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: 10165658
• 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 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10165658
• 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; Prognosis; 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; 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) 是一种骨髓浆细胞的恶性肿瘤，随后发生一系列癌前病变 所有阶段的细胞都表现出显着的基因组畸变，其来源是 这使得我们对 MM 驱动机制的理解存在重大差距。 最近的证据表明，该提案旨在填补这一空白。 胞苷脱氨酶（将 DNA 中的胞嘧啶转化为尿嘧啶的酶）是基因组中的重要罪魁祸首 MM 中的一个重要例子是激活诱导的脱氨酶 AID，它启动体细胞。 超突变和类别转换重组，但也会使 B 细胞基因组的许多区域发生突变 并引起与 MM 中发现的类似的易位 相关的 APOBEC3 胞苷家族。 脱氨酶也会使 DNA 发生突变，大量研究结果将 AID 和 APOBEC3 酶与基因组联系起来 我们的初步数据表明 MM 细胞表达 APOBEC3B、C、 D、F 和 G，其中 APOBEC3B 表达特别强烈。 我们进一步发现 AID 的表达与乳腺癌的基因组不稳定有关。 APOBEC3 酶会增加 MM 细胞中 DNA 链断裂的水平。基于此，我们陷入了困境。 AID 和 APOBEC3 家族酶是基因组畸变和疾病进展的主要原因 最近的研究结果表明，脂质失调、免疫激活和 MM 之间存在密切联系。 在 MM 患者中发现的克隆性丙种球蛋白病中有多达三分之一对脂质有反应。 我们工作的总体指导假设是，慢性 B 细胞激活是由 B 细胞水平升高引起的。 炎性脂质有助于 AID/APOBEC3 活性增加和 MM 疾病进展。 显然，我们在三个目标中测试这些假设，在目标 1 中，我们确定了这些假设的程度。 AID/APOBEC3 酶单独或协同作用，有助于生物化学和分子测量 在目标 2 中，我们确定这些脱氨酶的性质。 调控，揭示 MM 基因组中那些容易发生突变、DNA 断裂和 最后，在目标 3 中，我们使用已建立的新型小鼠模型系统。 以及在人源化小鼠中传播 MM 及其癌前阶段，以评估 MM 的体内影响 炎症脂质对 AID/APOBEC3 因子表达/活性、DNA 损伤和突变的影响 MM 基因组和 MM 克隆进化一起，所提出的实验将提供一个。 胞苷脱氨酶在 MM 中的活性、靶向和结果的全面描述， 对疾病发病机制的广泛影响。