Targeting defective spliceosomal pathway in myeloid malignancies

靶向骨髓恶性肿瘤中的缺陷剪接体途径

• 批准号: 10434248
• 负责人: VALERIA VISCONTE
• 金额: $ 23.17万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10434248
• 关键词: 3' Splice Site; AML/MDS; Acute Myelocytic Leukemia; Adult; Animal Model; Autophagocytosis; Binding; Biochemical; Biological Assay; Cancer Model; Cell Line; Cell model; Cells; Chemicals; Clinical Data; Clinical Research; Clonal Evolution; Code; Computer-Aided Design; Crystallization; Data; Development; Disease model; Drug Targeting; Dysmyelopoietic Syndromes; Erythropoiesis; Essential Genes; Exhibits; Future; Gene Deletion; Genes; Glioma; Goals; Growth; Hematopoietic; Human; IRAK4 gene; Impairment; In Vitro; Intervention; K-562; K562 Cells; Lead; Libraries; Malignant Neoplasms; Malignant neoplasm of lung; Malignant neoplasm of pancreas; Malignant neoplasm of urinary bladder; Messenger RNA; Missense Mutation; Modeling; Mus; Mutate; Mutation; Myeloid Cells; Myeloproliferative disease; NF-kappa B; Oncogenic; Outcome; Pathway interactions; Patients; Pattern; Pharmacology; Phase I Clinical Trials; Prognosis; Protein Isoforms; Proteins; Quantitative Reverse Transcriptase PCR; RNA Splicing; Regulation; Risk; SF1; SRSF2 gene; Sampling; Signal Transduction; Solid Neoplasm; Spliceosome Assembly Pathway; Spliceosomes; Structure; Structure-Activity Relationship; Therapeutic; Therapeutic Effect; Therapeutic Studies; Toxic effect; Transgenic Mice; Validation; Xenograft procedure; acute myeloid leukemia cell; base; cancer cell; cancer survival; chemical synthesis; disease phenotype; efficacy evaluation; exome; improved; in vivo; inhibitor; innovation; leukemia; mRNA Precursor; malignant breast neoplasm; melanoma; mouse model; mutant; novel; novel therapeutics; preclinical development; preference; prognostic; prognostic value; recruit; screening; small molecule therapeutics; targeted agent; targeted sequencing; therapeutic candidate; therapeutic development; therapeutic target; tool; transcriptome; transcriptomics

Abstract Whole-exome and targeted sequencing of MDS patients’ samples have led to discover a set of genes (SF3B1, U2AF1, SRSF2, ZRSR2 and LUC7L2) encoding mutant RNA splicing factors that alter expression patterns of protein isoforms in clonal evolution of hematopoietic cells during MDS progression. Subsequent studies found occurrences of these splicing factor mutations in AML and solid tumors. Clinical data also showed heterozygous missense mutations or hemizygous deletions of these genes are mostly mutually exclusive implying that mutations in multiple proteins in splicing regulation may be lethal in MDS cells. To date, only one compound, H3B-8800, to target SF3B1 is in phase I clinical trial to treat MDS and other myeloid malignancies. No agents targeting other mutated splicing factors are in pre-clinical development and if other mutant factors can be potential drug targets is unknown. Among them, U2AF1 mutations occurred in early MDS clones and are poor prognostic features for progression to leukemia. Studies showed U2AF1S34F hematopoietic cells and transgenic mouse models are sensitive to sudemycin that targets SF3B1. Recently, U2AF1wt was suggested to be a haplo-essential gene for the survival of cancer cells containing U2AF1 mutation. Our central hypothesis is that U2AF1wt inhibition may induce synthetic lethality to U2AF1S34F clones that depends on U2AF1wt for survival. Our rationale is that blockade of U2AF1/U2AF2 association may impair U2AF1wt function. Using fragment-based library screening, we have identified a hit compound that inhibited the U2AF1/U2AF2 binding and exhibited selective growth inhibition in K562-U2AF1S34F and human primary cells carrying U2AF1 mutations but not their wild-type counterparts. Our objective of this proposal is to develop a new class of U2AF1 inhibitors based on the hit and assess the therapeutic concept of synthetic lethality in MDS/AML disease models. Our long-term goal is to develop small-molecule therapeutics to target cancer cells defective in the spliceosome pathway. To achieve our goal, we have devised two specific aims: 1) Optimization of U2AF1 inhibitors by integrating computer-aided design with chemical syntheses; 2) Study the therapeutic effects of U2AF1 inhibitors using in vitro and in vivo U2AF1mut MDS/AML models. In Aim 1, we will improve the activity and selectivity of U2AF1 inhibitors based on the preliminary structure activity relationship and selectivity data of SF1-8 by integrating chemical syntheses, computer-aided design, biochemical assays and the co- crystal structure determination. In Aim 2, we will assess the activities of our U2AF1 inhibitors in MDS/AML cellular models, analyze transcriptome and splicing pattern changes in cell lines treated with U2AF1 inhibitors and determine the effects of our inhibitors on erythropoiesis in xenograft mouse models. Our application is innovative and significant, because it builds on our discovery of the hit to U2AF1, an emerging novel target associated with the transformation of myeloid malignancies, and has the potential to establish a new therapeutic platform to treat MDS/AML by pharmacologically targeting mutant U2AF1 cells.

