CORE D

摘要 APOBEC酶是单链DNA胞嘧啶-尿嘧啶脱氨酶，其通常保护细胞免于 病毒感染一个家族成员APOBEC3B（A3B）在超过一半的乳腺肿瘤中过表达， 它的突变特征存在于20%的原发性和50%的转移性乳腺肿瘤中。A3B过表达 和突变标记也与治疗失败和总生存率低有关。我们的节目 已经表明，抑制A3B介导的肿瘤演变有助于改善治疗结果， 雌激素受体阳性乳腺癌的小鼠模型。这些数据支持我们的计划的统一 假设A3B抑制作为主要治疗选择的辅助，将有助于防止有害的 突变驱动的结果，如耐药性和转移。我们的计划成员正在合作， 通过3个紧密结合的项目来验证这一假设，这些项目侧重于生物学，化学生物学和 A3B结构生物学这些项目由4个服务核心支持，包括核心D-酶和 抗体，其具有2个具体目标：目标1是生产重组APOBEC酶并执行 使用这些酶的标准DNA脱氨酶测定，这将使APOBEC研究标准化 跨实验室和时间。目的2：制备抗A3B及相关人类抗原的单克隆抗体 APOBEC3酶。特异性抗体的可用性将推动该计划的研究向前发展， 这对于该项目开发基于抗体的A3B诊断分析的转化目标非常重要阳性肿瘤，以便告知患者预后，并最终制定治疗计划。所产生的试剂 对于加快实现每个项目的目标，确保最大的严谨性和可重复性， 跨项目和合作实验室，推动项目合作和APOBEC研究， 更大的癌症研究社区总的来说，尽管其相对较小，但Core D是一个强大的支持 我们节目的特点。

ABSTRACT APOBEC enzymes are single-stranded DNA cytosine-to-uracil deaminases that normally protect cells from viral infections. One family member, APOBEC3B (A3B), is overexpressed in over half of all breast tumors and its mutation signature is found in 20% of primary and 50% of metastatic breast tumors. A3B overexpression and mutation signature have also been associated with therapy failure and poor overall survival. Our Program has shown that inhibition of A3B-mediated tumor evolution contributes to improved therapy outcomes in a mouse model of estrogen receptor-positive breast cancer. These data support our Program’s unifying hypothesis that A3B inhibition, as an adjuvant to primary treatment options, will help to prevent detrimental mutation-driven outcomes such as drug resistance and metastasis. Our Program members are collaborating to test this hypothesis through 3 tightly integrated Projects focusing on the biology, chemical biology, and structural biology of A3B. These Projects are supported by 4 service Cores, including Core D – Enzymes & Antibodies, which has 2 specific aims: Aim 1 is to produce recombinant APOBEC enzymes and to perform standard DNA deaminase assays with these enzymes, which will allow standardization of APOBEC studies across labs and time. Aim 2 is to develop specific monoclonal antibodies for A3B and related human APOBEC3 enzymes. The availability of specific antibodies will move the Program’s research forward and is important for the Program’s translational goal of developing an antibody-based assay for diagnosing A3Bpositive tumors in order to inform patient prognosis and, ultimately, therapeutic plans. The reagents resulting from both Aims are vital for expediting the goals of each Project, ensuring maximal rigor and reproducibility across Projects and collaborating labs and fueling Program collaborations and APOBEC research in the greater cancer research community. Overall, despite its relatively modest size, Core D is a powerful enabling feature of our Program.