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.

许多环境毒素会损伤 DNA 并导致细胞接触 DNA 损伤剂。导致形成一系列不同的 DNA 损伤，其中的一个子集可能会引起突变。如果要将突变的频率和类型绘制为基因位置的函数，则分布为产生的突变谱通常被称为突变谱。突变事件发生频率高于预期的位点这些是突变热点和突变点。热点的形成可以由三种情况产生：形成、修复和复制，这是合理的。推测这些事件是由基地周围的局部序列环境调制的修改或修复或复制 DNA 损伤对于环境科学家来说非常重要。深入了解在明显的临床症状之前预示肿瘤发展的进化变化这一目标至关重要，因为某些疾病（例如肿瘤）在出现之前很少表现出临床症状。疾病已达到晚期，通常是致命的阶段，早期发病的基因组生物标志物可能有助于干预。消除或抑制疾病的发展可以是由特定毒素引起的疾病的生物标志物。通过研究由毒素引起的损伤的DNA突变谱而获得。环境毒素引起的突变和突变谱传统上集中于单一突变然而，突变热点的起源因邻近环境的选择性而变得复杂。 DNA损伤的形成、复制和修复原则上会受到周围核苷酸的影响特定 DNA 损伤的最近邻分析（NXN，X = 损伤，N）。 = 四种核苷酸之一）将为环境毒素突变谱提供结构原理在本提案中，我们将研究所有环境毒素下的个体病变。在这个项目中，我们选择了两种重要的环境毒素，4-氨基。联苯 (ABP) 和氨基α咔啉 (AaC) 研究其主要 DNA 损伤的突变谱与它们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损伤会导致序列依赖性的不同突变谱具体目标是：具体目标 1：大体积 DNA 加合物的化学合成和鉴定。含有寡核苷酸的具体目标 2：细胞中大块病变的突变谱。在这个项目结束时，我们将通过跨损伤合成聚合酶来复制旁路损伤。这些研究已经证明了环境毒素与突变谱之间的相互作用。应结合使用遗传、化学和光谱工具来理解和操纵分子水平的生物系统。