Dissecting the Role Ubiquitin E3 Ligase UBR5 in Lymphomagenesis

剖析泛素 E3 连接酶 UBR5 在淋巴瘤发生中的作用

• 批准号: 10276282
• 负责人: Shannon Buckley
• 金额: $ 38.53万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10276282
• 关键词: Alleles; Alternative Splicing; Antibodies; B-Cell Activation; B-Cell Development; B-Cell Neoplasm; B-Cell NonHodgkins Lymphoma; B-Lymphocyte Subsets; B-Lymphocytes; Blood; C-terminal; CRISPR/Cas technology; Catalytic Domain; Cell Cycle; Cell Maturation; Cell physiology; Cells; Complex; Cysteine; DNA Damage; Data; Defect; Development; Disease; Disease Progression; Evolution; Frameshift Mutation; Future; Genes; Genetic; Genetic Transcription; Goals; Lead; Length; Lymphoid; Lymphoma; Lymphoma cell; Lymphomagenesis; Malignant Neoplasms; Mantle Cell Lymphoma; Mantle Zone; Messenger RNA; Modeling; Molecular; Mus; Mutant Strains Mice; Mutate; Mutation; Non-Hodgkin' s Lymphoma; Nonsense Codon; Pathogenesis; Pathway interactions; Patients; Phenotype; Plasma Cells; Population; Protein Splicing; Proteins; Proteomics; Publishing; RNA Splicing; Role; Sampling; Signal Transduction; Spleen; Spliceosomes; Structure of germinal center of lymph node; Survival Rate; System; Technology; Testing; Therapeutic; Therapeutic Agents; Therapeutic Intervention; Ubiquitin; Up-Regulation; base; cohort; conditional mutant; drug discovery; effective therapy; functional disability; insight; knock-down; lymph nodes; migration; mouse model; multicatalytic endopeptidase complex; mutant; new therapeutic target; next generation sequencing; novel; overexpression; protein degradation; protein expression; scaffold; therapeutic target; tool; tumor; ubiquitin-protein ligase

ABSTRACT Mantle cell lymphoma (MCL) is a rare and aggressive non-Hodgkin’s lymphoma. Unfortunately limited therapies for MCL are currently available suggesting a need to further unravel molecular mechanisms regulating transformation and progression of the disease. The majority of MCL patients have a t(11;14) translocation leading to overexpression of CyclinD1 resulting in extensive proliferation and block in differentiation originating in the mantle zone of the lymph node, however additional mutations are necessary for transformation. Next generation sequencing has identified a number of novel mutations in MCL patients including the ubiquitin E3 ligase UBR5. E3 ubiquitin ligases serve as the substrate-recognizing component for protein degradation by the ubiquitin proteasome system. In a cohort of 196 MCL patients UBR5 was the 3rd most frequently mutated gene and ~60% of the mutations were found within the HECT domain of UBR5, which can accept and transfer ubiquitin molecules to the substrate. In order to understand the role of UBR5 HECT domain in B-lymphoid development we generated a conditional mouse using novel CRISPR/Cas 9 technology. Loss of the HECT domain leads to a block in pre-germinal center B cells in the spleen with a reduction of both B1 and marginal B cell subsets. In addition, follicular B cells in the spleen are phenotypically abnormal and fail to terminally differentiate to anti-body secreting plasma cells. Proteomic studies reveal up-regulation of proteins associated with mRNA splicing via the spliceosome in B cells lacking the HECT domain of UBR5. These studies suggest that 1) cooperation of UBR5 mutations along with expression of cyclinD1 may led to disease progression of mantle cell lymphoma (Aim 1), 2) understanding molecular mechanism of UBR5 mutations could provide potential therapeutic targets in MCL (Aim 2), and 3) aberrant expression of U5 spliceosome proteins block B cell maturation and promote lymphomagenesis (Aim 3). In this application we propose studies to understand the role of UBR5 and its interacting proteins in B-cell lymphomagenesis and define molecular pathways regulated by UBR5 in B-cells. Our goal of the proposed studies is to provide insights to mantle cell lymphoma transformation, progression and potential future therapeutics targets.

抽象的 套细胞淋巴瘤（MCL）是一种罕见的侵袭性非霍奇金淋巴瘤。不幸的是有限 目前已有针对 MCL 的治疗方法，这表明需要进一步阐明分子机制 调节疾病的转化和进展。大多数 MCL 患者有 t(11;14) 易位导致 CyclinD1 过度表达，导致广泛增殖并阻断 分化起源于淋巴结的套区，但是需要额外的突变 转变。下一代测序已在 MCL 患者中发现了许多新突变 包括泛素 E3 连接酶 UBR5。 E3 泛素连接酶作为底物识别组件 泛素蛋白酶体系统对蛋白质的降解。在 196 名 MCL 患者的队列中，UBR5 排名第三 最常见的突变基因，约 60% 的突变是在 UBR5 的 HECT 结构域内发现的，这 可以接受泛素分子并将其转移到底物上。为了了解UBR5 HECT的作用 我们利用新型 CRISPR/Cas 9 技术生成了一只有条件的小鼠。 HECT 结构域的缺失会导致脾脏中生发前中心 B 细胞受阻，同时减少 B1 和边缘 B 细胞亚群。此外，脾脏中的滤泡 B 细胞表型异常且衰竭 最终分化为分泌抗体的浆细胞。蛋白质组学研究揭示蛋白质的上调 与缺乏 UBR5 HECT 结构域的 B 细胞中的剪接体的 mRNA 剪接相关。这些 研究表明 1) UBR5 突变与 cyclinD1 表达的协同作用可能导致疾病 套细胞淋巴瘤的进展（目标 1）、2）了解 UBR5 突变的分子机制 可以为 MCL 提供潜在的治疗靶点（目标 2）和 3）U5 剪接体的异常表达 蛋白质阻碍 B 细胞成熟并促进淋巴瘤发生（目标 3）。在此应用中，我们提出研究 了解 UBR5 及其相互作用蛋白在 B 细胞淋巴瘤发生中的作用并定义分子 B 细胞中 UBR5 调节的途径。我们拟议研究的目标是提供对套细胞的见解 淋巴瘤转化、进展和潜在的未来治疗目标。