Mutational spectra of bulky DNA lesions

大体积 DNA 损伤的突变谱

基本信息

批准号：
10312790
负责人：
Deyu Li
金额：
$ 36.01万
依托单位：
UNIVERSITY OF RHODE ISLAND
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-01-01 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10312790
关键词：
Area Aromatic Amines Basic Science Biological Markers Biomimetics Bypass Carbolines Carcinogens Cells Cellular Assay Chemicals Clinical DNA Adducts DNA Damage DNA lesion Development Disease Education Environment Epigenetic Process Escherichia coli Event Frequencies Genes Genetic Genome Goals Human Individual Institutes Intervention Laboratories Lesion Location Mammalian Cell Massachusetts Methods Molecular Mutation Mutation Spectra Nucleotides Oligonucleotides Pattern Plasmids Polymerase Positioning Attribute Research Research Personnel Scientist Site Symptoms System Technology Testing Toxic Environmental Substances Toxin Training Universities Walkers Work adduct authority base biological systems chemical synthesis diphenyl early onset environmental toxicology experimental study genome integrity genomic biomarker insight repaired student mentoring tool translational therapeutics tumor

项目摘要

Many environmental toxins damage DNA and cause diseases. The exposure of cells with DNA damaging agents results in the formation of a host of different DNA lesions, a subset of which can give rise to mutations. If one were to plot the frequency and type of mutation as a function of the position along a gene, a distribution is generated that is commonly referred to as a mutational spectrum. Mutational spectra are usually happened by sites at which mutagenic events occur more frequently than expected. These are mutational hotspots and the formation of hotspots can arise from three scenarios: formation, repair and replication. It is reasonable to speculate that these events are modulated by the local sequence environment surrounding the base to be modified, or the DNA lesion to be repaired or replicated. It is important for environmental scientists to provide insights into the evolutionary changes that foreshadow tumor development before overt clinical symptoms appear. This goal is crucial because some diseases, such as tumors, show few clinical symptoms until the disease has reached a late, usually fatal stage. Early onset genomic biomarkers might enable intervention to eliminate or curtail development of the disease. The biomarkers of a disease caused by a specific toxin can be obtained by studying the mutational spectra of DNA lesions generated from the toxin. Experimental studies of the mutations and mutation spectra induced by environmental toxins have traditionally focused on single mutations. However, the origins of mutational hotspots is complicated by the neighboring contexts. The selective formation, replication, and repair of a DNA lesion can, in principle, be influenced by the surrounding nucleotide environment from both 5’ and 3’ ends. A nearest-neighbor analysis of a certain DNA lesion (NXN, X = lesion, N = one of the four nucleotides) will provide a structural rationale for mutational spectra in environmental toxin related human tumors. In this proposal, we will study individual lesions of environmental toxins under all the genetic and epigenetic relevant contexts. In this project, we select two important environmental toxins, 4-amino biphenyl (ABP) and amino alpha carboline (AaC) to study the mutational spectra of their major DNA lesions and correlate with mutational signatures of diseases caused by them. The central hypothesis of this project is that DNA lesions generated by environmental toxins will cause different mutational spectra in a sequence dependent manner. The Specific Aims are: Specific Aim 1: Chemical synthesis and identification of bulky DNA adduct containing oligonucleotides. Specific Aim 2: Mutational spectra of bulky lesions in cell. Specific Aim 3: Replication bypass of lesions by translesion synthesis polymerases. At the conclusion of this project we will have demonstrated how the interaction between environmental toxins and mutational spectra. These studies shall utilize in a combination of genetic, chemical, and spectroscopic tools to understand and manipulate biological systems at the molecular level.

许多环境毒素会损害DNA并引起疾病。用DNA损伤剂暴露细胞导致形成了许多不同的DNA病变，其中一部分会引起突变。如果一个是为了将突变的频率和类型绘制为沿基因的位置的函数，分布为产生的通常称为突变频谱。突变频谱通常是通过诱变事件发生的地点比预期更频繁。这些是突变的热点热点的形成可以从三种情况下产生：形成，修复和复制。合理的推测这些事件是由基础周围的本地序列环境调节的修饰或要修复或复制的DNA病变。对于环境科学家来说，重要的是对明显临床症状前预防肿瘤发展的进化变化的见解显而易见。这个目标至关重要，因为某些疾病（例如肿瘤）几乎没有临床症状直到疾病已经达到了晚期，通常是致命的阶段。早期发作的基因组生物标志物可能使干预措施消除或减少疾病的发展。由特定毒素引起的疾病的生物标志物可能是通过研究由毒素产生的DNA病变的突变光谱获得。实验研究传统上，环境毒素引起的突变和突变光谱都集中在单个突变。但是，突变热点的起源与相邻环境变得复杂。选择性原则上，DNA病变的形成，复制和修复可能受周围核苷酸的影响来自5'和3'末端的环境。对特定DNA病变最近的邻邻分析（nxn，x =病变，n =四个核苷酸之一）将为环境毒素中的突变光谱提供结构性理由相关的人类肿瘤。在此提案中，我们将研究所有的环境毒素病变遗传和表观遗传学相关环境。在这个项目中，我们选择了两个重要的环境毒素，4-氨基二苯基（ABP）和氨基α碳蛋白（AAC）研究其主要DNA病变的突变光谱与疾病引起的疾病的突变特征相关。该项目的中心假设是环境毒素产生的DNA水平将在序列取决于不同的突变光谱方式。具体目的是：特定目标1：化学合成和宽大DNA addct的鉴定含有寡核苷酸。特定目标2：细胞中笨重病变的突变光谱。具体目标3：通过转移合成聚合酶对病变的复制旁路。在这个项目的结尾，我们将已经证明了环境毒素与突变光谱之间的相互作用。这些研究应将遗传，化学和光谱工具的结合使用来理解和操纵分子水平的生物系统。