(PQ8) Genetically faithful murine models for studying disease progression in chronic lymphocytic leukemia

项目摘要 现代医学的一个关键目标是利用我们对个体独特基因构成的知识 让患者做出个性化的治疗决定。慢性淋巴细胞白血病(CLL)的研究进展 我们对其疾病遗传学的了解以及在临床实践中采用新的治疗药物 近几年来一直很快。因此，现在比以往任何时候都更迫切地需要将患者与 适当的治疗选择。鉴于CLL和我们的 了解其遗传异质性，我们的愿景是，通往精确医学的道路可以 用CLL开拓进取。这一愿景的关键是发展忠诚的动物模型，因为这些模型将 毫无疑问，加快针对基因定义的亚群的药物的临床前测试。在此，我们 建议利用整个CLL基因组数据，包括从基因到甲基化的研究，以合理地 创建提供全范围遗传变异性的小鼠模型，以总结临床 患者的变异性。这一目标是可实现的，因为我们最近证明了 从患者样本的无偏测序中鉴定的2个假定的CLL驱动事件的表达产生 与人类疾病高度一致的类CLL疾病。具体地说，突变的SF3B1与 ATM缺失(在患者样本中显著相关)导致克隆性疾病的发生 18岁老年人外周血、骨髓和脾中CD19+CD5+B细胞的低外显率 几个月)小鼠，可以通过体内传代繁殖。以这项工作为基础，我们现在提出 为了调查CLL中采取不同进化路径的假设，取决于 疾病起始点和遗传事件的特定组合起作用 恶性，而另一些则是疾病加速甚至致癌转化的关键。至 为了实现这一目标，我们建议利用最近可用的便捷的基因组编辑方法，以及强大的 我们优化了工作流程，通过植入基因组编辑的B细胞来遗传操作成熟的B细胞 祖细胞，以便灵活地筛选各种候选驱动程序突变对功能的影响 A B细胞在体内的情况。我们的目标是从正常的B细胞中确定启动疾病所需的阶段性事件 到惰性恶性状态(目标1)，从惰性恶性到更进展性疾病(目标2)，以及 甚至到侵袭性淋巴瘤转化(目标3)。建立这样的动物模型有望提供 这是一个宝贵的资源，将使您能够深入了解驱动程序更改的功能影响，以 加速疾病预测，促进对新的组合疗法的合理评估，以及 解剖CLL细胞与其体内微环境的相互作用。因此，我们寻求创造同样的 小鼠的遗传异质性，就像CLL患者一样，这样我们就可以忠实地建立疾病模型，并提供 提前测试疗法的手段--这是实现精准医学的垫脚石。

Project Summary A key goal of modern-day medicine is to use our knowledge of the unique genetic makeup of an individual patient to make personalized therapeutic decisions. For chronic lymphocytic leukemia (CLL), the advances in our knowledge of its disease genetics as well as the adoption of novel therapeutic agents in clinical practice have been rapid over recent years. Thus, the need now is ever more urgent to match patients with the appropriate therapeutic choice. Given the wealth of available human genetic data in CLL and our understanding of its genetic heterogeneity, our vision is that the path to precision medicine can be trail-blazed with CLL. Critical to this vision is the development of faithful animal models, since these would undoubtedly accelerate the preclinical testing of agents against genetically-defined subgroups. Herein, we propose leveraging the entirety of CLL genomics data, including genetic to methylation studies, to rationally create mouse models that provide the full range of genetic variability in order to recapitulate the clinical variability of patients. This goal is implementable because we recently demonstrated that the combined expression of 2 putative CLL driver events, identified from unbiased sequencing of patient samples, generates CLL-like disease that is highly faithful to the human disease. Specifically, co-expression of mutated Sf3b1 with Atm deletion (significantly associated together in patient samples) 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. With this work as a foundation, we now propose to investigate the hypothesis that distinct evolutionary paths are undertaken in CLL depending on the starting points of disease and that specific combinations of genetic events function to initiate malignancy, while others are critical for disease acceleration and even oncogenic transformation. To achieve this goal, we propose to leverage recently available facile genome-editing approaches, and a robust workflow we optimized to genetically manipulate mature B cells through engraftment of genome-edited B cell progenitor cells, in order to nimbly screen the functional impact of a variety of candidate driver mutations within a B cell context in vivo. We aim to identify the stepwise events required to initiate disease from normal B cells to a state of indolent malignancy (Aim 1), from indolent malignancy to more progressive disease (Aim 2), and even to aggressive lymphoma transformation (Aim 3). Generating such animal models is expected to provide an invaluable resource which will enable deep understanding of the functional impact of driver alterations, to accelerate disease prognostication, to facilitate rational evaluation of novel and combinatorial therapeutics, and to dissect the interaction of CLL cells with their in vivo microenvironment. Thus, we seek to create the same genetic heterogeneity in mice as in CLL patients so that we can faithfully model disease and provide a means to test therapeutics in advance—a stepping stone towards achieving precision medicine.