Targeting Nonsense-Mediated RNA Decay in Splicing Factor Mutant Myeloid Malignancies.

靶向剪接因子突变骨髓恶性肿瘤中无义介导的 RNA 衰变。

• 批准号: 10751386
• 负责人: Claudia Cabrera
• 金额: $ 3.36万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10751386
• 关键词: Acute Myelocytic Leukemia; Alternative Splicing; Apoptosis; Biological Assay; Biological Markers; Biological Models; Bone Marrow; Cancer cell line; Cell Death; Cell Line; Cell Survival; Cells; Chronic Myelomonocytic Leukemia; Clinical; Clonal Hematopoietic Stem Cell; Combined Modality Therapy; Congenic Mice; DNA; DNA Damage; DNA Repair; Data; Development; Disease; Dose; Drug Combinations; Dysmyelopoietic Syndromes; Dysplasia; Engraftment; Future; Gene Mutation; Genes; Genetically Engineered Mouse; Genomic Instability; Goals; Hematologic Neoplasms; Heterozygote; Hybrids; Hypersensitivity; In Vitro; Ineffective Hematopoiesis; Lead; Malignant Neoplasms; Mammals; Measures; Mediating; Messenger RNA; Modeling; Molecular; Molecular Target; Mus; Mutant Strains Mice; Mutation; Myeloproliferative disease; Pathway interactions; Patients; Pattern; Pharmaceutical Preparations; Pharmacodynamics; Pharmacological Treatment; Phosphorylation; Poly(ADP-ribose) Polymerase Inhibitor; Prevalence; Process; Production; Proliferating; Protein Isoforms; Protein Kinase; Proteins; RNA; RNA Decay; RNA Helicase; RNA Splicing; Recurrence; Reporting; Resolution; Role; SRSF2 gene; Sampling; Single-Stranded DNA; Spliceosomes; Structure; Terminator Codon; Testing; Therapeutic; Transcript; Translating; acute myeloid leukemia cell; attenuation; cancer cell; cancer therapy; candidate identification; cell type; cytopenia; efficacy study; experimental study; gene repair; genetically modified cells; in vivo; in vivo Model; inhibitor; innovation; mutant; novel; novel strategies; novel therapeutic intervention; peripheral blood; pharmacologic; pre-clinical; premature; resistance mechanism; side effect; targeted treatment; therapeutic evaluation; transcriptome sequencing

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized by peripheral blood cytopenias, bone marrow dysplasia, and ineffective hematopoiesis. Approximately 50% of MDS, 60% chronic myelomonocytic leukemia (CMML), 20% of acute myeloid leukemia (AML) harbor heterozygous mutations in spliceosome factor genes such as SF3B1, U2AF1, SRSF2 and ZRSR2. Although many studies have shown that mutations in splicing factor genes lead to distinct patterns of aberrant splicing, no specific alternatively spliced isoform has been demonstrated to directly cause MDS. However, aberrations in splicing induced by splicing factor gene mutations create a vulnerability in MDS cells. Our group and others showed that cells harboring spliceosome gene mutations have increased sensitivity to pharmacological perturbation of the spliceosome by splicing modulator drugs. The sensitivity of spliceosome mutant cells to further splicing perturbations raises the possibility that they are vulnerable to accumulation of misspliced transcripts. A large portion of the misspliced RNAs caused by spliceosome mutations or splicing modulator treatment are nonsense mRNAs that harbor premature termination codons (PTCs). These nonsense mRNAs, which may cause deleterious effects if translated, are normally degraded by a RNA surveillance pathway called nonsense-mediated RNA decay (NMD). The prevalence of nonsense mRNAs in cancer cells with spliceosome mutations leads us to hypothesize that mutant cells will be more sensitive to NMD attenuation due to the role of NMD in the clearance of nonsense mRNAs that can be detrimental. Preliminary data from our group indicate that NMD disruption (using a SMG1 inhibitor [SMG1i]) preferentially kills cancer cells expressing different splicing factor gene mutations. This cell death is associated with the induction of R-loops and DNA damage. Building on preliminary studies, we propose to test the therapeutic potential of NMD inhibition in selective killing of spliceosome mutant cancer cells using in vivo models and define the underlying mechanism for the hypersensitivity of spliceosome mutant cells to NMD attenuation. In Specific Aim 1, we will test the therapeutic potential of NMD inhibition to selectively kill spliceosome mutant cancer cells using in vivo models. We will engraft primary mouse AML cells in congenic mice and test whether in vivo treatment with a highly specific inhibitor of SMG1 (SMG1i), the only known protein kinase that regulates the NMD pathway, can selectively kill cancer cells with spliceosome mutations. We will further establish the therapeutic potential of targeting NMD by combining SMG1i with ATR or PARP inhibitors, DNA damage repair proteins that are activated in splicing factor mutant cells. In Specific Aim 2, we will define the molecular mechanism for the sensitivity of spliceosome mutant cells to NMD attenuation. We will identify candidate NMD targets whose levels are modulated by SMG1i or mutant splicing factors, potentially nominating downstream functional targets that could be modulated for cancer treatment. Collectively, this project will nominate therapies to treat MDS and AML with splicing factor mutations.

