Project 3: Therapeutic inhibition of splicing through inhibition of protein arginine methylation in leukemia

项目3：通过抑制白血病中蛋白质精氨酸甲基化来治疗性抑制剪接

• 批准号: 10474285
• 负责人: Omar Abdel-Wahab
• 金额: $ 36.77万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-24 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10474285
• 关键词: Acute Myelocytic Leukemia; Arginine; Biological Markers; Cell Death; Cell Line; Cells; Chronic Lymphocytic Leukemia; Clinical Trials; Complex; DNA Sequence Alteration; Data; Dependence; Development; Drug Screening; Dysmyelopoietic Syndromes; Enrollment; Enzymes; Epigenetic Process; Evaluation; Family; Gene Expression; Genes; Genetic; Histones; In Vitro; Leukemic Cell; Lymphoblastic Leukemia; Malignant Neoplasms; Mediating; Memorial Sloan-Kettering Cancer Center; Methylation; Molecular; Mutation; Myelogenous; Myeloid Leukemia; Non-Hodgkin' s Lymphoma; Patients; Pharmaceutical Preparations; Phase I Clinical Trials; Phase I/II Clinical Trial; Phase I/II Trial; Protein Inhibition; Protein-Arginine N-Methyltransferase; Proteins; Proteome; RNA Splicing; Refractory; Research; Safety; Sampling; Solid Neoplasm; Spliced Genes; Spliceosome Assembly Pathway; Spliceosomes; Therapeutic; Time; Toxic effect; Treatment Efficacy; Work; Xenograft procedure; acute leukemia cell; antagonist; anti-cancer; cancer cell; cancer type; cell growth; cytotoxic; drug testing; early phase clinical trial; effective therapy; efficacy evaluation; epigenome; improved; in vivo; inhibitor; leukemia; leukemia treatment; mRNA Precursor; mutant; preclinical study; predicting response; predictive marker; protein arginine methyltransferase 2; response; small hairpin RNA; small molecule; therapeutic target

ABSTRACT Leukemias often display genetic alterations that result in dysregulation of the epigenome. To identify potential epigenetic vulnerabilities, we recently performed a paired in vitro and in vivo shRNA screen in a number of acute leukemia cell lines. The results showed that myeloid as well as lymphoid leukemia cells are preferentially dependent on protein arginine methyltransferase (PRMTs), a family of enzymes that dimethylate arginine residues of many proteins. A number of prior studies have identified PRMT5 as a promising therapeutic target in cancer, which has led to an ongoing phase I clinical trial of a PRMT5 inhibitor for patients with refractory solid tumors and Non-Hodgkin's lymphoma. However, which substrates of PRMTs are most critical for anti- cancer effects of PRMT inhibition remains unknown and biomarkers predicting response to PRMT inhibition are greatly needed. Toward understanding the anticancer effects of PRMT inhibitors, we have also found that blocking PRMT function perturbs RNA splicing, and that inhibiting either symmetric (mediated by PRMT5) or asymmetric dimethyl arginine methylation (by Type I PRMTs) results in strong preferential killing of spliceosomal mutant leukemias over their wild-type (WT) counterparts. Moreover, we have observed synergistic effects of combining both type I with type II PRMT inhibition and/or inhibition of core spliceosome function. We therefore hypothesize that the main cytotoxic effect of PRMT inhibition results from modulation of splicing. We will examine our hypothesis by characterizing the effects of inhibiting type I PRMT or type II PRMTs on pre-mRNA splicing, gene expression, and the methyl-arginine proteome in WT or spliceosomal-mutant leukemia cells (Aim 1). We will also evalute whether combining inhibitors of type I PRMTs, type II PRMTs, and the splicing factor SF3b enhances toxicity to myeloid and lymphoid leukemia cells, and the relationship between these inhibitors' efficacy and mutations in various splicing factor genes (Aim 2). Finally, we will identiy biomarkers of efficacy of PRMT5 inhibition using samples from a phase I/II trial of GSK's small molecule PRMT5 antagonist (Aim 3) for the treatment of patients with refractory AML, CMML, and MDS. This project stands to greatly improve understanding of the molecular basis for the efficacy of PRMT inhibitors in cancer and to advance these drugs toward clinical trials in leukemia.

抽象的 白血病通常显示出遗传改变，导致表观基因组失调。确定潜力 表观遗传脆弱性，我们最近在许多人的体外和体内进行了配对 急性白血病细胞系。结果表明，髓样以及淋巴性白血病细胞优先 依赖蛋白精氨酸甲基转移酶（PRMTS），这是一种二甲基二氨酸氨酸的酶 许多蛋白质的残留物。许多先前的研究已将PRMT5确定为有前途的治疗靶点 在癌症中，这导致了对难治性患者的PRMT5抑制剂的I期临床试验 实体瘤和非霍奇金的淋巴瘤。但是，哪些PRMT底物对于抗 PRMT抑制的癌症影响仍然未知，生物标志物预测对PRMT抑制的反应 非常需要。 为了理解PRMT抑制剂的抗癌作用，我们还发现阻止PRMT 功能覆盖RNA剪接，并抑制对称性（由PRMT5介导）或不对称 二甲基精氨酸甲基化（按I型PRMTS）导致强烈的剪接突变体的优先杀死 对野生型（WT）对应物的白血病。此外，我们观察到了 将两种类型的I型与II型PRMT抑制和/或抑制核心剪接体功能相结合。因此，我们 假设PRMT抑制的主要细胞毒性作用是剪接的调节导致的。 我们将通过表征抑制I型PRMT或II型PRMT对的影响来检验我们的假设 WT或剪接突突中的MRNA剪接，基因表达和甲基精氨酸蛋白质组 白血病细胞（AIM 1）。我们还将评估将I型PRMT，II型PRMT和 剪接因子SF3B增强了对髓样和淋巴白血病细胞的毒性，并且关系 这些抑制剂在各种剪接因子基因中的功效和突变之间（AIM 2）。最后，我们将确定 使用GSK小分子I/II期试验中的样品的PRMT5抑制功效的生物标志物 PRMT5拮抗剂（AIM 3）用于治疗难治性AML，CMML和MD的患者。 该项目将大大提高对PRMT抑制剂功效的分子基础的理解 在癌症中并将这些药物推向白血病的临床试验。