Studies of Chemically Labile Alkylation Damage in DNA

DNA 中化学不稳定烷基化损伤的研究

基本信息

批准号：
10769108
负责人：
Seongmin Lee
金额：
$ 22.69万
依托单位：
UNIVERSITY OF TEXAS AT AUSTIN
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-15 至 2023-08-11
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10769108
关键词：
Acridines Affect Aflatoxin B1 Alkylating Agents Alkylation Antineoplastic Agents Base Excision Repairs Base Pairing Biochemical Biological Bypass Candidate Disease Gene Carcinogens Cells Charge Chemicals Chemistry Complex DNA DNA Alkylation DNA Damage DNA Modification Process DNA Structure DNA biosynthesis DNA glycosylase DNA-Directed DNA Polymerase Depurination Development Dissociation Electrophoresis Electrophoretic Mobility Shift Assay Equilibrium Etiology Excision Fluorine Frequencies Genes Genetic Transcription Goals Guanine Heterogeneity Hour Human Imidazole In Vitro Induced Mutation Isomerism Ketones Kinetics Knowledge Lesion Light Malignant Neoplasms Mechlorethamine Mediating Modification Molecular Conformation Mustard Mutagenesis Mutagens Mutation Nicotine Nitrosamines Nucleosides Nucleotides Pharmaceutical Preparations Phase Plasmids Process Property Public Health Quinones Relaxation Reporter Reporting Research Role Secondary Lesion Site Solid Structure System Technology Tobacco Uracil X-Ray Crystallography adduct antitumor agent base carcinogenesis endonuclease enol erythritol anhydride genotoxicity in vivo innovation insight intercalation ionization knock-down leinamycin mutation assay nucleotide metabolism prevent programs repair enzyme repair model repaired structural biology styrene oxide success synthetic construct tautomer three dimensional structure tool

Acridines Affect Aflatoxin B1 Alkylating Agents Alkylation Antineoplastic Agents Base Excision Repairs Base Pairing Biochemical Biological Bypass Candidate Disease Gene Carcinogens Cells Charge Chemicals Chemistry Complex DNA DNA Alkylation DNA Damage DNA Modification Process DNA Structure DNA biosynthesis DNA glycosylase DNA-Directed DNA Polymerase Depurination Development Dissociation Electrophoresis Electrophoretic Mobility Shift Assay Equilibrium Etiology Excision Fluorine Frequencies Genes Genetic Transcription Goals Guanine Heterogeneity Hour Human Imidazole In Vitro Induced Mutation Isomerism Ketones Kinetics Knowledge Lesion Light Malignant Neoplasms Mechlorethamine Mediating Modification Molecular Conformation Mustard Mutagenesis Mutagens Mutation Nicotine Nitrosamines Nucleosides Nucleotides Pharmaceutical Preparations Phase Plasmids Process Property Public Health Quinones Relaxation Reporter Reporting Research Role Secondary Lesion Site Solid Structure System Technology Tobacco Uracil X-Ray Crystallography adduct antitumor agent base carcinogenesis endonuclease enol erythritol anhydride genotoxicity in vivo innovation insight intercalation ionization knock-down leinamycin mutation assay nucleotide metabolism prevent programs repair enzyme repair model repaired structural biology styrene oxide success synthetic construct tautomer three dimensional structure tool

