Li L, Story M, Legerski R J
Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
Int J Radiat Oncol Biol Phys. 2001 Mar 15;49(4):1157-62. doi: 10.1016/s0360-3016(00)01524-8.
The purpose of this report is to provide current perspectives on studies of DNA damage and cell cycle response after ionizing radiation, and their applications in radiation oncology.
Presentations at the Seventh Annual Radiation Oncology Workshop, held at the International Festival Institute at Round Top, TX, were summarized.
Eighteen speakers presented their current work covering a wide range of studies on cellular responses to ionizing radiation. These presentations and discussions form the framework of our report.
In response to ionizing radiation, cells immediately activate a series of biochemical pathways that promote cell survival while maintaining genetic integrity. The main cellular defense system against ionizing radiation exposure is composed of two distinct types of biochemical pathways, that is, the DNA damage cell cycle checkpoint pathways and the DNA repair pathways. The DNA damage checkpoint pathways are activated directly by DNA damage, while the repair pathways are constitutively active and are likely modulated by checkpoint signals. Discussions here emphasize that the ATM protein is a central component of the ionizing radiation-responsive pyramid and is essential for activating divergent molecular responses that involve transcriptional regulation, cell cycle arrest, and modulation of DNA repair. The relationship between homologous recombinational repair and nonhomologous end joining of double-strand breaks is also discussed.
本报告旨在提供关于电离辐射后DNA损伤及细胞周期反应研究的当前观点，以及它们在放射肿瘤学中的应用。
总结了在德克萨斯州圆顶国际艺术节研究所举行的第七届年度放射肿瘤学研讨会上的发言。
18位发言者介绍了他们目前的工作，内容涵盖了对细胞对电离辐射反应的广泛研究。这些发言和讨论构成了我们报告的框架。
作为对电离辐射的反应，细胞会立即激活一系列生化途径，这些途径在维持遗传完整性的同时促进细胞存活。针对电离辐射暴露的主要细胞防御系统由两种不同类型的生化途径组成，即DNA损伤细胞周期检查点途径和DNA修复途径。DNA损伤检查点途径由DNA损伤直接激活，而修复途径则持续活跃，并可能受到检查点信号的调节。此处的讨论强调，ATM蛋白是电离辐射反应金字塔的核心组成部分，对于激活涉及转录调控、细胞周期停滞和DNA修复调节的不同分子反应至关重要。还讨论了双链断裂的同源重组修复与非同源末端连接之间的关系。
