Cooperation of SF3B1 mutations and ATM deletions in the pathogenesis of chronic lymphocytic leukemia

项目摘要 世界范围内的测序工作已经发现了与疾病相关的反复出现的新的基因损伤 进展，共同共生的推断模式，并表征了克隆进化对 慢性淋巴细胞白血病的治疗。尽管有丰富的可用遗传信息，这些分析 所有这些都依赖于统计推断，因此限制了将基因型与表型联系起来的可能性。目前， 理解高频遗传损伤的功能以及它们如何与它们的共生现象协同作用 导致CLL启动和进展的突变是不可用的。在这项提案中，我们的目标是了解 慢性淋巴细胞性白血病中两种最常见的遗传性损害(SF3B1突变和ATM缺失)的机械性影响 CLL的启动和进展，首要目标是了解CLL生物学，产生新的小鼠 模型，并找到治疗这些病变的CLL的新策略。 这一建议是基于我们的发现，突变的SF3B1和ATM缺失的共同表达导致了 小鼠外周血、骨髓和脾中克隆性致病CD19、CD5 B细胞的发育 老龄(18个月)小鼠，可通过体内传代进行繁殖。有趣的是，全基因组测序 来自小鼠CLL的DNA显示出反复的染色体扩增，表明染色体不稳定 SF3B1突变和ATM缺失小鼠慢性淋巴细胞白血病的发病机制。我们现在建议 研究SF3B1突变通过剪接相关的R-RNA促进基因组不稳定性的假说 ATM缺失时的环形成通过减少与R-环相关的R-环进一步增加基因组的不稳定性 DNA损伤修复(目标1)。我们进一步假设，R环形成的调制有助于 CLL的加速(目标2)。因此，针对RNA剪接和DNA损伤反应检查点 可能为这些病变的CLL提供合成细胞毒性(目标3)。拟议工作完成后， 为解释剪接因子突变如何影响基因组不稳定性和 有助于肿瘤的发生，并为设计新的临床试验提供理论基础 突变和自动取款机的缺失。

Project Summary World-wide sequencing efforts have identified recurrent novel genetic lesions associated with disease progression, inferred patterns of common co-occurrence, and characterized clonal evolution in response to treatments in chronic lymphocytic leukemia. Despite the wealth of available genetic information, these analyses all rely on statistical inference, thus limiting the possibility to link the genotype to the phenotype. Currently, understanding functions of high frequency genetic lesions and how they cooperate with their co-occurring mutations to cause CLL initiation and progression are not available. In this proposal, we aim to understand how two of the most recurrent genetic lesions in CLL (SF3B1 mutations and ATM deletions) mechanistically impact CLL initiation and progression with the overarching goal to understand CLL biology, generate novel murine model, and find new strategies for treating CLL with these lesions. This proposal is based on our finding that co-expression of mutated Sf3b1 with Atm deletion resulted in the development of clonal pathognomonic CD19+CD5+ B cells in blood, marrow and spleen at low penetrance in aged (18 months) mice, that can be propagated by in vivo passaging. Interestingly, whole-genome sequencing of DNA from murine CLL revealed recurrent chromosome amplifications, suggesting chromosome instability as a mechanism contributing to CLL in the mice with Sf3b1 mutation and Atm deletion. We now propose to investigate the hypothesis that SF3B1 mutations promote genomic instability through RNA splicing related R- loop formation while ATM deletion further augment genomic instability through decreasing R-loop associated DNA damage repair (Aim 1). We further hypothesize that modulation of the R-loop formation is contributing to the acceleration of CLL (Aim 2). Thus, targeting both RNA splicing and DNA damage response checkpoints are likely to provide synthetic cytotoxicity for CLLs with these lesions (Aim 3). Completion of the proposed work will create a fundamental foundation to explain how splicing factor mutations impact genomic instability and contribute to oncogenesis, and provide rationale for designing novel clinical trials in CLL patients with both SF3B1 mutations and ATM deletions.