DNA DAMAGE REPAIR BY MUTYH AND MUTYH VARIANTS ASSOCIATED WITH COLORECTAL CANCER

MUTYH 和 MUTYH 变体与结直肠癌相关的 DNA 损伤修复

• 批准号: 9187801
• 负责人: SHEILA Sue DAVID
• 金额: $ 24.38万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-01 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9187801
• 关键词: 2' -deoxyadenosine; APC gene; APC2 gene; Adenine; Affinity; Alkylating Agents; Alkylation; Applications Grants; Base Excision Repairs; Binding; Binding Sites; Biological Assay; Cancer Etiology; Cells; Cellular Assay; Clinical; Clinical Data; Colorectal; Colorectal Cancer; Complex; Computer-Assisted Image Analysis; DNA; DNA Damage; DNA Repair; DNA Repair Pathway; Defect; Deoxyguanosine; Detection; Disease; Enzymatic Biochemistry; Enzymes; Escherichia coli; Excision; Functional disorder; Grant; High Pressure Liquid Chromatography; Individual; Inherited; Kinetics; Knowledge; Laboratories; Lead; Link; Malignant Neoplasms; Mammalian Cell; Mediating; Methods; Modification; Molecular; Monitor; Mutation; Nucleic Acids; Oligonucleotides; Oxidative Stress; Play; Polymorph; Positioning Attribute; Predisposition; Process; Property; Proteins; Reaction; Reporter; Role; Signal Transduction; Site; Syndrome; Techniques; Testing; Toxic effect; Translating; Tumor Suppressor Genes; Tumor Suppressor Proteins; Variant; Work; Zinc; adduct; amino group; analog; base; cancer cell; cancer therapy; carcinogenesis; early onset; experimental study; inhibitor/antagonist; insight; novel; novel therapeutic intervention; oxidative DNA damage; oxidative damage; polyposis; prevent; public health relevance; repaired; response; single molecule; tumorigenesis

 DESCRIPTION (provided by applicant): The MUTYH glycosylase has garnered the spotlight with the discovery of a correlation between inherited MUTYH variations and colorectal cancer (CRC). Using pre-steady kinetics and noncleavable 2'- deoxyadenosine analogue-containing oligonucleotides, we provided information on the functional defects of two missense variants of MUTYH found in colorectal cancer that was key for establishing the connection between MUTYH variants and colorectal cancer (now referred to a MUTYH-associated polyposis or MAP). MUTYH prevents mutations associated with 8-oxo-7,8-dihydro-2'-deoxyguanosine (OG) by removal of misincorporated adenine residues from OG:A mismatches, and thus aberrant functioning MUTYH leads to the accumulation of mutations in tumor suppressor genes, like APC. Since the original discovery of MAP, over 100 different variants of MUTYH have been discovered. Our laboratory has focused on revealing fundamental features of MUTYH and MUTYH variants. Our underlying hypothesis is that a detailed molecular understanding of OG:A mismatch recognition goes hand-in-hand with revealing intricacies of the relationship between MUTYH and colorectal cancer. We have recently developed mammalian cell assays that we will use to evaluate the repair of modified substrates in cells. This will allow us to gauge how catalytic and binding defects impact overall repair in cells. We have recent results with the bacterial enzymes that suggests that the 2-amino- group of OG is critical for initial localization f OG, and we will further test this hypothesis by making additional derivatives and directly monitoring the search process using single-molecule techniques. This will provide important information into features that are involved in the initial damage detection step, and allow for better prediction of features that made compromise damage detection. We also will use our enzymatic assays in conjunction with cellular assays to provide insight into the role of the interdomain connector (IDC) region, and the Zn(II) coordination site we recently discovered on mediating efficient repair, and coordinating with downstream repair proteins, and proteins involved in damage signaling. Lastly, we also will elaborate on work that implicated MUTYH activity in increasing the sensitivity of cells to alkylation damage. As part of this work, we will develop novel methods to tag sites of MutY glycosylase activity in cells. The significance of this work is that it will provide important information as to the how MUTYH dysfunction, either inherited or acquired, may set the stage for carcinogenesis. In addition, the role of MUTYH in mediating cellular responses to oxidative damage and alkylation may provide new strategies to target cancer cells.

 描述（由申请人提供）：随着遗传性 MUTYH 变异与结直肠癌 (CRC) 之间相关性的发现，MUTYH 糖基化酶引起了人们的关注。利用前稳态动力学和含有不可裂解的 2'-脱氧腺苷类似物的寡核苷酸，我们提供了有关结直肠癌中发现的 MUTYH 两种错义变体功能缺陷的信息，这对于建立 MUTYH 变体和结直肠癌（现在称为 MUTYH 相关息肉病或 MAP）之间的联系至关重要。 MUTYH 通过去除 OG:A 错配中错误掺入的腺嘌呤残基来防止与 8-oxo-7,8-diHydro-2'-deoxyguanosine (OG) 相关的突变，因此功能异常的 MUTYH 会导致肿瘤抑制基因（如 APC）突变的积累。自最初发现 MAP 以来，已发现 MUTYH 的 100 多种不同变体。我们的实验室致力于揭示 MUTYH 和 MUTYH 变体的基本特征。我们的基本假设是，对 OG:A 错配识别的详细分子理解与揭示 MUTYH 和结直肠癌之间错综复杂的关系密切相关。我们最近开发了哺乳动物细胞测定法，我们将用它来评估细胞中修饰底物的修复。这将使我们能够衡量催化和结合缺陷如何影响细胞的整体修复。我们最近的细菌酶结果表明 OG 的 2-氨基对于 OG 的初始定位至关重要，我们将通过制作额外的导数并使用单分子技术直接监测搜索过程来进一步测试这一假设。这将为初始损坏检测步骤中涉及的特征提供重要信息，并允许更好地预测损害检测的特征。我们还将使用我们的酶测定与细胞测定相结合，深入了解域间连接器 (IDC) 区域和我们最近发现的 Zn(II) 协调位点在介导有效修复、与下游修复蛋白和参与损伤信号转导的蛋白质协调方面的作用。最后，我们还将详细阐述涉及 MUTYH 活性增加细胞对烷基化损伤敏感性的工作。作为这项工作的一部分，我们将 开发新方法来标记细胞中 MutY 糖基化酶活性位点。这项工作的意义在于，它将提供有关 MUTYH 功能障碍（无论是遗传性还是后天性）如何为致癌奠定基础的重要信息。此外，MUTYH 在介导细胞对氧化损伤和烷基化反应中的作用可能为靶向癌细胞提供新的策略。