MOLECULAR BIOLOGY OF CAMPTOTHECIN INDUCED DNA DAMAGE

喜树碱引起的 DNA 损伤的分子生物学

• 批准号: 6377080
• 负责人: ROBERT M SNAPKA
• 金额: $ 19.85万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-08 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6377080
• 关键词: DNA damage; DNA replication; DNA topoisomerases; RNA splicing; ataxia telangiectasia; camptothecin; deafness; dwarfism; enzyme activity; enzyme inhibitors; genetic transcription; molecular biology; phosphoester ligase; retina degeneration; simian virus 40; tissue /cell culture; virus DNA

Camptothecins are a very promising group of strong topoisomerase I poisons that have shown good activity against a variety of human cancers in clinical trials. Several key contributions to our understanding of the cytotoxic mechanisms of camptothecins have been made with studies of simian virus 40 (SV40), a small double strand DNA virus which makes such extensive use of host cell chromosomal proteins and enzymes of DNA replication and transcription that it is considered a "minichromosome" and model for the mammalian replicon. As a model system, SV40 has unique advantages and has made many contributions to our understanding of mammalian DNA replication and transcription. The hypothesis of this proposed study is that our understanding of the molecular biology of camptothecin action can be significantly advanced by two developments of the SV40 model system: (1) the study of camptothecin-resistant mutants of CV-1 host cells for SV40 infections and (2) studies using mutants of SV40 with greatly increased infectivity for human cells. The primary goal of the studies is to understand the structure and processing of camptothecin-induced DNA lesions and how these can be modulated by other treatments. The unique advantages of the SV40 system will allow us to analyze disruptions in DNA replication and transcription in unusual molecular detail. Secondary goals include complete characterization of the camptothecin resistant CV-1 cell mutants, studies of camptothecin effects on DNA replication in human genetic instability syndromes hypersensitive to camptothecins and understanding of the roles of topoisomerases I and IIbeta in transcription. The rational for the studies is that improved understanding of camptothecin-induced damage and its processing will provide valuable information for the design of new drugs of this class and for new treatment combinations.

喜树碱是一类非常有前途的强效拓扑异构酶 I 毒物，在临床试验中显示出对多种人类癌症的良好活性。 对猿猴病毒 40 (SV40) 的研究对我们了解喜树碱的细胞毒性机制做出了几项关键贡献，猿猴病毒 40 是一种小型双链 DNA 病毒，它广泛利用宿主细胞染色体蛋白和 DNA 复制和转录酶，因此被认为是“微型染色体”和哺乳动物复制子的模型。 作为一个模型系统，SV40具有独特的优势，为我们理解哺乳动物DNA复制和转录做出了许多贡献。 这项拟议研究的假设是，我们对喜树碱作用的分子生物学的理解可以通过 SV40 模型系统的两项发展显着推进：（1）针对 SV40 感染的 CV-1 宿主细胞的喜树碱抗性突变体的研究和(2)使用SV40突变体进行的研究，其对人类细胞的感染性大大增加。 这些研究的主要目标是了解喜树碱引起的 DNA 损伤的结构和加工，以及如何通过其他治疗来调节这些损伤。 SV40 系统的独特优势将使我们能够以不寻常的分子细节分析 DNA 复制和转录的破坏。 次要目标包括完整表征喜树碱抗性 CV-1 细胞突变体、研究喜树碱对喜树碱过敏的人类遗传不稳定综合征中 DNA 复制的影响，以及了解拓扑异构酶 I 和 IIbeta 在转录中的作用。 这些研究的理由是，提高对喜树碱引起的损伤及其加工的了解将为设计此类新药和新的治疗组合提供有价值的信息。