nanoparticles and synchrotron-generated monochromatic X-rays. This study led to the demonstration that an optimum effect on DNA double-strand break formation is observed with a 33.2keV X-ray which is just above the K-edge energy of iodine.
用单色 X 射线辐照碘、金、钆等高 Z 元素会引起光电效应，包括俄歇电子的释放。放射性碘（如 I-123 和 I-125）的衰变也会导致多个事件，其中一些涉及俄歇电子的产生。这些电子能量低，仅能传播很短的距离，但对 DNA 损伤有很强的影响，包括双链断裂的产生。在本章中，我们专注于碘，并讨论了各种使用含碘化学物质产生俄歇电子并导致 DNA 双链断裂的研究。首先，使用含有碘的 DNA 合成前体将碘置于 DNA 上。研究了碘 Hoechst 等 DNA 结合染料的俄歇电子产生和 DNA 断裂情况。最近，开发了含碘的纳米颗粒。我们描述了使用碘纳米颗粒负载的肿瘤球体和同步加速器产生的单色 X 射线进行的研究。这项研究表明，用能量略高于碘 K 边的 33.2keV X 射线照射可以观察到对 DNA 双链断裂形成的最佳影响。
