Project 2: Oxidative DNA Damage and Genetic Instability In Models Of Intestinal

项目2：肠道模型中的氧化DNA损伤和遗传不稳定性

• 批准号: 8099687
• 负责人: Paul William Doetsch
• 金额: $ 27.86万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8099687
• 关键词: Address; Agar Gel Electrophoresis; Alkaline Single-Cell Gel Electrophoresis Assay; Animals; Attention; Cancer Model; Cell Culture System; Cell Separation; Cells; Chromosome abnormality; Chromosomes; Chronic; Colon Carcinoma; Colonic Neoplasms; DNA; DNA Damage; DNA Microarray Chip; DNA Repair; DNA Sequence Rearrangement; DNA-Directed DNA Polymerase; Development; Diagnostic Neoplasm Staging; Enzymes; Excision; Flow Cytometry; Fluorescent Probes; Fluorescent in Situ Hybridization; Gel; Genetic; Genetic Recombination; Genome; Genomics; Intestinal Cancer; Intestinal Neoplasms; Intestines; Mammalian Cell; Maps; Mediating; Mediator of activation protein; Methodology; Mitochondria; Mitochondrial DNA; Modeling; Monitor; Mus; Mutation; Nature; Normal Cell; Oxidative Stress; Pathway interactions; Phenotype; Physiological; Point Mutation; Reciprocal Translocation; Recurrence; Role; Saccharomyces cerevisiae; Series; Stress; System; Tissues; Tumor stage; Yeasts; biological adaptation to stress; cancer cell; comparative genomic hybridization; design; mouse model; mutant; oxidative DNA damage; prevent; programs; repaired; research study; response; stress management; tumor

Oxidative DMA Damage and Genetic Instability in Models of Intestinal Tumor Development It is well-established that oxidative DMA damage can cause mutations that have been implicated in tumor development. During the previous program project support period, we exploited isogenic yeast strains to determine the relationships between those pathways involved in removal/repair of oxidative DMA damage and those pathways that tolerate its presence in the genome via DNA polymerase-mediated translesion synthesis and recombination leading to genetic instability. In addition, we have established that the chronic presence of unrepaired DNA damage causes a "stress adaptation" response that leads to an increase in intracellular ROS accompanied by further increases in genetic instability and a host of physiological changes similar to the cancer cell phenotype. In project 2, we will further define the relevance of the DNA damagemediated ROS/genetic instability response within the context of it being a driver of small- and large-scale genomic rearrangements in both yeast and mammalian cells. We will also determine the relationships among oxidative DNA damage, DNA repair and genetic instability activities during various stages of tumor development in a mouse colon cancer system where mitochondrial- and Nox-mediated generators of ROS have been activated. We will also continue our collaborative studies to further elucidate the connections between oxidative mtDNA damage, mtDNA genetic instability and those systems that respond (or fail to respond) to such damage. The specific aims of this project are designed to exploit yeast to rapidly identify key ROS mediators of genetic instability and to define the nature of abnormal chromosomal changes caused by ROS as a result of DNA damage caused by exogenous and endogenous agents. The results of the yeast studies will be used to focus attention on similar relationships that we hypothesize will exist during the development of mammalian colon tumors where increasing intracellular ROS functions as a driver (via oxidative DNA damage) of small- and large-scale genomic changes, from point mutations to chromosomal aberrations, including amplifications, deletions, and non-reciprocal translocations. The results of these studies should provide a picture of the extent to which ROS functions as the mediator of genetic instability during colon tumor development in mammalian intestinal cells.

肠道肿瘤模型中DNA氧化损伤和遗传不稳定性的研究 众所周知，氧化性DMA损伤可导致与肿瘤相关的突变。 发展在上一个计划项目支持期间，我们开发了同基因酵母菌株， 确定参与去除/修复氧化DMA损伤的途径之间的关系 以及那些通过DNA聚合酶介导的跨损伤耐受其存在于基因组中的途径 合成和重组导致遗传不稳定。此外，我们已经确定， 未修复的DNA损伤的存在会引起“压力适应”反应，导致细胞凋亡增加。 细胞内ROS伴随着遗传不稳定性的进一步增加和许多生理变化 与癌细胞表型相似。在项目2中，我们将进一步确定DNA损伤介导的相关性， ROS/遗传不稳定性反应在它是小规模和大规模的驱动力的背景下， 酵母和哺乳动物细胞中的基因组重排。我们还将确定 在肿瘤的不同阶段，氧化性DNA损伤、DNA修复和遗传不稳定性活动 在小鼠结肠癌系统中的发展，其中线粒体和Nox介导的ROS发生器 已经被激活了我们还将继续合作研究，进一步阐明 线粒体DNA氧化损伤、线粒体DNA遗传不稳定性和那些响应（或未能响应） 对这种损害的反应。 本项目的具体目标是利用酵母菌快速识别关键的ROS介质， 遗传不稳定性，并确定ROS引起的异常染色体变化的性质， 外源性和内源性因素引起的DNA损伤。将使用酵母研究的结果 把注意力集中在我们假设在发展过程中存在的类似关系上， 哺乳动物结肠肿瘤，其中增加的细胞内ROS起驱动作用（通过氧化DNA 损伤）的小规模和大规模的基因组变化，从点突变到染色体畸变， 包括扩增、缺失和非相互易位。这些研究的结果应该 提供了一个图片的程度，ROS功能作为调解人的遗传不稳定性，在结肠 哺乳动物肠细胞中的肿瘤发展。