骨髓增生异常综合征（MDS）是一组异质性克隆性造血干细胞疾病 其特征在于外周血细胞减少、骨髓发育不良和无效造血。 约50%的MDS、60%的慢性粒单核细胞白血病（CMML）、20%的急性髓性白血病 (AML)在剪接体因子基因如SF3B1、U2AF1、SRSF2和ZRSR2中具有杂合突变。 尽管许多研究表明剪接因子基因的突变会导致不同模式的异常表达， 尽管存在选择性剪接，但没有特异性选择性剪接亚型被证明直接导致MDS。然而，在这方面， 由剪接因子基因突变诱导的剪接畸变在MDS细胞中产生了脆弱性。我们集团 其他研究表明，携带剪接体基因突变的细胞对 剪接调节剂药物对剪接体的药理学扰动。剪接体的敏感性 突变细胞进一步剪接扰动的可能性，他们是脆弱的积累， 拼接错误的转录本。大部分错误剪接的RNA是由剪接体突变或剪接引起的， 调节剂处理的mRNA是具有提前终止密码子（PTC）的无义mRNA。这些无稽之谈 mRNA，如果翻译可能会导致有害影响，通常通过RNA监视降解 无义介导的RNA衰变（NMD）。无义mRNAs在癌细胞中的流行， 剪接体突变使我们假设突变细胞将对NMD衰减更敏感， NMD在清除可能有害的无义mRNA中的作用。我们小组的初步数据 表明NMD破坏（使用SMG1抑制剂[SMG1i]）优先杀死表达不同 剪接因子基因突变。这种细胞死亡与R环的诱导和DNA损伤有关。 在初步研究的基础上，我们建议测试NMD抑制在选择性杀伤中的治疗潜力。 剪接体突变癌细胞的体内模型，并定义了潜在的机制， 剪接体突变细胞对NMD减毒超敏性。在具体目标1中，我们将测试治疗 使用体内模型，NMD抑制选择性杀死剪接体突变癌细胞的潜力。我们将嫁接 原代小鼠AML细胞，并测试是否在体内用高度特异性的AML抑制剂治疗。 SMG1（SMG1i）是唯一已知的调节NMD通路的蛋白激酶，可以选择性地杀死癌细胞 剪接体突变。我们将进一步建立针对NMD的治疗潜力， SMG1i与ATR或PARP抑制剂，在剪接因子突变体中激活的DNA损伤修复蛋白 细胞在特定目标2中，我们将定义剪接体突变细胞敏感性的分子机制 NMD衰减。我们将确定其水平受SMG1i或突变体调节的候选NMD靶标。 剪接因子，可能提名下游功能靶点，可调节癌症 治疗总的来说，该项目将提名治疗剪接因子突变的MDS和AML的疗法。