Genetics and Signaling of Drug Resistance and Sensitivity in AML Cell Lines, Xenografts, and Primary Patient Samples

急性髓性白血病（AML）是一种高致死性白血病亚型，5年生存率<20%。与 下一代测序的出现，一些特定的遗传病变，驱动AML，并提供 已经确定了预后信息。我们小组（co-PD/PI，Druker）以前的工作提供了证据， 伊马替尼，一种靶向ABL激酶抑制剂，可阻断慢性髓系细胞中BCR-ABL融合蛋白的活性 白血病（CML），大大提高了患者的生存率。类似的方法也适用于AML， 基因复杂的白血病，一些药物已经改善了结果，但没有一个是成功的， 由于不完全的反应和耐药性的快速发展，作为CML的ABL抑制剂。项目1 本DRSC计划，药物组合，以规避耐药性（D2CR），将侧重于了解 增强药物敏感性或耐药性的内在机制，目的是设计新的治疗方法， 战略布局对于这个项目，我们的长期目标是提名药物，提高前期药物 敏感性和/或规避耐药性，用于将在临床试验中测试的组合策略 审判我们的近期目标是确定重要的靶基因和途径， 敏感性或对特定药物的抗性，并使用细胞系，患者样品， 和异种移植物衍生的细胞。这些目标是基于我们的中心假设，即异质 AML的遗传景观与复杂的信号反馈回路一起，有助于内在的 药物敏感性和耐药性的机制。项目1将提供关键的临床前数据， 用于在项目3的主要患者样本和异种移植模型中测试的组合的候选药物。 为了实现这些目标，提出了3个目标：1）确定药物敏感/耐药的遗传机制 在AML细胞系中通过必要基因和耐药性筛选-我们将进行全基因组 CRISPR/Cas必需基因和再致敏筛选，以确定有助于 增强的药物活性或抗性。这两个屏幕组合生成的数据将提供关键 对5种选定药物（crenolanib，quizartinib， 鲁索利替尼、曲美替尼和维奈托克）。2)计算上 验证，完善和告知有助于药物内在机制的候选途径和基因 敏感性或抗性-这一迭代建模步骤将利用我们的研究所确定的内在遗传因素， 内部癌症靶向组知识库，并将优先考虑目标3中进一步验证的靶点。第三章 在假设驱动的，集中的CRISPR/Cas实验中寻找新的基因靶点-我们将开发一种 靶向CRISPR/Cas sgRNA文库，以干扰假设有助于药物敏感性的基因，或 在细胞系模型、异种移植物和原代患者样品中的耐药性。我们希望能找到基因靶点， 在项目3的药物组合测试中进一步询问。

Acute myeloid leukemia (AML), a highly lethal subtype of leukemia, has a 5-year survival rate of <20%. With the advent of next-generation sequencing, a number of specific genetic lesions that drive AML and provide prognostic information have been identified. Previous work by our group (co-PD/PI, Druker) provided proof that imatinib, a targeted ABL kinase inhibitor that blocks activity of the BCR-ABL fusion protein in chronic myeloid leukemia (CML), dramatically improves patient survival. Similar approaches have been applied to AML, a more genetically complex leukemia, and some drugs have improved outcomes, but none have been as successful as ABL inhibitors for CML due to incomplete responses and the rapid development of resistance. Project 1 of this DRSC Program, Drug Combinations to Circumvent Resistance (D2CR), will focus on understanding intrinsic mechanisms of enhanced drug sensitivity or resistance, with the goal of devising novel therapeutic strategies. For this Project, our long-term goals are to nominate drugs that enhance upfront drug sensitivity and/or circumvent resistance for use in combination strategies that will be tested in clinical trials. Our immediate goals are to identify essential target genes and pathways contributing to sensitivity or resistance to specific drugs and to validate their roles using cell lines, patient samples, and xenograft-derived cells. These goals are based on our central hypothesis that the heterogeneous genetic landscape of AML, in tandem with complex signaling feedback loops, contributes to intrinsic mechanisms of drug sensitivity and resistance. Project 1 will provide critical preclinical data to advance drug candidates for use in combinations tested in primary patient samples and xenograft models in Project 3. To accomplish these goals, 3 Aims are proposed: 1) Identify genetic mechanisms of drug sensitivity/resistance in AML cell lines through essential-gene and drug-resistance screens – We will perform genome-wide CRISPR/Cas essential gene and re-sensitization screens to identify gene targets and pathways contributing to enhanced drug activity or resistance. Data generated by the combination of these 2 screens will provide key insights into cell-intrinsic mechanisms of sensitivity or resistance to 5 select drugs (crenolanib, quizartinib, ruxolitinib, trametinib, and venetoclax) in AML cells with diverse genetic backgrounds. 2) Computationally validate, refine, and inform candidate pathways and genes contributing to intrinsic mechanisms of drug sensitivity or resistance – This iterative modeling step will leverage the intrinsic genetic factors identified by our in-house Cancer Targetome Knowledgebase and will prioritize targets for further validation in Aim 3. 3) Validate new gene targets in hypothesis-driven, focused CRISPR/Cas experiments – We will develop a targeted CRISPR/Cas sgRNA library to perturb genes hypothesized to contribute to drug sensitivity or resistance in cell line models, xenografts, and primary patient samples. We expect to identify gene targets for further interrogation in drug combination testing in Project 3.