Interrogating the minor spliceosome to understand and treat leukemia

研究小剪接体以了解和治疗白血病

基本信息

批准号：
10434705
负责人：
Omar Abdel-Wahab
金额：
$ 64.6万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-03 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10434705
关键词：
AKT Signaling Pathway Adaptor Signaling Protein Address Affect Amino Acids Biology Blood Cells Bone Marrow Cells Clonality Complex Cytokine Signaling DNA Data Development Dysmyelopoietic Syndromes Enzymes Event Exhibits Gene Expression Genes Genetic Guanosine Health Hematopoiesis Hematopoietic Human Introns Knockout Mice Link Malignant - descriptor Malignant Neoplasms Messenger RNA Minor Mitogen-Activated Protein Kinases Modeling Molecular Mus Mutagenesis Mutate Mutation Myeloid Leukemia Myeloproliferative disease Open Reading Frames Oxides PI3K/AKT PTEN gene Pathogenesis Patient Care Patients Pattern Physicians Process Proteins Proteome Publishing RNA RNA Degradation RNA Splicing Recurrence Role SRSF2 gene Scientist Signal Pathway Spliceosomes Therapeutic Translating Tumor Suppressor Proteins Ubiquitination Work cohort comparative conditional knockout defined contribution demethylation efficacy testing experimental study functional genomics hematopoietic stem cell self-renewal inhibitor leukemia leukemogenesis loss of function mutant novel novel therapeutic intervention novel therapeutics response self-renewal transcriptome ubiquitin ligase

项目摘要

SUMMARY Genes encoding RNA splicing factors are the most common class of mutations in patients with myelodysplastic syndromes (MDS) and are also common across all other forms of myeloid malignancies. These leukemia- associated “spliceosomal mutations” primarily occur in four genes: SF3B1, SRSF2, U2AF1, and ZRSR2. In three of these four genes (SF3B1, SRSF2, and U2AF1), the mutations occur at specific amino acid residues in a heterozygous manner (so-called “mutational hotspots”) and cause gain/alteration of function. In contrast, mutations in ZRSR2 occur throughout the open reading frame and appear to confer loss of function. Moreover, ZRSR2's normal function makes it unique amongst the commonly mutated RNA splicing factors in leukemias: ZRSR2 is the only frequently mutated factor that primarily functions in the recognition of a rare class of introns known as “minor introns.” Thus, ZRSR2 mutations are significantly enriched in leukemia and exhibit a unique genetic spectrum and function amongst recurrent spliceosomal mutations, yet they are comparatively poorly studied and understood compared to mutations in SF3B1, SRSF2, and U2AF1. Here, we propose to determine the mechanistic, functional, and therapeutic consequences of ZRSR2 mutations in leukemia. Our interdisciplinary team consists of a physician-scientist with expertise in leukemia biology and patient care (Abdel-Wahab) and a basic scientist with expertise in RNA splicing and functional genomics (Bradley). As minor introns are far more conserved than are most other introns, we hypothesize that a cross-species comparisons of the effects of ZRSR2 loss will be particularly useful for understanding how molecular alterations in splicing drive malignant transformation. In addition, we hypothesize that aberrant splicing induced by ZRSR2 loss will enable novel therapeutic approaches. In preliminary experiments, we generated a Zrsr2 conditional knockout (cKO) mouse, assembled a relevant patient cohort, characterized the transcriptomes of our Zrsr2 cKO mouse and ZRSR2-mutant MDS, and performed a functional genomic screen to model and prioritize ZRSR2-regulated splicing events. These studies revealed that ZRSR2 mutations cause mis-splicing of a compact set of genes, that Zrsr2 loss promotes aberrant and increased hematopoietic stem cell self-renewal, that simultaneous ZRSR2 and TET2 collaborate to drive malignancy, and that mis-splicing of specific downstream targets of ZRSR2 promotes clonality. We propose to build on these preliminary studies as follows: Aim 1, Determine how ZRSR2 mutations dysregulate the transcriptome and proteome in leukemia; Aim 2, Determine how disruption of ZRSR2-regulated splicing events drives clonal advantage; Aim 3, Identify the functional basis for the frequent co-occurrence of ZRSR2 and TET2 mutations in leukemia. The significance of these studies is that they will elucidate mechanistic and functional connections between ZRSR2 mutations, RNA mis-splicing, and the initiation of myeloid neoplasms. The health relatedness is that the proposed work may reveal new therapies for MDS and leukemia that specifically kill ZRSR2-mutant cells.

概括编码 RNA 剪接因子的基因是骨髓增生异常患者中最常见的一类突变综合征（MDS），并且在所有其他形式的骨髓恶性肿瘤中也很常见。相关的“剪接体突变”主要发生在四个基因中：SF3B1、SRSF2、U2AF1 和 ZRSR2。这四个基因中的三个（SF3B1、SRSF2 和 U2AF1），突变发生在杂合方式（所谓的“突变热点”）并导致功能的获得/改变相反， ZRSR2 的突变发生在整个开放阅读框内，并且似乎会导致功能丧失。 ZRSR2 的正常功能使其在白血病中常见的突变 RNA 剪接因子中独一无二： ZRSR2 是唯一一个频繁突变的因子，其主要功能是识别一类罕见的内含子被称为“小内含子”。因此，ZRSR2 突变在白血病中显着富集，并表现出独特的特征。反复剪接体突变的遗传谱和功能，但它们相对较差与 SF3B1、SRSF2 和 U2AF1 的突变进行比较研究和理解。在这里，我们建议确定 ZRSR2 的机制、功能和治疗结果我们的跨学科团队由具有白血病专业知识的医师科学家组成。生物学和患者护理 (Abdel-Wahab) 以及一位在 RNA 剪接和功能方面具有专业知识的基础科学家基因组学（Bradley）由于小内含子比大多数其他内含子更加保守，我们捕捉到了这一点。 ZRSR2 损失影响的跨物种比较对于理解如何剪接中的分子改变驱动恶性转化。在初步实验中，ZRSR2 丢失诱导的剪接将实现新的治疗方法。生成了 Zrsr2 条件敲除 (cKO) 小鼠，组装了相关患者队列，表征了我们的 Zrsr2 cKO 小鼠和 ZRSR2 突变体 MDS 的转录组，并进行了功能基因组筛选对 ZRSR2 调节的剪接事件进行建模和优先排序这些研究揭示了 ZRSR2 突变导致。一组紧凑基因的错误剪接，Zrsr2 缺失会促进造血干的异常和增加细胞自我更新，ZRSR2 和 TET2 同时协作驱动恶性肿瘤，以及 ZRSR2 的特定下游靶标促进克隆性。我们建议以这些初步研究为基础。目标 1，确定 ZRSR2 突变如何导致白血病转录组和蛋白质组失调；目标 2，确定 ZRSR2 调控的剪接事件的破坏如何驱动克隆优势；目标 3，确定 ZRSR2 和 TET2 突变在白血病中频繁同时出现的功能基础。这些研究的意义在于它们将阐明之间的机制和功能联系 ZRSR2 突变、RNA 错误剪接和骨髓肿瘤的发生与健康相关。这项拟议的工作可能会揭示专门杀死 ZRSR2 突变细胞的 MDS 和白血病的新疗法。