The role of AID/APOBEC3 proteins in genome instability in multiple myeloma

AID/APOBEC3 蛋白在多发性骨髓瘤基因组不稳定中的作用

• 批准号: 9925834
• 负责人: David G. Schatz
• 金额: $ 40.66万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-15 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9925834
• 关键词: Aneuploidy; Antigens; Automobile Driving; B lymphoid malignancy; B-Cell Activation; B-Lymphocytes; Biochemical; Biological Models; Bone Marrow; Cell Line; Cells; Chromosomal translocation; Chromosome Deletion; Chromosome abnormality; Chronic; Clonal Evolution; Collaborations; Cytidine Deaminase; Cytosine; DNA; DNA Damage; DNA Double Strand Break; DNA Sequence Alteration; DNA strand break; Data; Deaminase; Detection; Development; Disease; Disease Progression; Enzymes; Evolution; Exhibits; Family; Family member; Gaucher Disease; Generations; Genes; Genome; Genomic Instability; Genomics; Goals; IGH@ gene cluster; Immunoglobulin Class Switching; Immunoglobulin Genes; Immunoglobulin Somatic Hypermutation; Immunoglobulin Switch Recombination; Immunoglobulins; Incidence; Individual; Inflammatory; Knock-out; Lead; Left; Link; Lipids; Malignant - descriptor; Malignant Neoplasms; Measures; Mediating; Modeling; Molecular; Monoclonal Gammapathies; Multiple Myeloma; Mus; Mutate; Mutation; Nuclear; Outcome; Pathogenesis; Pathway interactions; Patients; Plasma Cells; Play; Primary Neoplasm; Proteins; Role; Series; Single-Stranded DNA; Site; Somatic Mutation; Source; System; Testing; Uracil; Work; activation-induced cytidine deaminase; antiviral immunity; base; cancer genome; cancer type; design; experimental study; gammopathy; genetic information; genome sequencing; genomic aberrations; genotoxicity; humanized mouse; immune activation; in vivo; inducible gene expression; insight; knock-down; malignant breast neoplasm; mouse model; neoplastic cell; novel; outcome forecast; premalignant; prevent; tumor

SUMMARY Multiple Myeloma (MM) is a malignancy of bone marrow plasma cells preceded by a series of premalignant and transitional stages. Cells at all stages exhibit significant genomic aberrations, the sources of which are not well understood. This has left a major gap in our understanding of the mechanisms that drive MM initiation and progression, a gap that this proposal is designed to fill. Recent evidence suggests that cytidine deaminases—enzymes that convert cytosine to uracil in DNA—are important culprits in genomic instability in MM. One important example is the activation induced deaminase, AID, which initiates somatic hypermutation and class switch recombination but which also mutates many regions of the B cell genome and causes translocations similar to those found in MM. The related APOBEC3 family of cytidine deaminases can also mutate DNA, and numerous findings link AID and APOBEC3 enzymes to genome instability and mutations in MM. Our preliminary data demonstrate that MM cells express APOBEC3B, C, D, F and G, with APOBEC3B being expressed particularly strongly. Interestingly, APOBEC3B has recently been implicated in genome instability in breast cancer. We further find that expression of AID and certain APOBEC3 enzymes increases levels of DNA strand breaks in MM cells. Based on this, we hypothesize that AID and APOBEC3 family enzymes are a major cause of genomic aberrations and disease progression in MM. Recent findings provide a strong link between lipid disregulation, immune activation, and MM, with as much as a third of the clonal gammopathies found in MM patients reacting to lipids. Hence, an important overall guiding hypothesis of our work is that chronic B cell activation arising from elevated levels of inflammatory lipids contributes to increased activity of AID/APOBEC3 and MM disease progression. We systematically test these hypotheses in three Aims. In Aim 1, we determine the extent to which AID/APOBEC3 enzymes, alone and in concert, contribute to biochemical and molecular measures of nuclear deaminase activity and genomic damage. In Aim 2, we determine how these deaminases are regulated, revealing those regions of the MM genome that are susceptible to mutation, DNA breaks, and translocations due to their action. Finally, in Aim 3 we use established and novel mouse model systems and MM and its premalignant stage propagated in humanized mice to assess the in vivo effects of inflammatory lipids on the expression/activity of AID/APOBEC3 factors, DNA damage and mutation of the MM genome, and clonal evolution of MM. Together, the proposed experiments will provide a comprehensive picture of the activity, targeting, and outcome of cytidine deaminase action in MM, with broad implications for disease pathogenesis.

概括 多发性骨髓瘤（MM）是骨髓浆细胞的恶性肿瘤 和过渡阶段。细胞在所有阶段都暴露了明显的基因组畸变，其来源是 不太了解。这在我们对驱动MM的机制的理解上留下了一个重大差距 启动和进步，该提案旨在填补的差距。最近的证据表明 胞苷死亡酶 - 将胞嘧啶转化为DNA中尿嘧啶的酶是基因组重要的罪魁祸首 MM的不稳定性。一个重要的例子是激活诱导的脱氨酶AID，启动体细胞 超代和类开关重组，但也突变了B细胞基因组的许多区域 并导致易位类似于MM中的易位。相关的APOBEC3胞苷家族 脱氨酶还可以突变DNA，许多发现将AID和APOBEC3酶与基因组联系起来 MM中的不稳定性和突变。我们的初步数据表明，MM细胞表达APOBEC3B，C， d，f和g，apobec3b的表达特别强烈。有趣的是，apobec3b最近有 我们在乳腺癌的基因组不稳定性中隐含。我们进一步发现援助的表达和确定 APOBEC3酶增加了MM细胞中DNA链断裂的水平。基于此，我们假设 该辅助和APOBEC3家族酶是基因组畸变和疾病进展的主要原因 在毫米中。最近的发现提供了与脂质脱离，免疫激活和MM之间的密切联系， 在MM患者中发现的克隆胶质病的三分之一，对脂质反应。因此，重要的是 我们工作的总体指导假设是，慢性B细胞激活升高。 炎性脂质有助于增加AID/APOBEC3和MM疾病进展的活动。我们 在三个目标中系统地检验这些假设。在AIM 1中，我们确定了多大程度 AID/APOBEC3酶，单独且共同协调一致，有助于生化和分子测量 核脱氨酶活性和基因组损伤。在AIM 2中，我们确定这些脱氨酶是如何的 调节，揭示了易受突变，DNA断裂和的MM基因组区域 由于其行动而引起的易位。最后，在AIM 3中，我们使用已建立的新型鼠标模型系统 和MM及其前态阶段在人源化小鼠中传播，以评估体内影响 关于AID/APOBEC3因子的表达/活性的炎性脂质，DNA损伤和突变 MM基因组和MM的克隆进化。拟议的实验一起将提供 MM中细胞丁胺死亡酶作用的活动，靶向和结果的全面图景， 对疾病发病机理的广泛影响。