A Drosophila model for the electrophile counter-attack chemoprevention strategy

描述（由申请人提供）：本申请的长期目标是通过建立黑腹果蝇作为Keap 1-Nrf 2信号传导的遗传和药理学研究平台来加速癌症化学预防研究。初步研究结果表明，果蝇同源物Nrf 2和Keap 1（CNC-C和dKeap 1，分别）包括一个细胞保护模块，响应氧化剂和化学预防剂oltipraz，调节应激诱导基因，并赋予增加的耐受性的苍蝇氧化应激。该项目将描述奥替普拉和新合成三萜类化合物（由Michael B博士提供）的作用。Sporn，达特茅斯医学院）对果蝇Nrf 2（CNC-C）信号传导激活的研究。功能实验将确定这些化学预防药物在果蝇中的作用机制和生理效应。通过在申请人实验室开发的Nrf 2或Keap 1功能获得或丧失的遗传背景中进行实验，将绘制介导抗氧化反应元件活化和Nrf 2靶基因表达的信号通路。生物测定将监测奥替普拉和三萜类化合物对生物体对氧化应激源的抵抗力及其寿命的影响。总之，这些实验将建立一个遗传学上易于处理的系统，用于研究完整生物体中Nrf 2信号传导的药理学操作的影响，该系统与现有的啮齿动物，鱼类和基于细胞的模型系统互补。这项工作将是果蝇遗传学的力量将有助于解决化学预防的关键临床问题的起点。在这些初步研究完成后，未来的研究将成为可行的，将分析Nrf 2系统与体内应激反应和防御的其他机制的整合，为合理设计组合靶向策略提供基础。此外，对果蝇中化学预防剂的长期生物效应的评估可以帮助优先考虑具有生活质量促进特征的药物，以进一步进行临床前开发。最后，果蝇可以成为一个平台，在体内快速的结构-活性关系（SAR）分析的Nrf 2激活剂。

DESCRIPTION (provided by applicant): The long-term objective of this application is to accelerate cancer chemoprevention research by establishing Drosophila melanogaster as a platform for the genetic and pharmacological study of Keap1-Nrf2 signaling. Preliminary findings suggest that the Drosophila homologues of Nrf2 and Keap1 (CNC-C and dKeap1, respectively) comprise a cell protective module that responds to oxidants and to the chemopreventive agent oltipraz, regulates stress-inducible genes, and confers increased tolerance of the fly to oxidative stress. This project will characterize the effects of oltipraz and of the new synthetic triterpenoids (provided by Dr Michael B. Sporn, Dartmouth Medical School) on the activation of Drosophila Nrf2 (CNC-C) signaling. Functional experiments will determine the mechanisms of action and physiological effects of these chemopreventive drugs in Drosophila. By conducting experiments in genetic backgrounds of gain- or loss-of-function for Nrf2 or Keap1 that have been developed in the laboratory of the applicant, the signaling pathway mediating the activation of the Anti-oxidant Response Element and the expression of Nrf2 target genes will be charted. Biological assays will monitor the effects of oltipraz and triterpenoids on the organism's resistance to oxidative stressors and on its lifespan. Together, these experiments will establish a genetically tractable system for studying the effects of pharmacological manipulation of Nrf2 signaling in an intact organism that is complementary to existing rodent, fish, and cell-based model systems. This work will be the starting point from which the power of Drosophila genetics will help to address crucial clinical issues of chemoprevention. Future research that will become feasible upon completion of these pilot studies will analyze the integration of the Nrf2 system with other mechanisms of stress response and defense in vivo, providing a basis for rational design of combinatorial targeting strategies. Furthermore, the evaluation of long-term organismal effects of chemopreventive agents in Drosophila could help prioritize drugs with quality-of-life promoting profiles for further preclinical development. Finally, Drosophila could become a platform for rapid in vivo structure-activity relationship (SAR) analyses of Nrf2 activators.