Eukaryotic DNA Alkylation Repair

真核DNA烷基化修复

基本信息

批准号：
9262928
负责人：
LEONA D. SAMSON
金额：
$ 33.76万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-06-10 至 2018-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9262928
关键词：
20 year old Alkylating Agents Alkylation Animals Base Excision Repairs Biochemical Biological Assay Cancer Patient Cell Differentiation process Cell Lineage Cell Survival Cells Chemicals Chemotherapy-Oncologic Procedure Clinic Common Lymphoid Progenitor Cytoplasmic Granules Cytotoxic agent DNA DNA Alkylation DNA Damage DNA Repair DNA Repair Enzymes DNA Repair Pathway DNA glycosylase Disease Environment Eukaryotic Cell Exposure to Funding Genetic Materials Genomic approach Goals Grant Health Hematopoietic Hematopoietic stem cells Human In Vitro Intuition Knockout Mice Learning Left 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 Research Resistance Retinal Photoreceptors Role Small Interfering RNA Stem cells Teratogens Testing Tissues Ultraviolet Rays Yeasts adult stem cell cancer therapy carcinogenicity cell type cytotoxic deep sequencing embryonic stem cell genetic makeup granule cell granulocyte improved in vivo interest killings macrophage nanoparticle neoplastic cell novel prevent progenitor public health relevance repair enzyme repaired response tissue degeneration trait

项目摘要

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）：这是一份竞争性更新申请的重新提交，旨在延续二十多年的真核细胞 DNA 烷基化修复研究项目。我们建议探索一种特定的 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；又名 MPg/MPG 和 Apng/APNG）启动的碱基切除修复 (BER)，如何有助于响应暴露于 DNA 损伤剂后的不同细胞类型。烷化剂具有细胞毒性、致突变性、致畸性、致畸性和致癌性，它们是我们环境中最有效、最丰富的化学 DNA 损伤剂之一。此外，烷化剂作为正常细胞代谢物存在于细胞内，并且是氧化应激的副产物。此外，一些毒性最强的烷化剂通常用于癌症患者的化疗。在过去的资助期间，我们了解到的最重要的事情之一（除了确定了一些涉及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，Aag DNA 修复酶的表达，即使是在野生型中水平，具有反直觉的后果，使这些细胞对 DNA 烷基化损伤的细胞毒性作用极其敏感。在下一个资助期间，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得 Aag 启动的 DNA 修复对细胞存活如此不利。这将通过追求以下四个具体目标来实现：目标 1、2 和 3 将利用干细胞/再生医学领域的最新进展，将小鼠胚胎干 (ES) 细胞体外分化为特异性分化的造血骨髓细胞，视网膜感光细胞和小脑颗粒细胞，所有这些细胞在体内都表现出 Aag 依赖性烷基化敏感性，这与它们的 ES 细胞祖细胞表现出 Aag 依赖性烷基化不同反抗。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和分化细胞。所有细胞类型都将测试其对两种不同烷化剂和一种非烷化剂（紫外线）的敏感性。通过分离和表征（目标 4）这些同基因细胞的表型已从 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（骨髓细胞、感光细胞和颗粒神经元细胞），我们希望了解如何更好地预测细胞和人将如何反应烷化剂普遍存在于环境中，并常用于临床。拟议项目与健康的相关性在于，所获得的信息将有助于进一步推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，尤其是癌症的临床治疗方式。