Targeting an RNA Binding Protein Network in Acute Myeloid Leukemia

靶向急性髓系白血病中的 RNA 结合蛋白网络

• 批准号: 10408047
• 负责人: Omar Abdel-Wahab
• 金额: $ 54.47万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10408047
• 关键词: Ablation; Acute Myelocytic Leukemia; Adaptor Signaling Protein; Address; Adult; Binding; Biological; CD34 gene; CRISPR/Cas technology; Cancer cell line; Cell Line; Cell physiology; Cells; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; Data; Dependence; Disease; Drug Targeting; Evaluation; Excision; Exons; Genetic; Genetic Engineering; Genetic Models; Genetic Transcription; Growth; HOXA9 gene; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Histologic; Human; Impairment; In Vitro; Introns; Link; Liquid substance; Maintenance; Malignant - descriptor; Malignant Neoplasms; Mediating; Messenger RNA; Methods; Modeling; Mutation; Non-Malignant; Nucleosomes; Oncogenic; Patients; Pharmaceutical Preparations; Pharmacology; Physiological; Play; Population; Protein Splicing; Proteins; Proteomics; RNA; RNA Binding; RNA Recognition Motif; RNA Splicing; RNA analysis; RNA-Binding Proteins; Recurrence; Role; Sampling; Solid; Sulfonamides; Time; Tissues; Transcription Elongation; Translations; Up-Regulation; acute myeloid leukemia cell; anti-cancer; base; cancer cell; cancer survival; cell type; conditional knockout; improved; in vivo; insight; leukemia; leukemia initiating cell; loss of function; member; mouse model; mutant; novel; novel strategies; overexpression; patient derived xenograft model; progenitor; stem; treatment strategy; tumorigenesis; ubiquitin ligase

RNA-binding proteins (RBPs) are essential modulators of transcription and translation frequently dysregulated in cancer. We recently systematically interrogated RBP dependencies in a number of human cancers using a comprehensive CRISPR/Cas9 domain-focused screen targeting RNA-binding domains (RBDs) of 490 classical RBPs. This uncovered a network of physically interacting RBPs upregulated in acute myeloid leukemia (AML) and crucial for maintaining physiological RNA splicing and AML survival. Genetic targeting of one key member of this network, RBM39, repressed cassette exon inclusion and promoted intron retention within mRNAs encoding HOXA9 targets as well as in other RBPs preferentially required in AML. Fortuitously, it has recently been described that a class of clinically validated anti-cancer sulfonamide compounds (including the drugs indisulam and E7820) mediate RBM39 degradation as their dominant cellular mechanism of action. This occurs via novel interactions between these compounds and the DCAF15 adapter protein of the CUL4/Ddb1 ubiquitin ligase complex with RBM39 as a neo-substrate. Treatment of AML cells with such compounds in vitro and in vivo resulted in similar lethal cellular effects due to perturbations in RNA splicing. The effects of RBM39 loss on splicing resulted in preferential lethality of spliceosomal mutant AML, providing a novel strategy for treatment of AML bearing recurrent mutations in RBPs that regulated splicing. Overall these data identify RBM39 as central to a network of functionally and physically interacting RBPs upregulated in AML over normal hematopoietic precursors and required for AML maintenance. Despite these insights we do not yet understand the basis for the cell- and context-specific roles of RBM39 in malignant versus normal hematopoietic cells. We also do not understand the exact mechanisms by which RBM39 loss results in eradication of AML. We hypothesize that RBM39 is differentially required in malignant versus normal hematopoietic cells, may be differentially required depending on the precise stage of hematopoiesis, and will be required for leukemia initiation as well as maintenance. These hypotheses will be addressed in two Specific Aims. Aim 1 will determine the biological role of RBM39 in normal and malignant hematopoiesis. In this Aim, we will utilize a novel genetic model for genetic deletion of RBM39 in vivo in a cell- and time-specific manner to rigorously dissect the roles of RBM39 in malignant versus normal hematopoietic stem and progenitor cell populations. Aim 2 will identify the mechanistic basis for cell-type and disease-specific roles for RBM39 in normal and malignant hematopoietic cells. In this Aim we will compare the direct RNA binding targets and effects of RBM39 loss on splicing across normal and malignant hematopoietic cells. In addition, we will evaluate a potential novel for RBM39 in transcriptional elongation by the FACT complex, identified by our preliminary studies as an interactor of RBM39.

RNA结合蛋白（RBP）是转录的必要调节剂，翻译经常失调 在癌症中。最近，我们系统地系统地询问了许多人类癌症中的RBP依赖性 综合CRISPR/CAS9以域屏幕为目标RNA结合域（RBD）490经典 RBP。这发现了在急性髓样白血病（AML）中上调的物理相互作用的RBP网络 对于维持生理RNA剪接和AML存活至关重要。一个关键成员的遗传靶向 在该网络中，RBM39抑制了盒式外显子包含并促进了mRNA内的内含子保留率 编码HOXA9目标以及其他RBP中的AML中所需的其他RBP。幸运的是，它最近有 被描述为一类经过临床验证的抗癌磺酰胺化合物（包括药物 Indisulam和E7820）将RBM39降解作为其主要的细胞作用机理。这 通过这些化合物与CUL4/DDB1的DCAF15适配器蛋白之间的新型相互作用发生 泛素连接酶复合物与RBM39作为新材料。用此类化合物在 体内和体内由于RNA剪接的扰动而导致相似的致命细胞作用。效果 RBM39剪接损失导致剪接突变体AML的优先致死性，提供了一种新型策略 用于处理调节剪接的RBP中的AML复发突变。 总体而言，这些数据将RBM39识别为功能和物理交互网络的核心 在正常的造血前体中，在AML中上调，维持AML所需。尽管如此 洞察力我们尚未理解RBM39在恶性中的细胞和上下文特定角色的基础 与正常的造血细胞相比。我们也不了解RBM39损失的确切机制 导致根除AML。我们假设RBM39在恶性和 正常的造血细胞可能需要差异化，具体取决于 造血，将需要白血病启动和维护。这些假设 将以两个具体目标解决。 AIM 1将确定RBM39在正常和 恶性造血。在此目标中，我们将利用一种新型的遗传模型来用于RBM39的遗传缺失 体内以细胞和特定时间的方式进行严格剖析RBM39在恶性与正常作用中的作用 造血茎和祖细胞群体。 AIM 2将确定细胞类型的机械基础和 RBM39在正常和恶性造血细胞中的疾病特异性作用。在此目标中，我们将比较 直接RNA结合靶标和RBM39损失对正常和恶性造血的剪接的影响 细胞。此外，我们将通过事实评估转录延伸的RBM39的潜在小说 复杂，我们的初步研究将其确定为RBM39的相互作用。