MECHANISMS OF RDIATION RESPONSE AND ADP RIBOSE METABOLISM

辐射响应和 ADP 核糖代谢机制

• 批准号: 6269831
• 负责人: VICENTE NOTARIO
• 金额: $ 20.32万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6269831
• 关键词: ADP ribosylation; DNA binding protein; DNA damage; DNA footprinting; DNA repair; adenine phosphoribosyltransferase; apoptosis; enzyme activity; flow cytometry; gel mobility shift assay; genetic transcription; ionizing radiation; molecular cloning; molecular pathology; neoplasm /cancer radiation therapy; neoplastic cell culture for noncancer research; polymerase chain reaction; protein metabolism; proteolysis; radiation sensitivity; transfection /expression vector; western blottings

The overall objective of this proposal is to investigate the role of poly(ADP-ribose) polymerase (PARP) in the cellular response to ionizing radiation injury. Evidence accumulated from experiments performed by us and others indicates that, although PARP appears to be an element in the G2 checkpoint in mammalian cells, it is not an essential gene for DNA replication or the nucleotide excision pathway for DNA repair. These findings support that the cellular radiation response rely on effective poly(ADP-ribose) metabolism. We hypothesize that the level and mode of action of activated PARP is critical for recovery from ionizing radiation damage to DNA, and that perturbations in the normal regulatory systems for PARP levels and activity by excessive DNA damage result in the potentiation of the apoptosis pathway in the cellular response. Using Ewing's sarcoma (EWS) cells as the primary experimental model system for radiosensitivity and high PARP levels, we propose an experimental approach designed to: 1) study the transcriptional regulation of PARP and determine if it is altered by radiation exposure, 2) identify proteolytic systems involved in the turnover of the PARP gene product, and 3) establish the participation and role of the PARP-turnover proteases in the response to radiation-induced DNA damage and apoptosis. Data from these experiments will identify molecular events associated with the cellular response to ionizing radiation. An important limiting factor in tumor treatment by radiation therapy is the intrinsic radiosensitivity of tumor cells. Understanding the mechanisms of radiation response, particularly those potentiating tumor cell apoptosis, will allow the development of strategies for improving the clinical therapeutic ratio.

本提案的总体目标是调查 聚（ADP-核糖）聚合酶（PARP）在细胞对电离 辐射损伤从我们进行的实验中积累的证据 其他人指出，虽然PARP似乎是一个元素， 哺乳动物细胞中的G2检查点，它不是DNA的必需基因 复制或用于DNA修复的核苷酸切除途径。这些 研究结果支持细胞辐射反应依赖于有效的 聚（ADP-核糖）代谢。我们假设， 活化PARP的作用对于电离辐射的恢复至关重要 DNA损伤，以及正常调节系统的干扰， PARP水平和活性的过度DNA损伤的结果， 在细胞反应中增强凋亡途径。 以尤文氏肉瘤（EWS）细胞为主要实验模型系统 对于辐射敏感性和高PARP水平，我们提出了一种实验性的 该方法旨在：1）研究PARP的转录调控， 确定它是否因辐射暴露而改变，2）鉴定蛋白水解 参与PARP基因产物周转的系统，以及3） 建立PARP周转蛋白酶在蛋白质合成中的参与和作用。 对辐射诱导的DNA损伤和凋亡的反应。 来自这些实验的数据将确定与以下相关的分子事件： 细胞对电离辐射的反应一个重要的限制因素 在肿瘤放射治疗中， 肿瘤细胞。了解辐射反应的机制， 特别是那些增强肿瘤细胞凋亡的药物， 制定提高临床治愈率的策略。