Therapeutic targeting of RNA splicing catalysis through inhibition of Protein Arginine Methylation

通过抑制蛋白质精氨酸甲基化来治疗 RNA 剪接催化

• 批准号: 10393007
• 负责人: Ernesto Guccione
• 金额: $ 38.36万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10393007
• 关键词: Acute Myelocytic Leukemia; Alleles; Antisense Oligonucleotides; Arginine; Catalysis; Cells; Chronic Lymphocytic Leukemia; Data; Disease; Drug Targeting; Dysmyelopoietic Syndromes; Evaluation; Event; Gene Expression; Genes; Genetic; Health; In Vitro; Individual; Leukemic Cell; Malignant Neoplasms; Mediating; Methylation; Modeling; Molecular; Mutation; Myeloid Leukemia; Patients; Pharmaceutical Preparations; Pharmacology; Phase; Phase I Clinical Trials; Phenotype; Point Mutation; Process; Protein Inhibition; Protein Splicing; Protein-Arginine N-Methyltransferase; Proteins; Proteome; RNA Splicing; RNA methylation; RNA-Binding Proteins; RNA-targeting therapy; Refractory; Safety; Small Nuclear Ribonucleoproteins; Solid Neoplasm; Spliceosome Assembly Pathway; Spliceosomes; Therapeutic; Therapeutic Effect; Uveal Melanoma; Work; cancer cell; cancer type; cell killing; clinical development; curative treatments; early phase clinical trial; efficacy evaluation; in vivo; inhibitor; leukemia; mRNA Precursor; mutant; myeloid leukemia cell; novel therapeutic intervention; novel therapeutics; preclinical development; small molecule; snRNP Structural Core Protein

SUMMARY Mutations in splicing factors (SF) are highly enriched in a variety of cancer types, particularly myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and chronic lymphocytic leukemia (CLL), in addition to solid tumors such as uveal melanoma. Our group has identified that cells bearing SF mutations cannot tolerate further perturbations to splicing catalysis and, consistent with this, we have identified that spliceosomal mutant cancer cells are preferentially sensitive to small molecules that disrupt pre-mRNA splicing. While the above effort has resulted in an ongoing phase I clinical trial of a spliceosome modulatory compound for patients with refractory myeloid leukemias, we do not currently know the safety or efficacy of pharmacologic modulation of core spliceosome function. To this end, our group has also recently identified that inhibiting spliceosomal assembly through inhibition of arginine methylation of Sm proteins provides an alternate means of therapeutic splicing inhibition. We have identified that inhibiting either symmetric arginine methylation (mediated by the protein arginine methyltransferase 5 (PRMT5)) or asymmetric dimethyl arginine methylation (mediated by type I PRMTs (PRMT1, 4, and 6)) reduces splicing fidelity resulting in strong preferential killing of SF-mutant leukemias over their wildtype counterparts. Here we aim to determine if in leukemia, SF-mutations portend greater vulnerability to a “second hit” targeting splicing through inhibition of type I (PRMT1/4/6) and/or type II (PRMT5) PRMTs. In Aim 1 we will define the therapeutic potential of inhibiting PRMT5, type I PRMTs, and core spliceosome function, alone or together in leukemia models with or without a SF mutation. In addition, we will understand the consequences of combined PRMT inhibition on RNA splicing and gene expression relative to inhibiting PRMT5 or Type I PRMTs alone. In parallel to the above studies, in Aim 2, we will define the molecular basis for the cooperation between PRMT inhibition and SF mutations, by first determining the methylation substrates of PRMT5 or Type I PRMTs, and secondly by determining if individual spliceosomal changes mediated by inhibiting PRMTs or core spliceosome function can be mimicked by anti-sense oligonucleotides, thereby providing an orthogonal novel therapeutic approach to eliminate SF-mutant cancer cells. The significance of these studies is that inhibitors of PRMTs are now entering phase I clinical trials in patients with a variety of cancer types and defining the mechanistic effects and therapeutic utility of PRMT inhibitors for specific genetic subsets of cancers may have incredible therapeutic importance. The health relatedness is that our studies may identify new therapeutic opportunities for a variety of cancer types that have no curative therapies for the majority of patients with these diseases currently.

总结 剪接因子（SF）突变在多种癌症类型中高度富集，特别是骨髓增生异常 在一些实施方案中，除了实体瘤治疗外，还治疗骨髓增生异常综合征（MDS）、急性髓性白血病（AML）和慢性淋巴细胞白血病（CLL）。 肿瘤如葡萄膜黑色素瘤。我们的研究小组已经确定，携带SF突变的细胞不能耐受 进一步干扰剪接催化，与此一致，我们已经确定剪接体突变体， 癌细胞优先对破坏前mRNA剪接的小分子敏感。 虽然上述努力已经导致剪接体调节化合物的正在进行的I期临床试验， 对于难治性髓系白血病患者，我们目前尚不清楚药物治疗的安全性或有效性。 核心剪接体功能的调节。为此，我们的小组最近还确定， 通过抑制Sm蛋白的精氨酸甲基化进行剪接体组装提供了一种替代方法 治疗性剪接抑制我们已经发现，抑制对称精氨酸甲基化 （由蛋白质精氨酸甲基转移酶5（PRMT 5）介导）或不对称二甲基精氨酸甲基化 （由I型PRMT（PRMT 1、4和6）介导）降低剪接保真度，导致对 SF突变型白血病的发病率高于野生型。 在这里，我们的目标是确定在白血病中，SF-突变是否预示着更容易受到“二次打击”的影响。 通过抑制I型（PRMT 1/4/6）和/或II型（PRMT 5）PRMT进行剪接。在目标1中，我们将定义 单独或一起抑制PRMT 5、I型PRMT和核心剪接体功能的治疗潜力， 具有或不具有SF突变的白血病模型。此外，我们将了解合并的后果 相对于单独抑制PRMT 5或I型PRMT，PRMT对RNA剪接和基因表达的抑制。 在上述研究的同时，在目标2中，我们将定义PRMT之间合作的分子基础。 通过首先确定PRMT 5或I型PRMT的甲基化底物， 其次，通过确定是否通过抑制PRMT或核心剪接体介导个体剪接体的变化， 功能可以通过反义寡核苷酸模拟，从而提供正交的新治疗剂， 消除SF突变癌细胞的方法。 这些研究的意义在于PRMT抑制剂现在进入了患者的I期临床试验 与各种癌症类型，并定义PRMT抑制剂的机制作用和治疗效用， 癌症的特定遗传亚群可能具有难以置信的治疗重要性。健康相关性是 我们的研究可能会为各种无法治愈的癌症类型找到新的治疗机会， 目前大多数患有这些疾病的患者的治疗方法。