Altered Nuclear Protein Interactions and Radiosensitizat

改变核蛋白相互作用和放射增敏

• 批准号: 6989549
• 负责人: JOSEPH L ROTI ROTI
• 金额: $ 16.09万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6989549
• 关键词: athymic mouse; conformation; heat shock proteins; heat stimulus; hyperthermia; nuclear proteins; protein binding; protein localization; protein protein interaction; radiation sensitivity; radiosensitizer; tissue /cell culture

Hyperthermia is one of the most effective radiosensitizers known. Therefore, the goal of Project 1 is to delineate the mechanisms of radiosensitization by short-duration moderate hyperthermia and the mechanism(s) by which radiosensitization is increased via increasing thermal dose, so that the cellular targets for enhancers of heat-induced radiosensitization will be defined. It is known that hyperthermia enhances protein binding to nuclear components, leading to altered protein-protein interactions throughout the nucleus. Accumulating evidence suggests that some of these changes cause radiosensitization. However, the exact changes in nuclear protein interactions that contribute to radiosensitization remain unknown. Thus, the objectives of the proposed work are to delineate the changes in nuclear protein associations induced by short duration, moderate hyperthermia that lead to increased radiosensitivity. The first step will be to determine if the heat-induced translocation of the DNA-repair protein, Mrel 1, from the nucleus to the cytoplasm and/or its dissociation from its functional partners causes radiosensitization by short-duration, moderate hyperthermia (Specific Aim 1). Second, we will determine which changes in nuclear protein association contribute to increasing radiosensitization by increasing thermal dose. The second part of the hypothesis is that the heat-induced increase in the binding of proteins to DNA-nuclear matrix attachment regions contribute to increased radiosensitivity at thermal doses above the minimum required for radiosensitization (e.g., acute hyperthermia). If altered protein conformations are responsible for changes in protein associations that lead to heat-induced radiosensitization, it is likely that recovery from these effects would require an association between the protein and a molecular chaperone(s) e.g., hsp70, which will be tested in Specific Aim 3. The hypothesis that an increasing spectrum of radiosensitizing effects contribute to enhanced radiosensitization will be tested in Specific Aim 4, by determining if moderate hyperthermia, plus an enhancer of HIR produces at least some of the radiosensitizing effects of acute hyperthermia.

热疗是已知的最有效的放射增敏剂之一。因此，项目1的目标是描述短时间中度高温的放射增敏机制以及通过增加热剂量增加放射增敏的机制，以便确定热诱导放射增敏增强剂的细胞靶点。已知高温增强蛋白质与核组分的结合，导致整个核中蛋白质-蛋白质相互作用的改变。越来越多的证据表明，这些变化中的一些会引起放射增敏。然而，导致放射增敏的核蛋白相互作用的确切变化仍然未知。因此，拟议的工作的目标是描绘的变化，核蛋白协会引起的短时间，中度高温，导致放射敏感性增加。第一步将是确定DNA修复蛋白Mrel 1从细胞核到细胞质的热诱导易位和/或其与其功能伴侣的解离是否通过短时间中度高温引起放射增敏（特异性目的1）。其次，我们将确定核蛋白结合的哪些变化有助于通过增加热剂量来增加放射增敏。该假设的第二部分是热诱导的蛋白质与DNA-核基质附着区结合的增加有助于在高于放射增敏所需的最小值的热剂量下增加放射敏感性（例如，急性高热）。如果改变的蛋白质构象是导致热诱导的放射增敏的蛋白质缔合变化的原因，那么从这些效应中恢复可能需要蛋白质与分子伴侣之间的缔合，例如，hsp 70，将在具体目标3中进行测试。将在特定目标4中通过确定中度高热加上HIR增强剂是否产生至少部分急性高热的放射增敏效应，来检验放射增敏效应谱增加有助于增强放射增敏的假设。