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: 10703206
• 负责人: Ernesto Guccione
• 金额: $ 37.59万
• 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/10703206
• 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; Heterozygote; In Vitro; Individual; Leukemic Cell; Malignant Neoplasms; Mediating; Methylation; Modeling; Molecular; Mutation; Myeloid Leukemia; Patients; Pharmaceutical Preparations; Phase; Phase I Clinical Trials; Phenotype; Point Mutation; Process; Protein Inhibition; Protein Methylation; 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; pharmacologic; preclinical development; small molecule; snRNP Structural Core Protein; synthetic lethal interaction

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.

概括 剪接因子（SF）突变在多种癌症类型中高度丰富，尤其是骨髓增生异常 综合征（MDS）、急性髓性白血病（AML）和慢性淋巴细胞白血病（CLL），以及实体瘤 肿瘤，例如葡萄膜黑色素瘤。我们的小组已经确定携带 SF 突变的细胞不能耐受 对剪接催化的进一步干扰，与此一致，我们已经鉴定出剪接体突变体 癌细胞优先对破坏前 mRNA 剪接的小分子敏感。 虽然上述努力已导致正在进行的剪接体调节化合物的 I 期临床试验 对于难治性粒细胞白血病患者，我们目前不知道药物治疗的安全性或有效性 核心剪接体功能的调节。为此，我们小组最近还发现，抑制 通过抑制 Sm 蛋白精氨酸甲基化进行剪接体组装提供了另一种方法 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 (PRMT5) 介导）或不对称二甲基精氨酸甲基化 （由 I 型 PRMT（PRMT1、4 和 6）介导）降低剪接保真度，导致强烈优先杀死 SF 突变型白血病优于野生型白血病。 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“第二次打击”靶向的影响 通过抑制 I 型 (PRMT1/4/6) 和/或 II 型 (PRMT5) PRMT 进行剪接。在目标 1 中，我们将定义 单独或一起抑制 PRMT5、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，我们将了解组合的后果 相对于单独抑制 PRMT5 或 I 型 PRMT，PRMT 对 RNA 剪接和基因表达的抑制。 与上述研究并行，在目标 2 中，我们将定义 PRMT 之间合作的分子基础 抑制和 SF 突变，首先确定 PRMT5 或 I 型 PRMT 的甲基化底物，以及 其次确定个体剪接体变化是否是通过抑制 PRMT 或核心剪接体介导的 功能可以通过反义寡核苷酸来模拟，从而提供一种正交的新型治疗方法 消除 SF 突变癌细胞的方法。 这些研究的意义在于 PRMT 抑制剂现已进入患者的 I 期临床试验 与多种癌症类型相关，并确定 PRMT 抑制剂的机制效应和治疗效用 癌症的特定遗传子集可能具有令人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多种尚无治疗方法的癌症类型找到新的治疗机会 目前治疗大多数患有这些疾病的患者。