The role of the SF3B1 splicing factor in chronic lymphocytic leukemia

SF3B1剪接因子在慢性淋巴细胞白血病中的作用

基本信息

批准号：
8417317
负责人：
Catherine Ju-Ying Wu
金额：
$ 41.38万
依托单位：
DANA-FARBER CANCER INST
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-02-01 至 2018-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8417317
关键词：
ATM gene Adult Affect Alleles Automobile Driving B Cell Proliferation B-Lymphocytes Biology CD19 gene Catalytic Domain Cell Cycle Cell Line Cell Lineage Cell Survival Cell physiology Cells Cellular biology Chromosome abnormality Chronic Lymphocytic Leukemia Clinical Collaborations Complement DNA Damage DNA Repair DNA Sequence Data Development Disease Dysmyelopoietic Syndromes Employee Strikes Event Frequencies Gene Expression Profile Gene Targeting Generations Genes Genetic Hematologic Neoplasms Hematopoietic Neoplasms Heterogeneity Human Indolent Infection Inflammation Introns Investigation Kinetics Knock-in Mouse Knock-out Knowledge Large-Scale Sequencing Length Link Malignant Neoplasms Mediating Messenger RNA Methods Modeling Molecular Monitor Mouse Strains Mus Mutate Mutation Nucleic Acids Oncogenes Oncogenic Organ PTPRC gene Pathogenesis Pathway interactions Patients Pattern Physical Chemistry Process Prognostic Factor Prognostic Marker Proteins RNA RNA Sequences RNA Splicing RNA-Protein Interaction Recurrence Resistance Role Sampling Signal Transduction Silent Mutation Spliceosomes System Technology Testing Transgenic Organisms U2 Small Nuclear Ribonucleoprotein Variant aggressive therapy base cell behavior chromosome 13q loss deep sequencing del(11q)exome sequencing genetic manipulation improved in vivo inhibitor/antagonist insight leukemia leukemogenesis mRNA Precursor mouse model mutant new therapeutic target notch protein novel outcome forecast protein complex protein protein interaction public health relevance repository response tool transcriptome sequencing

项目摘要

DESCRIPTION (provided by applicant): Through large-scale DNA sequencing, we recently identified the core spliceosome factor, SF3B1, as a novel cancer gene in chronic lymphocytic leukemia (CLL). SF3B1 functions in the catalytic core of the U2 small nuclear ribonucleoprotein (U2 snRNP), an essential RNA-protein complex involved in pre-mRNA splicing. Several features of this new cancer gene make it a high priority for investigation. First, SF3B1 is mutated at a high frequency in CLL, with all mutations localizing to a discrete gene region, and with half recurrent at K700E. Second, mutation in SF3B1 is significantly associated with del(11q), a cytogenetic abnormality associated with aggressive disease, and yet, is an independent predictive marker of poor prognosis. Third, CLL samples with SF3B1 mutation demonstrate altered pre-mRNA splicing in known spliceosome target genes compared to samples with wildtype SF3B1. Finally, SF3B1-K700E was recently identified as a recurring mutation in myelodysplasia. Mutations in SF3B1 and modulation of RNA splicing are likely to represent a novel oncogenic process across hematologic malignancies and preferentially in aggressive forms of CLL. Our hypothesis is that mutated SF3B1 generates mis-spliced pre-mRNAs, encoding proteins that promote leukemogenesis. Our strategy for functionally linking SF3B1 mutation and CLL pathogenesis is to first define the effects of SF3B1 mutation on survival and proliferation of B cells, and on other pathways that we recently identified as critical to CLL (inflammation, Notch1 and Wnt signaling, DNA damage/repair) (Aim 1). Second, we will identify the mechanism by which these changes in cellular function are mediated (Aim 2). Since SF3B1 is essential for RNA splicing, we will examine the effects of SF3B1 mutation on critical protein-protein and protein-RNA interactions within the spliceosome, and use RNA sequencing to globally identify the novel splice variants generated by SF3B1 mutation. Understanding of the critical cellular processes affected by SF3B1 mutation (per Aim 1) will prioritize the candidate splice variants to be functionally validated as crucial to promoting CLL. Because SF3B1 mutation appears to function in a cell lineage specific context, we will carry out all studies in B cell lines or primary normal B cells; into which mutated or wildtype SF3B1 is introduced using novel biomolecule delivery or infection methods that our group has pioneered. Additionally, we will validate our findings using CLL samples naturally harboring SF3B1 mutations. Third, to definitively establish the role of SF3B1 mutation in driving CLL, we are generating a transgenic conditional knock-in SF3B1-K700E mouse (Aim 3). We will examine these mice for in vivo evidence of lymphohematopoietic accumulation of clonal B cells when SF3B1-K700E expression is restricted to CD19+ B cells alone or in combination with other CLL-generating genetic alterations. The proposed studies are anticipated to provide critical insights into a novel splicing mechanism underlying CLL (with implications for other blood cancers) that are expected to contribute to improved strategies to treat this incurable disease, especially given the development of spliceosome inhibitors.