抽象的 MDS患者样品的全外观和靶向测序已导致发现一组基因（SF3B1， U2AF1，SRSF2，ZRSR2和LUC7L2）编码突变的RNA剪接因子，以改变的表达模式 MDS进展过程中造血细胞克隆进化中的蛋白质同工型。随后的研究发现 这些剪接因子突变的发生在AML和实体瘤中。还显示了临床数据 这些基因的杂合错义突变或半合子缺失主要是相互排斥的 暗示在剪接调节中多种蛋白质中的突变可能在MDS细胞中致命。迄今为止，只有一个 针对靶标SF3B1的化合物H3B-8800正在进行I期临床试验中，以治疗MDS和其他骨髓恶质。 没有针对其他突变剪接因子的代理是临床前发育和其他突变因素 可能是潜在的药物靶标是未知的。其中，U2AF1突变发生在早期的MDS克隆中， 是前进到白血病的不良预后特征。研究表明U2AF1S34F造血细胞和 转基因小鼠模型对针对SF3B1的sudemycin敏感。最近，建议使用U2AF1WT 成为一种单倍肯定基因，用于含有U2AF1突变的癌细胞存活。我们的中心假设是 U2AF1WT抑制可能会引起依赖于U2AF1WT的U2AF1S34F克隆的合成杀伤力 生存。我们的理由是，U2AF1/U2AF2关联的封锁可能会损害U2AF1WT功能。使用 基于片段的库筛选，我们已经确定了一种抑制U2AF1/U2AF2结合的命中化合物 并在K562-U2AF1S34F和携带U2AF1的人类原代细胞中暴露了选择性的生长抑制 突变，但不是它们的野生型。该提案的目的是开发一个新的类 U2AF1抑制剂基于HIT并评估MDS/AML中合成致死性的治疗概念 疾病模型。我们的长期目标是开发针对癌细胞有缺陷的小分子疗法 在剪接途径中。为了实现我们的目标，我们设计了两个具体目标：1）优化 U2AF1抑制剂通过将计算机辅助设计与化学合成的抑制剂集成； 2）研究疗法 U2AF1抑制剂使用体外和体内U2AF1MD/AML模型的影响。在AIM 1中，我们将改善 基于初步结构活动关系和选择性的U2AF1抑制剂的活性和选择性 SF1-8的数据通过整合化学合成，计算机辅助设计，生化测定和共同 晶体结构测定。在AIM 2中，我们将评估MDS/AML中U2AF1抑制剂的活动 细胞模型，分析用U2AF1抑制剂处理的细胞系中的转录组和剪接模式变化 并确定我们的抑制剂对异种小鼠模型中红细胞生成的影响。我们的申请是 创新而重要的是，因为它建立在我们发现U2AF1的热门歌曲的基础上，这是一个新兴的小说目标 与髓样恶性肿瘤的转化有关，并有可能建立新的 通过药物靶向突变的U2AF1细胞来治疗MDS/AML的治疗平台。