MECHANISMS OF DNA DAMAGE TRIGGERED S PHASE CHECKPOINTS

DNA 损伤触发 S 相检查点的机制

• 批准号: 6626784
• 负责人: THOMAS MELENDY
• 金额: $ 26.45万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-12 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6626784
• 关键词: DNA binding protein; DNA damage; DNA directed DNA polymerase; DNA replication; alkylating agents; antineoplastics; laboratory rabbit; phosphatidylinositol 3 kinase; phosphoproteins; posttranslational modifications; protein structure function; simian virus 40; virus DNA

DESCRIPTION (adapted from applicant's abstract): The goal of this research is to identify the mechanisms by which the S-phase DNA damage checkpoint responses arrest DNA replication. These checkpoints are the way cells temporarily stop passage through the cell cycle to allow time for repair of DNA damage, prior to cell division. If these checkpoints don't act appropriately, there are various possible outcomes. Minor DNA damage can lead to permanent mutations in the genome. Greater DNA damage can lead to chromosomal breakage, rearrangement, translocations, and even catastrophic cell division. The principal investigator's preliminary studies have shown that he can use an SV4O in vitro DNA replication system, which is supported predominantly by human cell extracts, to biochemically investigate S phase DNA damage dependent checkpoints. Pretreatment of cultured human cells with DNA damaging agents leads to inhibition of in vitro SV4O DNA replication that parallels the inhibition of chromosomal DNA replication in vivo. As model drugs, the principal investigator has chosen to use two anti-cancer chemotherapeutics. He has shown that these two drugs trigger different mechanisms for arresting DNA replication, adozelesin inactivates a known cellular DNA replication protein, RPA, while bizelesin induces the presence of a trans-acting DNA replication inhibitor. The goals of this proposal are to understand how adozelesin results in the inactivation of RPA, and to identify the trans-inhibitor induced by bizelesin, identify the replication protein that is the target of this trans-inhibitor, and to determine how this second mechanism results in the inhibition of DNA replication. During their progression, most forms of cancer have lost one or more of their DNA-damage checkpoint responses. This likely explains why most cancer therapies generally destroy cancer cells through catastrophic cell division. Elucidating these DNA-damage dependent checkpoint pathways and understanding the mechanisms of how they work, will ultimately aid in the design of better anti-cancer therapeutics, and will provide information that will allow for improved therapeutic strategies for particular tumors.

描述（根据申请人的摘要改编）：这项研究的目的是 确定S期DNA损伤检查点响应的机制 阻止DNA复制。这些检查点是单元格暂时停止的方式 通过细胞周期通过，以便在DNA损伤之前修复时间 细胞分裂。如果这些检查站没有适当的行动，则有各种各样的 可能的结果。轻微的DNA损伤会导致永久突变 基因组。更大的DNA损伤会导致染色体断裂，重排， 易位，甚至灾难性细胞分裂。 主要研究者的初步研究表明，他可以使用 SV4O体外DNA复制系统，主要由人类支持 细胞提取物，以生化研究S期DNA损伤依赖性 检查点。用DNA破坏剂对培养的人类细胞进行预处理 导致抑制体外SV4O DNA复制，与 在体内抑制染色体DNA复制。作为模型药物， 首席研究员选择使用两种抗癌化学治疗药。他 已经表明，这两种药物会触发不同的机制来阻止DNA 复制，沉淀素使已知的细胞DNA复制蛋白失活， rpa，而双扎林蛋白诱导跨作用DNA复制的存在 抑制剂。该提案的目标是了解变性结果如何 在RPA失活时，并确定了由 bizelesin，识别这是目标的复制蛋白 跨抑制剂，并确定这种第二种机制如何导致 抑制DNA复制。 在他们的进展过程中，大多数形式的癌症都失去了其中一个或多个 DNA破坏检查点响应。这可能解释了为什么大多数癌症疗法 通常通过灾难性细胞分裂破坏癌细胞。阐明 这些依赖DNA损伤的检查点途径并了解机制 他们的工作方式最终将有助于设计更好的反癌 治疗剂，并将提供可以改进的信息 特定肿瘤的治疗策略。