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项目摘要

ABSTRACT Alkylation DNA damage caused by alkylating agents promotes mutations and cancer development. Guanine N7 is targeted by a wide range of alkylating mutagens, carcinogens, and anticancer agents, producing the cationic N7-alkylguanine (N7-alkylG) adducts as major lesions. These lesions have half-lives of several hours to days in DNA and thus can affect DNA replication and transcription. The positively charged N7-alkylG lesions can also undergo further modification to generate secondary lesions such as alkyl-formamidopyrimidine (alkyl-FapyG) adducts. The recognition, repair, and mutagenesis mechanisms of many mutagen/carcinogen-induced N7- alkylG and alkyl-FapyG lesions, except for a few lesions such as N7-aflatoxin B1-G and aflatoxin B1-FapyG adducts, remain poorly characterized, thereby precluding a complete understanding of the contribution of these major lesions to mutations and cancer development. For example, the mutagenic properties of the predominant N7-alkylG adducts produced by the cancer-promoting styrene oxide are unknown. This knowledge gap has been due in part to the technical difficulty in preparing a site-specific N7-alkylG- and alkyl-FapyG-containing DNA, which is ascribed to the rapid depurination of N7-alkylG nucleosides and the facile isomerization of alkyl- FapyG during solid-phase DNA synthesis. To overcome the stability issue of N7-alkylG nucleosides, we have developed a 2’-fluorine technology that prevents spontaneous depurination by increasing the stability of N7- alkylG nucleosides. To solve the isomerization problem of alkyl-FapyG, we have taken a post-synthetic approach that produces alkyl-FapyG-containing DNA from N7-alkylG-containing DNA. Our preliminary studies show that guanine N7 alkylation can influence base-pairing properties by facilitating the formation of the rare enol tautomer, syn base conformation, and/or intercalation. Our central hypothesis is that N7-alkylG and alkyl- FapyG adducts promote mutations and cancer development by altering the base-pairing properties of the damaged guanine. Our long-term research goal is to elucidate the biological impacts of chemically labile alkylation damages and their secondary lesions using innovative approaches such as the 2’-F chemistry, the polβ host-guest-complex system, and post-synthetic DNA modification. The objective is to dissect the biological consequences of N7-alkylG and alkyl-FapyG lesions induced by potent alkylating mutagens and anticancer agents such as styrene oxide and nitrogen mustards. To accomplish this objective, we will characterize the base- pairing properties and the recognition, mutagenesis, and repair mechanisms of N7-alkylG and alkyl-FapyG adducts using combined tools of synthetic, biochemical, structural biology, and cellular approaches. The successful execution of the proposed programs will greatly advance our knowledge of the impact of carcinogen/drug-induced N7-alkylG and alkyl-FapyG lesions on the base pair conformation, tautomerism, mutagenesis, recognition, and repair, thereby providing important insights into the alkylation damage-induced mutations and cancer development.

抽象的由烷基化剂引起的烷基化DNA损伤促进突变和癌症的发展。 Guanine N7 由多种烷基化诱变剂，致癌物和抗癌剂的靶向，产生阳离子 N7-烷基鸟嘌呤（N7-烷基）加合物作为主要病变。这些病变有几个小时到几天的半衰期 DNA，因此会影响DNA的复制和转录。带正电的N7-烷基病变也可以进行进一步的修饰，以产生二级病变，例如烷基形成酰胺酰亚胺（烷基 - 抗血症）加合物。许多诱变的N7-的识别，修复和诱变机制烷基基和烷基 - 酸性病变，除了一些病变，例如N7-Aflatoxin B1-G和黄曲霉毒素B1-FAPYG 加合物的特征性不佳，从而完全理解这些贡献突变和癌症发展的主要病变。例如，主要的诱变特性由癌症苯乙烯氧化苯乙烯产生的N7-烷基加合物尚不清楚。这个知识差距有我们应部分归因于准备特定地点的N7-烷基和烷基 - 抗毒素的技术困难 DNA被分配给N7-烷基核苷的快速部署和烷基的易于异构化固相DNA合成过程中的FAPAPY。为了克服N7-烷基核酶的稳定问题，我们已经有开发了一种2'-氟化技术，该技术通过提高N7-的稳定性来防止赞助部署烷基核酶。为了解决烷基 - 酸性的异构化问题，我们采取了合成后产生来自含N7-烷基DNA的含烷基饮食的DNA的方法。我们的初步研究证明鸟嘌呤N7烷基化可以通过促进罕见的形成来影响碱基配对特性烯醇互变异物，SYN碱基构象和/或插入。我们的中心假设是N7-烷基和烷基 Fapyg加合物通过改变受损的鸟嘌呤。我们的长期研究目标是阐明化学不稳定的生物学影响烷基化损伤及其二级病变，使用2'-F化学等创新方法 POLβ宿主 - 周期复合系统和合成后DNA修饰。目的是剖析生物学由潜在烷基化诱变剂和抗癌引起的N7-烷基和烷基 - 脂肪治疗的后果苯乙烯氧化苯乙烯和氮芥末等药物。为了实现这一目标，我们将表征基础 N7-烷基和烷基-FAPYG的配对特性以及识别，诱变和修复机制使用合成，生化，结构生物学和细胞方法的合并工具的加合物。这成功执行拟议程序将大大提高我们对影响的知识致癌物/药物诱导的N7-烷基和烷基 - 抗毒性病变，依基对互变异构象，互变异构，诱变，识别和修复，从而为烷基化损伤引起的重要见解提供突变和癌症发展。