描述（申请人提供）：通过大规模DNA测序，我们最近鉴定出核心剪接体因子SF3B1是慢性淋巴细胞白血病（CLL）中的一种新型癌症基因。 SF3B1 在 U2 小核核糖核蛋白 (U2 snRNP) 的催化核心中发挥作用，U2 snRNP 是一种参与前 mRNA 剪接的重要 RNA-蛋白质复合物。这种新癌症基因的几个特征使其成为研究的重中之重。首先，SF3B1 在 CLL 中发生高频率突变，所有突变都定位于离散基因区域，并且一半在 K700E 处复发。其次，SF3B1 突变与 del(11q) 显着相关，del(11q) 是一种与侵袭性疾病相关的细胞遗传学异常，但它是不良预后的独立预测标志物。第三，与具有野生型 SF3B1 的样本相比，具有 SF3B1 突变的 CLL 样本显示已知剪接体靶基因中的前 mRNA 剪接发生了改变。最后，SF3B1-K700E 最近被鉴定为骨髓增生异常的复发突变。 SF3B1 的突变和 RNA 剪接的调节可能代表血液系统恶性肿瘤中的一种新的致癌过程，尤其是侵袭性 CLL 中。我们的假设是突变的 SF3B1 产生错误剪接的前 mRNA，编码促进白血病发生的蛋白质。我们将 SF3B1 突变与 CLL 发病机制在功能上联系起来的策略是首先确定 SF3B1 突变对 B 细胞存活和增殖的影响，以及对我们最近确定的对 CLL 至关重要的其他途径（炎症、Notch1 和 Wnt 信号传导、DNA 损伤/修复）（目标 1）。其次，我们将确定介导这些细胞功能变化的机制（目标 2）。由于 SF3B1 对于 RNA 剪接至关重要，因此我们将检查 SF3B1 突变对剪接体内关键蛋白质-蛋白质和蛋白质-RNA 相互作用的影响，并使用 RNA 测序来全面鉴定由 SF3B1 突变产生的新剪接变体。了解受 SF3B1 突变影响的关键细胞过程（根据目标 1）将优先考虑对候选剪接变体进行功能验证，认为其对于促进 CLL 至关重要。由于 SF3B1 突变似乎在细胞谱系特定背景下发挥作用，因此我们将在 B 中进行所有研究细胞系或原代正常B细胞；使用我们小组首创的新型生物分子传递或感染方法将突变或野生型 SF3B1 引入其中。此外，我们将使用天然含有 SF3B1 突变的 CLL 样本来验证我们的发现。第三，为了明确确定 SF3B1 突变在驱动 CLL 中的作用，我们正在生成转基因条件敲入 SF3B1-K700E 小鼠（目标 3）。当 SF3B1-K700E 表达仅限于单独的 CD19+ B 细胞或与其他产生 CLL 的遗传改变组合时，我们将检查这些小鼠体内克隆 B 细胞淋巴造血积累的证据。拟议的研究预计将为小说提供重要的见解 CLL 的剪接机制（对其他血癌也有影响）有望有助于改进治疗这种不治之症的策略，特别是考虑到剪接体抑制剂的发展。