Modeling the Responsiveness of Sensitive Populations to Genotoxic Agents Using DNA Repair Inhibitors

项目摘要 众所周知，传统的毒理学检测方法存在一个严重的缺陷。具体地说，他们使用 有限数量的细胞系和啮齿动物品系不能提供有关毒性反应的信息，这可能 发生在敏感人群中。尽管研究了大量的细胞系和实验室啮齿动物 模型可以从理论上解决这个问题，但这并不是一个实用的答案。有太多的遗产 正在为此开发化学物质和新的化学物质，以代表常规测试方案。 幸运的是，在遗传毒理学领域，存在一个解决方案。我们的创新方法考虑到了 受试者之间对基因毒性药物敏感性的差异主要是由于DNA修复的差异 容量。我们的项目将开发一个高效、高通量、体外遗传毒性检测平台，为 关于化学品可能在原型和敏感人群中造成DNA损伤的信息。 我们建议的方法的高效率在一定程度上是因为我们决定研究单个p53- 有能力的人类细胞系(TK6)产生典型的遗传毒性反应谱。敏感人群 反应将通过将细胞共同暴露于每种测试化学物质，并结合一组小的 分子DNA修复抑制剂。这些抑制剂将被选择来覆盖每一个主要的DNA修复 小路。除了我们使用DNA修复抑制剂来有效地模拟敏感人群外，其他 我们项目的创新方面包括我们使用多路DNA损伤检测来覆盖多个 遗传毒性和细胞毒性的生物标记物，以及最先进的基准剂量软件来表征 将为所研究的每种化学物质生成的剂量-反应关系家族。一旦沦为 实践中，我们将以一套试剂格式化试剂的形式提供化验，也可以通过收费的方式提供 测试。

Project Summary It is well recognized that conventional toxicology assays exhibit a crucial deficiency. Specifically, their use of limited numbers of cell lines and rodent strains does not provide information about toxic responses that may occur in sensitive human populations. Although studying very large numbers of cell lines and laboratory rodent models could theoretically address this issue, it is not a practical answer. There are simply too many legacy chemicals and new chemical substances being developed for this to represent a routine testing scheme. Fortunately, in the area of genetic toxicology, a solution exists. Our innovative approach takes into account the fact that inter-subject differences in sensitivity to genotoxic agents is predominately due to variable DNA repair capacity. Our project will develop an efficient, high throughput, in vitro genotoxicity assay platform that provides information about chemicals’ potential to cause DNA damage in prototypical and sensitive human populations. The high efficiency of our proposed approach is in part explained by our decision to study a single p53- competent human cell line (TK6) to generate prototypical genotoxic response profiles. Sensitive population responses will be modelled by co-exposing cells to each test chemical in combination with a panel of small molecule DNA repair inhibitors. These inhibitors will be chosen to cover each of the major DNA repair pathways. In addition to our use of DNA repair inhibitors to efficiently mimic sensitive populations, other innovative aspects of our project include our use of a multiplexed DNA damage assay to cover multiple biomarkers of genotoxicity and cytotoxicity, and state-of-the-art benchmark dose software to characterize the family of dose-response relationships that will be generated for each chemical studied. Once reduced to practice, we will make the assay available as a set of kit-formatted reagents, and also through fee-for-service testing.