No-nonsense approach to treat myeloid malignancies with ASXL1 nonsense mutations

治疗具有 ASXL1 无义突变的骨髓恶性肿瘤的严肃方法

基本信息

批准号：
8690401
负责人：
Mingjiang Xu
金额：
$ 16.97万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-03 至 2014-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8690401
关键词：
Acute Myelocytic Leukemia Alleles Amino Acids Aminoglycosides Animal Model Attenuated C-terminal Cell physiology Cells Cessation of life Chromosomes Clinical Trials Comb animal structure Cystic Fibrosis Cystic Fibrosis Transmembrane Conductance Regulator Data Development Disease Dysmyelopoietic Syndromes Dystrophin Frequencies Generations Genes Gentamicins Goals Hematologic Neoplasms Hematopoietic Histone H3 Human In Vitro Intellectual functioning disability Length Location Maps Mediating Methylation Monitor Mus Muscular Dystrophies Mutate Mutation Myelofibrosis Myelogenous Myeloproliferative disease N-terminal Nonsense Codon Nonsense Mutation Opitz syndrome Pathogenesis Patients Peptides Phenotype Placebos Plants Population Protein Truncation Proteins Reading Role Sampling Specimen Stem cells Terminator Codon Testing Therapeutic Translations base homeodomain in vivo innovation leukemia loss of function malformation mouse model novel outcome forecast overexpression premature prevent protein purification public health relevance reading ability sex stem success transgene expression treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Read-through compounds (RTCs) are capable of promoting ribosomal read-through of premature termination codons (PTCs), resulting in substitution of the PTC with an amino acid and generation of full-length protein product. The RTCs include aminoglycosides (such as gentamicin) and non-aminoglycoside (such as ataluren and RTC13) compounds, which are specific for PTCs and do not interfere with normal stop codons. These RTCs have been shown to have read-through activity on nonsense mutations in the CFTR and the dystrophin genes in both cultures and animal models. Intriguingly, clinical trials in patients with nonsense mutation muscular dystrophy and cystic fibrosis showed that RTCs induced some expression of functional, previously missing, proteins in both diseases and had some therapeutic benefits. Additional sex comb-like 1 (ASXL1) is mutated at high frequencies in multiple forms of myeloid malignancies, including MDS, MPN, CMML, and AML. De novo ASXL1 mutations cause Bohring-Opitz syndrome. Mutations in ASXL1 are nonsense/frameshift, leading to loss-of-function by truncating the critical PHD domain. Mutations in ASXL1 are associated with poor prognosis. Approximately 1/3 of the myeloid malignancy cases with ASXL1 mutations are nonsense, which are appealing targets for PTC-based read- through. In this application, we will explore the hypothesis that RTCs are capable of reversing ASXL1-PTCs and induce adequate amount of full-length, functional ASXL1 expression in hematopoietic stem/progenitor cells (HSCs/HSPCs), therefore attenuating the ASXL1-deficiency/haploinsufficiency mediated abnormal HSC/HPC function and hematological phenotype. Three specific aims are proposed to test this hypothesis. Aim 1: To determine the ability of RTCs (gentamicin, ataluren and RTC13) to reverse Asxl1-PTCs and yield adequate amount of full-length, functional Asxl1 expression in various hematopoietic cell populations from Asxl1-PTCTg;MxCre mice. Aim 2: To assess the therapeutic potential of RTCs by examining if RTC treatment is capable of preventing or curing the Asxl1-deficiency mediated pathogenesis of myeloid malignancies in Asxl1f/f;MxCre;Asxl1-PTCTg mice (inducible Asxl1-inactivation with simultaneous Asxl1-PTC transgene expression). Aim 3: To validate the therapeutic potential of RTCs using primary cells from myeloid malignancy patients with ASXL1 nonsense mutations. We will determine the ability of RTCs in promoting ribosomal read- through of different ASXL1-PTCs (TGA, TAA, TAG) in various hematopoietic cell populations from myeloid malignancy patients with ASXL1 nonsense mutations. We will examine if RTC treatment is capable of correcting/attenuating the abnormal cellular function of myeloid malignancy HSC/HPCs with ASXL1 nonsense mutations in NSG mice. Success of these studies will advance this novel treatment strategy into not only ASXL1-PTC diseases, but also many hematological malignancies due to nonsense mutation-mediated early termination of translation.

描述（由申请人提供）：读取化合物（RTC）能够促进过早终止密码子（PTC）的核糖体读取，从而用氨基酸代替PTC，并产生全长蛋白质产品。 RTC包括氨基糖苷（例如庆大霉素）和非氨基糖苷（例如Ataluren和RTC13）化合物，这些化合物对PTC具有特异性，并且不会干扰正常的停止密码子。这些RTC已被证明对培养物和动物模型中CFTR和肌营养不良蛋白基因的胡说八道突变具有读入活性。有趣的是，对肌肉营养不良和囊性纤维化的无义突变患者进行的临床试验表明，RTC在疾病中诱导了功能性的，以前缺失的蛋白质，并且具有一些治疗益处。额外的性梳状1（ASXL1）以高频以多种形式的髓样恶性肿瘤进行突变，包括MDS，MPN，CMML和AML。从头asxl1突变引起Bohring-Opitz综合征。 ASXL1中的突变是胡说八道/移码，通过截断临界PHD域而导致功能丧失。 ASXL1中的突变与预后不良有关。 ASXL1突变的髓样恶性肿瘤中约有1/3是胡说八道，这对基于PTC的读取具有吸引力。在此应用中，我们将探讨以下假设：RTC能够逆转ASXL1-PTC并诱导造血性干/祖细胞（HSCS/HSPC）中足够的全长功能性ASXL1表达，从而减弱ASXL1缺乏效率/heapoipers hemporied abncipal and hsc and/hsclemant和hsc的hsclotic and anc，提出了三个特定目标来检验这一假设。目标1：确定RTC（庆大霉素，ataluren和rtc13）逆转ASXL1-PTC并产生来自ASXL1-PTCTG各种造血细胞群体中的全长功能性ASXL1表达的能力。目的2：通过检查RTC治疗是否能够防止或治愈ASXL1F/F; MXCRE; ASXL1-PTCTG小鼠（syxl1-ptctg小鼠）（可识别asxl1 inactivivation a asxl1-inactivation sancectection as s ansxl1- transgene as trandcce），来评估RTC的治疗潜力，以预防或治愈ASXL1缺乏介导的髓样恶性肿瘤的发病机理。目标3：使用ASXL1废话突变的髓样恶性肿瘤患者的原代细胞验证RTC的治疗潜力。我们将确定RTC通过来自ASXL1废话突变的髓样恶性肿瘤患者的各种造血性恶性肿瘤患者的不同ASXL1-PTC（TGA，TAA，TAG）促进核糖体读数的能力。我们将检查RTC治疗是否能够纠正/衰减NSG小鼠中ASXL1废话突变的髓样恶性肿瘤HSC/HPC的异常细胞功能。这些研究的成功将使这种新颖的治疗策略不仅将ASXL1-PTC疾病推向，而且还将由于胡说八道突变介导的早期翻译的早期终止而引起的许多血液学恶性肿瘤。