Burden and signatures of somatic mutations in genomes of healthy individuals.

健康个体基因组体细胞突变的负担和特征。

• 批准号: 10290546
• 负责人: Natalie Saini
• 金额: $ 24.9万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-11-20 至 2023-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10290546
• 关键词: Address; Alleles; Bar Codes; Bioinformatics; Biological Assay; Biopsy; Cell Culture Techniques; Cell Line; Cells; Clone Cells; CpG dinucleotide; Cytidine Deaminase; Cytosine; DNA; DNA Damage; DNA Repair; DNA Repair Gene; DNA Repair Pathway; DNA-Directed DNA Polymerase; Data; Deamination; Defect; Disease; Endogenous Factors; Environmental Risk Factor; Exposure to; Fibroblasts; Genes; Genetic; Genetic Polymorphism; Genetic Recombination; Genetic Variation; Genome; Genomic Instability; Goals; Growth; Hair follicle structure; Health; Human; Human Cell Line; Human body; Individual; Institutes; Intrinsic factor; Lead; Lesion; Light; Lymphocyte; Malignant Neoplasms; Measures; Minor; Mus; Mutagenesis; Mutagenicity Tests; Mutagens; Mutate; Mutation; National Institute of Environmental Health Sciences; Participant; Pathologic; Pathologic Mutagenesis; Pathology; Plasmids; Population; Predisposition; Prevention strategy; Prevention therapy; Process; Proteins; Registries; Reporter; Research Personnel; Role; Sampling; Single Nucleotide Polymorphism; Site; Skin; Somatic Cell; Somatic Mutation; Source; Specificity; System; Testing; Tissues; Ultraviolet Rays; Variant; Yeasts; base; biobank; cancer genome; cancer type; carcinogenesis; career; cell immortalization; cell type; design; disorder prevention; exome; genetic manipulation; genetic variant; genome analysis; genome sequencing; genome-wide; individual variation; insight; knowledge base; melanocyte; mutant; normal aging; oxidative damage; protein function; repaired; single molecule real time sequencing; tumor; whole genome

Somatic mutations accumulate over the lifetime of an individual due to both genetic and environmental factors. It is becoming evident that somatic genome changes are associated with a host of pathologies including cancers. Sequencing genomes of different cancer types suggested that mutation loads vary between cell types and across the body. The variations have been associated with differential exposure to DNA damaging agents and the replicative potential of the cells. In addition, mutation loads due to DNA damaging lesions would also be dependent on the ability of the cells to repair damage in an error-free manner. However, the mutation loads attributable to environmental and intrinsic factors across cell types in healthy individuals are not known. Also, it is not known how polymorphisms within DNA repair genes compromise repair efficiency and alter the mutation landscape in cells exposed to environmental DNA damage as well as in unexposed cells. The goal of this proposal is to determine the extent of somatic genome changes within the body and in different individuals and to examine the mechanisms that contribute to this variability. To address this goal, I will explore the following aims. In Aim1, I will directly analyze the impact of DNA repair polymorphisms associated with cancers on DNA repair capacity using orthogonal systems. Using plasmid-based host cell reactivation assays, I will test repair efficiency in lymphocytes with homozygous minor (mutant) or major (wild-type) alleles. I will also determine if these mutant human genes increase mutation and recombination rates in yeast and human cells upon exposure to exogenous DNA damage and during unchallenged growth. In Aim2, I will determine the role of deleterious single nucleotide polymorphisms (SNPs) in DNA repair genes. Mutations leading to loss of a functional MBD4 glycosylase, have been shown to increase CT changes in CpG dinucleotides in cancer genomes. I will test if SNPs that are predicted to be deleterious to the MBD4 protein also increase mutation loads and altering signatures in somatic cells from healthy individuals. In Aim3, I will estimate mutation loads in different cell-types isolated from the same individuals from different body sites. I will assess the contributions of mutation signatures associated with known environmental and endogenous mutagenic sources to mutation loads in the samples. The completion of the studies in this proposal will provide me with expertise in cell culture, genetic manipulation of human cell lines and bioinformatics, paving the way for a successful career as an independent researcher. Significance: These studies will increase our understanding of the interplay of environmental and genetic factors that determine somatic mutagenesis. These results are important for understanding the susceptibility of individuals to cancers and other diseases associated with somatic mutagenesis, and in designing individual- specific disease prevention strategies.

由于遗传和环境因素，体细胞突变在个体的一生中积累。 越来越明显的是，体细胞基因组变化与许多病理学相关，包括 癌的对不同类型癌症的基因组测序表明， 类型和整个身体。这些变化与DNA损伤的不同暴露有关 药物和细胞的复制潜能。此外，由于DNA损伤损伤导致的突变负荷 还将取决于细胞以无差错的方式修复损伤的能力。但 在健康个体中，归因于不同细胞类型的环境和内在因素的突变负荷不是 知道的此外，还不知道DNA修复基因内的多态性如何损害修复效率， 改变暴露于环境DNA损伤的细胞以及未暴露的细胞中的突变景观。 这项建议的目的是确定体细胞基因组变化的程度在体内和不同的 个体，并检查有助于这种变异性的机制。为了实现这一目标，我将 探索以下目标。在Aim 1中，我将直接分析DNA修复多态性的影响， 与癌症的DNA修复能力的关系。使用基于质粒的宿主细胞再活化 通过检测，我将测试具有纯合次要（突变型）或主要（野生型）等位基因的淋巴细胞的修复效率。 我还将确定这些突变的人类基因是否会增加酵母中的突变和重组率， 在暴露于外源性DNA损伤和在未受挑战的生长期间的人细胞中。在AIM 2中，我将 确定有害的单核苷酸多态性（SNP）在DNA修复基因中的作用。突变 导致功能性MBD 4糖基化酶的丧失，已显示增加CpG中的C-3 T变化 癌症基因组中的二核苷酸。我将测试预测对MBD 4蛋白有害的SNP 也增加突变负荷和改变健康个体体细胞中的特征。在AIM 3中，我将 估计从不同身体部位的相同个体分离的不同细胞类型中的突变负荷。我会 评估与已知的环境和内源性基因相关的突变特征的贡献 诱变源与样品中的突变负荷之间的关系。本建议中的研究完成后， 为我提供细胞培养、人类细胞系遗传操作和生物信息学方面的专业知识， 作为一名独立研究人员的成功职业之路。 意义：这些研究将增加我们对环境和遗传相互作用的理解。 决定体细胞诱变的因素。这些结果对于理解 个体对癌症和其他与体细胞诱变有关的疾病的影响，以及在设计个体- 具体的疾病预防策略。