Eukaryotic DNA Alkylation Repair

真核DNA烷基化修复

• 批准号: 8499778
• 负责人: LEONA D. SAMSON
• 金额: $ 33.99万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-10 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8499778
• 关键词: 20 year old; 3-methyladenine-DNA glycosylase; Alkylating Agents; Alkylation; Animals; Base Excision Repairs; Biochemical; Biological Assay; Cancer Patient; Cell Lineage; Cell Survival; Cells; Chemicals; Chemotherapy-Oncologic Procedure; Clinic; Common Lymphoid Progenitor; Cytoplasmic Granules; DNA; DNA Alkylation; DNA Damage; DNA Repair; DNA Repair Enzymes; DNA Repair Pathway; Disease; Environment; Eukaryotic Cell; Exposure to; Funding; Genetic Materials; Genomics; Goals; Grant; Health; Hematopoietic; Hematopoietic stem cells; Human; In Vitro; Knockout Mice; Learning; Left; Life; Lymphoid; Malignant Neoplasms; Mediating; Methods; Mus; Myelogenous; Myeloid Cells; Myeloid Progenitor Cells; Neurons; Normal Cell; Organism; Oxidative Stress; Pathway interactions; Phenotype; Photoreceptors; Physiological Processes; Premature aging syndrome; Regenerative Medicine; Relative (related person); Research; Resistance; Retinal Photoreceptors; Role; Small Interfering RNA; Stem cells; Testing; Tissues; Ultraviolet Rays; Yeasts; adult stem cell; cell type; cytotoxic; deep sequencing; embryonic stem cell; granule cell; granulocyte; improved; in vivo; interest; killings; macrophage; nanoparticle; neoplastic cell; novel; prevent; progenitor; public health relevance; repair enzyme; repaired; response; trait

DESCRIPTION (provided by applicant): This is a re-submission of a competitive renewal application for the continuation of a more than twenty year old project to study DNA alkylation repair in eukaryotic cells. We propose to explore how one particular DNA repair pathway, namely base excision repair (BER) initiated by the alkyladenine DNA glycosylase repair enzyme (Aag in mice, AAG in humans; a.k.a. Mpg/MPG and Apng/APNG), contributes to the response of different cell types upon exposure to DNA damaging agents. Alkylating agents are cytotoxic, mutagenic, clastogenic, teratogenic and carcinogenic, and they represent one of the most potent and abundant classes of chemical DNA damaging agents in our environment. In addition, alkylating agents are present inside cells as normal cellular metabolites, and they are produced as byproducts of oxidative stress. Moreover, some of the most toxic alkylating agents are commonly used for the chemotherapeutic treatment of cancer patients. In the past funding period one of the most important things we learned (in addition to identifying a number of new pathways involved in protecting cells against alkylating agents) is that in certain cell types, expression of the Aag DNA repair enzyme, even at wild type levels, has the counter-intuitive consequence of rendering those cells extremely sensitive to the cytotoxic effects of DNA alkylation damage. In the next funding period we will seek to understand more fully what features of these specific cell types render Aag-initiated DNA repair so detrimental to cell survival. This will be achieved by pursuing the following four Specific Aims: Aims 1, 2 and 3 will exploit recent advances in the stem cell/regenerative medicine field for the in vitro differentiatin of mouse embryonic stem (ES) cells into specifically differentiated hematopoietic myeloid cells, retinal photoreceptor cells, and cerebellar granule cells, all of which display Aag-dependent alkylation sensitivity in vivo, unlike their ES cell progenitor that displays Aag-dependent alkylation resistance. In addition, as part of Aims 1 and 3, we will directly isolate differentiatig and differentiated cells from mice. All cell types will be tested for their sensitivity to two diffrent alkylating agents, and one non-alkylating agent, ultraviolet light. By isolating and characterizing (Aim 4) these isogenic cells whose phenotype has transitioned from Aag-dependent alkylation resistance (ES cells) to Aag-dependent alkylation sensitivity (myeloid, photoreceptor and granule neuron cells) we hope to learn how to better predict how cells and people will respond to alkylating agents ubiquitously present in the environment, and commonly used in the clinic. The health relatedness of the proposed project is that the information gained will contribute to furthering our goals to prevent cancer and other DNA damage-related diseases, while also contributing to improving how those diseases, especially cancer, are treated in the clinic.

描述（由申请人提供）：这是一份重新提交的竞争性更新申请，用于继续研究真核细胞中DNA烷基化修复的20多年项目。我们建议探索一种特殊的DNA修复途径，即由烷基腺嘌呤DNA糖基化酶修复酶（小鼠中的Aag，人类中的AAG; a.k.a. Mpg/MPG和Apng/APNG），有助于不同细胞类型在暴露于DNA损伤剂时的反应。烷基化剂具有细胞毒性、致突变性、致染色体断裂性、致畸性和致癌性，并且它们代表了我们环境中最有效和最丰富的一类化学DNA损伤剂。此外，烷化剂作为正常细胞代谢物存在于细胞内，并且它们作为氧化应激的副产物产生。此外，一些毒性最大的烷化剂通常用于癌症患者的化学治疗。在过去的资助期间，我们学到的最重要的事情之一（除了确定一些参与保护细胞免受烷化剂侵害的新途径之外）是，在某些细胞类型中，即使在野生型水平下，Aag DNA修复酶的表达也会导致这些细胞对DNA烷基化损伤的细胞毒性效应非常敏感。在下一个资助期内，我们将寻求更全面地了解这些特定细胞类型的哪些特征使Aag启动的DNA修复对细胞存活如此有害。这将通过追求以下四个具体目标来实现：目的1、2和3将利用干细胞/再生医学领域最新进展，在体外将小鼠胚胎干（ES）细胞分化为特异性分化造血髓样细胞、视网膜感光细胞和小脑颗粒细胞，所有这些细胞在体内均表现出Aag依赖性烷基化敏感性，不像它们的ES祖细胞显示Aag依赖性烷基化抗性。此外，作为目标1和3的一部分，我们将直接从小鼠中分离分化细胞和分化细胞。将检测所有细胞类型对两种不同烷化剂和一种非烷化剂紫外光的敏感性。通过分离和表征 (Aim 4）这些表型已经从Aag依赖性烷基化抗性（ES细胞）转变为Aag依赖性烷基化敏感性（骨髓、光感受器和颗粒神经元细胞）的同基因细胞，我们希望了解如何更好地预测细胞和人将如何响应普遍存在于环境中并且在临床中常用的烷基化剂。拟议项目的健康相关性在于，所获得的信息将有助于促进我们预防癌症和其他DNA损伤相关疾病的目标，同时也有助于改善这些疾病，特别是癌症在临床上的治疗方式。