DNA DAMAGE RESPONSE AND DNA REPLICATION

DNA 损伤反应和 DNA 复制

• 批准号: 6624428
• 负责人: JEAN GAUTIER
• 金额: $ 28.88万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6624428
• 关键词: DNA damage; DNA repair; DNA replication; Xenopus oocyte; ataxia telangiectasia; biological signal transduction; cell cycle; cell free system; cyclin dependent kinase; growth inhibitors; light adverse effect; phosphorylation; protein kinase; ultraviolet radiation

Following DNA damage cells activate a multi-faceted response including cell cycle arrest and the coordinated activation of DNA repair. Failure to activate or to coordinate the DNA-damage induced signal transduction pathways can lead to chromosome breakage and loss, and to the propagation of mutations. Indeed, several cancer-prone syndromes reflect defects in the DNA damage response. These include, but are not limited to, Ataxia-Telangiectasia, Nijmegen Breakage Syndrome, Ataxia-Telangiectasia Like Disorder, Li-Fraumeni Syndrome and familial forms of breast and cervical cancers. Our long-term objective is to understand the mechanisms by which the different facets of the DNA damage response are integrated within cell cycle progression at the time of DNA replication. The ability to undergo DNA replication in the presence of DNA damage, called Radio-Resistant DNA Synthesis (RDS), is a hallmark of the cellular phenotypes of cancer-prone disorder as well as of tumor cells. We have established a cell-free system derived from Xenopus eggs that recapitulates different aspects of the DNA damage response. In particular, we have been able to identify a novel ATM- dependent cell cycle checkpoint that prevents initiation of DNA replication. We will determine whether the Xenopus homologues of Chk1 and/or Chk2/Cds1 are components of this pathway. We will also determine whether Wee1, Myt1 and/or Cdc25 are components of the pathway. We will take advantage of this cell-free system to identify which type of damages can elicit a checkpoint in vitro and whether such responses are ATM or ATR-dependent. Finally, we will examine how ATM and Mre11 complex participate in the coordinated and harmonious response to DNA damage and how cell cycle arrest is integrated with DNA repair. We anticipate that these studies will help understand some of the biochemical pathways activated by DNA damage and that, in turn; it will provide valuable information on how the DNA damage response can be impaired or lost in the case of cancer.

DNA损伤后，细胞激活多方面的反应，包括细胞周期停滞和DNA修复的协调激活。 未能激活或协调DNA损伤诱导的信号转导途径可导致染色体断裂和丢失，以及突变的传播。 事实上，几种易患癌症的综合征反映了DNA损伤反应的缺陷。 这些包括但不限于共济失调-毛细血管扩张症、奈梅亨断裂综合征、共济失调-毛细血管扩张症样障碍、Li-Fraumeni综合征和家族形式的乳腺癌和宫颈癌。我们的长期目标是了解DNA损伤反应的不同方面在DNA复制时整合在细胞周期进程中的机制。在存在DNA损伤的情况下进行DNA复制的能力，称为抗辐射DNA合成（RDS），是癌症易感性疾病以及肿瘤细胞的细胞表型的标志。我们已经建立了一个来自非洲爪蟾卵的无细胞系统，该系统概括了DNA损伤反应的不同方面。特别是，我们已经能够鉴定一种新的ATM依赖性细胞周期检查点，其阻止DNA复制的起始。我们将确定是否Chk 1和/或Chk 2/Cds 1的爪蟾同源物是这一途径的组成部分。 我们还将确定Wee 1，Myt 1和/或Cdc 25是否是该途径的组成部分。我们将利用这种无细胞系统来确定哪种类型的损伤可以在体外引起检查点，以及这种反应是ATM还是ATR依赖性的。 最后，我们将研究ATM和Mre 11复合体如何参与对DNA损伤的协调一致的反应，以及细胞周期阻滞如何与DNA修复相结合。我们预计，这些研究将有助于了解DNA损伤激活的一些生化途径，反过来，它将提供有关DNA损伤反应如何在癌症中受损或丢失的有价值的信息。