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（改编自申请人的摘要）：这项研究的目标是 确定 S 期 DNA 损伤检查点反应的机制 阻止DNA复制。这些检查点是细胞暂时停止的方式 穿过细胞周期，以便有时间修复 DNA 损伤，然后 细胞分裂。如果这些检查点没有采取适当的行动，就会出现各种情况 可能的结果。轻微的DNA损伤可能导致DNA的永久性突变 基因组。更大的DNA损伤会导致染色体断裂、重排、 易位，甚至灾难性的细胞分裂。 首席研究员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，用于生化研究 S 期 DNA 损伤依赖性 检查站。用 DNA 损伤剂预处理培养的人类细胞 导致体外 SV4O DNA 复制的抑制，与 抑制体内染色体DNA复制。作为模型药物， 主要研究者选择使用两种抗癌化疗药物。他 已表明这两种药物会触发不同的 DNA 阻滞机制 复制，adozelesin 灭活已知的细胞 DNA 复制蛋白， RPA，而比泽来辛诱导反式作用 DNA 复制的存在 抑制剂。该提案的目标是了解阿多来辛的结果 RPA 失活，并鉴定由以下因素诱导的反式抑制剂 bizelesin，确定作为该目标的复制蛋白 反式抑制剂，并确定第二种机制如何导致 抑制DNA复制。 在其进展过程中，大多数形式的癌症都失去了一种或多种 DNA 损伤检查点反应。这可能解释了为什么大多数癌症疗法 通常通过灾难性的细胞分裂来破坏癌细胞。阐明 这些 DNA 损伤依赖性检查点通路并了解其机制 了解它们如何发挥作用，最终将有助于设计更好的抗癌药物 疗法，并将提供有助于改进的信息 针对特定肿瘤的治疗策略。