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的患者中最常见的突变类别综合征（MDS），在所有其他形式的髓样恶性肿瘤中也很常见。这些白血病 - 相关的“剪接突变”主要发生在四个基因中：SF3B1，SRSF2，U2AF1和ZRSR2。在这四个基因中的三个（SF3B1，SRSF2和U2AF1），突变发生在特定的氨基酸残基中杂合的方式（所谓的“突变热点”），并导致功能的增益/改变。相比之下， ZRSR2中的突变发生在整个开放式阅读框架中，并且似乎会损失功能。而且， ZRSR2的正常功能使其在白血病中通常突变的RNA剪接因子中独一无二： ZRSR2是唯一识别罕见类内含子类的主要功能的唯一频繁的突变因素被称为“次要内含子”。这就是ZRSR2突变在白血病中显着富集，并且表现出独特的复发剪接突变中的遗传光谱和功能，但它们相对较差与SF3B1，SRSF2和U2AF1中的突变相比，已进行了研究和理解。在这里，我们建议确定ZRSR2的机械，功能和热后果白血病突变。我们的跨学科团队由一个具有白血病专业知识的身体科学家组成生物学和患者护理（Abdel-Wahab）和具有RNA剪接和功能专家的基础科学家基因组学（布拉德利）。由于次要内含子比大多数其他内含子更保守，因此我们假设 ZRSR2损失影响的跨物种比较将特别有用剪接驱动恶性转化的分子改变。此外，我们假设这种异常 ZRSR2损失引起的剪接将实现新颖的治疗方法。在初步实验中，我们产生了一个有条件敲除（CKO）小鼠的ZRSR2，组装了相关患者队列，表征了我们的ZRSR2 CKO小鼠和ZRSR2突变的MDS的转录组，并进行了功能性基因组筛选建模并确定ZRSR2调节的剪接事件。这些研究表明ZRSR2突变引起一组紧凑的基因的分解，ZRSR2损失会促进异常和造血茎增加细胞自我更新，简单的ZRSR2和TET2协作以驱动恶性肿 ZRSR2的特定下游靶标可促进克隆性。我们建议以这些初步研究为基础以下内容：目标1，确定ZRSR2突变如何使白血病中的转录组和蛋白质组失调； AIM 2，确定ZRSR2调节的剪接事件的破坏如何驱动克隆优势；目标3，识别白血病中ZRSR2和TET2突变经常共同出现的功能基础。这些研究的重要性是它们将阐明 ZRSR2突变，RNA失误和髓样肿瘤的主动性。健康相关性是拟议的工作可能揭示了针对特异性杀死ZRSR2突变细胞的MDS和白血病的新疗法。