PROJECT 3

项目3

基本信息

批准号：
10225391
负责人：
Hideki Aihara
金额：
$ 32.03万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-09 至 2022-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10225391
关键词：
2&apos -Deoxythymidine APOBEC3F gene Achievement Active Sites Address Adjuvant Affinity Binding Biological Assay C-terminal CCL21 gene Cancer Etiology Catalytic Domain Cells Chemicals Clinical Closure by clamp Complex Computer Models Crystallization Cytosine DNA DNA Binding DNA Damage DNA Repair DNA Sequence DNA biosynthesis Data Deaminase Deamination Deoxycytidine Development Diagnosis Dinucleoside Phosphates Disease Drug resistance Enzymes Estrogen receptor positive Evolution Family Family member Foundations Future GTP-Binding Protein alpha Subunits, Gs Genome Genomics Goals Histidine Human In Vitro Innate Immune Response Knowledge Length Life Malignant Neoplasms Mediating Molecular Molecular Chaperones Molecular Conformation Monoclonal Antibodies Mutagenesis Mutation N-terminal Neoplasm Metastasis Outcome Pathogenicity Patient-Focused Outcomes Positioning Attribute Process Protein Engineering Proteins Publishing RNA Research Residual state Resistance Resolution Roentgen Rays Role Single-Stranded DNA Solid Source Specificity Structure System Tamoxifen Testing Thymine Uracil Variant Vertebral column Virus Work activation-induced cytidine deaminase analog apoB mRNA editing catalytic subunit base cancer therapy drug development ds-DNA genetic regulatory protein improved in vivo inhibitor/antagonist malignant breast neoplasm member mouse model novel nucleobase overexpression preference prevent programs structural biology therapeutic target therapy outcome tumor tumor heterogeneity

项目摘要

PROJECT 3 – STRUCTURAL BIOLOGY OF DNA DEAMINASES IN BREAST CANCER ABSTRACT The hallmark activity of the APOBEC family of enzymes is deamination of cytosines to uracils (C-to-U) in single-stranded (ss)DNA. This editing activity normally functions in the innate immune response by contributing to virus and transposon restriction. However, recent studies by our labs and many others strongly indicate that APOBEC3B (A3B) is a major source of genomic mutations that drive the progression of multiple human cancers and the development of drug resistance. This finding – that a cellular enzyme actively introduces mutations in cancer – is in stark contrast to a more conventional view, in which mutations in cancer are caused by DNA damage from exogenous sources or errors introduced during DNA replication or repair. Because A3B is not an essential enzyme for life, it is a promising target for anti-cancer therapies. Thus, our Program's overarching hypothesis is that A3B inhibition, as an adjuvant to primary treatment options, will help to prevent detrimental mutation-driven outcomes such as drug resistance and metastasis. However, despite its strong relevance to cancer as a potential therapeutic target, it is not fully known how A3B engages ssDNA substrates, how it achieves high selectivity for ssDNA over RNA, or how its DNA deaminase activity is regulated in cells. Moreover, it is not known how related enzymes such as APOBEC3H (A3H) and APOBEC3F (A3F) with different compositions of ssDNA-binding residues engage similar target sequences. In Project 3, we have started to address these issues by solving multiple A3B catalytic domain crystal structures and, recently, achieving co-crystal structures of ssDNA bound to a variant of the A3B catalytic domain as well as to the related enzyme APOBEC3A (A3A). Aim 1 will build on this knowledge to further delineate the global ssDNA binding mechanism of A3B and A3H. Aim 2 will examine the local dinucleotide targeting mechanism and possible modes of inhibition of the APOBEC family of enzymes. Our goals are to gain deeper mechanistic understandings of the pathogenic APOBEC-mediated ssDNA cytosine deamination process and to establish a solid foundation for future development of APOBEC inhibitors for cancer therapies. These studies will propel our Program toward achieving its long-term goal of inhibiting APOBEC mutagenesis in breast cancer, thereby slowing tumor evolution and improving overall therapeutic outcomes for patients.

项目 3 – 乳腺癌 DNA 脱氨酶的结构生物学抽象的 APOBEC 酶家族的标志性活性是胞嘧啶脱氨基为尿嘧啶（C-to-U）单链 (ss)DNA。这种编辑活动通常通过促进先天免疫反应发挥作用。然而，我们实验室和许多其他实验室最近的研究强烈表明这一点。 APOBEC3B (A3B) 是驱动多种人类疾病进展的基因组突变的主要来源癌症和耐药性的发展这一发现——细胞酶主动引入。癌症突变——与癌症突变引起的更传统观点形成鲜明对比由外源性 DNA 损伤或 DNA 复制或修复过程中引入的错误引起。不是生命必需的酶，但它是抗癌治疗的一个有前途的目标。总体假设是 A3B 抑制作为主要治疗方案的辅助手段，将有助于预防然而，尽管其强大，但突变驱动的结果如耐药性和转移。与癌症作为潜在治疗靶点的相关性，目前尚不完全清楚 A3B 如何与 ssDNA 底物结合，它如何实现对 ssDNA 相对于 RNA 的高选择性，或者如何在细胞中调节其 DNA 脱氨酶活性。此外，尚不清楚 APOBEC3H (A3H) 和 APOBEC3F (A3F) 等酶与在项目 3 中，我们有不同的 ssDNA 结合残基组合物与相似的靶序列结合。开始通过解决多个 A3B 催化域晶体结构来解决这些问题，最近，实现 ssDNA 与 A3B 催化结构域变体以及相关酶 APOBEC3A (A3A) 的目标 1 将以此知识为基础，进一步描绘全球 ssDNA。 A3B 和 A3H 的结合机制目标 2 将检查局部二核苷酸靶向机制和 APOBEC 酶家族的可能抑制模式我们的目标是获得更深入的机制。了解致病性 APOBEC 介导的 ssDNA 胞嘧啶脱氨基过程并建立一个这些研究将为未来开发用于癌症治疗的 APOBEC 抑制剂奠定坚实的基础。我们的计划旨在实现抑制乳腺癌 APOBEC 突变的长期目标，从而减缓肿瘤演变并改善患者的整体治疗结果。