Epigenetic regulation by microRNA of MDS pathogenesis

MicroRNA对MDS发病机制的表观遗传调控

• 批准号: 8611386
• 负责人: Keisuke Ito
• 金额: $ 25.05万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8611386
• 关键词: 3' Untranslated Regions; Ablation; Affect; Attenuated; Biogenesis; Bioinformatics; Biological Assay; Bone Marrow Cells; Cell Line; Cell Proliferation; Cell physiology; Cells; Clinic; Clinical; Clinical Data; Clinical Trials; Custom; DNA Methylation; Data; Data Set; Disease; Down-Regulation; Dysmyelopoietic Syndromes; Ectopic Expression; Epigenetic Process; Event; Evolution; Exhibits; Functional RNA; Gene Targeting; Genes; Genetic; Goals; Health; Hematologic Neoplasms; Hematology; Hematopoiesis; Hematopoietic; Hematopoietic Stem Cell Transplantation; Hematopoietic System; Hematopoietic stem cells; Human; Hydroxylation; In Vitro; Ineffective Hematopoiesis; Injury; Knockout Mice; Lead; Leukemic Cell; Link; Luciferases; Maintenance; Malignant - descriptor; Messenger RNA; MicroRNAs; Molecular; Molecular Abnormality; Multiple Myeloma; Mus; Myeloid Leukemia; Myeloproliferative disease; Nuclear; Oncogenic; Onset of illness; Outcome; Pathogenesis; Pathology; Pathway interactions; Patients; Penetrance; Personal Satisfaction; Phenotype; Play; Porifera; Pre-Clinical Model; Proteins; Proto-Oncogenes; Regulation; Regulatory Element; Reporter; Repression; Research; Research Design; Role; Safety; Sampling; Specimen; Stem cells; Supportive care; Survival Rate; Symptoms; Techniques; Testing; Therapeutic; Time; Tissues; Transgenic Mice; Transplantation; Work; Xenograft Model; blood treatment; cohort; effective therapy; genetic manipulation; genome-wide; in vivo; leukemia; leukemogenesis; mouse model; novel; novel therapeutic intervention; oncology; overexpression; preclinical study; programs; public health relevance; self-renewal; stem; stem cell biology; stem cell niche; therapeutic target; tumorigenesis

ABSTRACT Myelodysplastic syndrome (MDS) is an incurable stem cell disorder that often progresses to myeloid leukemia. An abnormal epigenetic modulation has been highlighted as playing a crucial part in the pathogenesis, progress, and evolution of this disorder. To date, effective therapy for MDS has proved elusive, with supportive care used to ameliorate symptoms, and hematopoietic stem cell transplantation the only available curative option. MicroRNAs have recently been implicated in hematological malignancies through their inhibition of the expression of specific target genes. In this context, we have identified an oncogenic microRNA that enhances the self-renewal of stem cells and remodels the epigenetic landscape toward hematological malignancies. To better understand through its activity the key pathways involved in stem cell biology and MDS pathogenesis, we propose the following Specific Aims: 1. Determine how TET2 directly contributes to function of an oncogenic microRNA in hematopoiesis We have generated transgenic mice conditionally expressing this newly-identified oncogenic microRNA in the hematopoietic compartment, which in turn exhibits lower levels of ten-eleven translocation gene 2 (TET2) and global 5-hydroxymethylcytosine than control cells. Bioinformatics analyses have consistently identified TET2 as a potential target of this microRNA, whose expression was directly anti-correlated with the levels of TET2 in our large-cohort data set of patients with MDS, leading us to hypothesize that TET2 is its key target. The current proposal aims to elucidate the effect of ectopic expression of TET2 on the hematopoietic phenotypes induced by this microRNA both in vivo and in vitro. We expect our studies will provide a rationale for the therapeutic potential of targeting TET2 for the treatment of hematological malignancies. 2. Test the therapeutic potential of microRNA inhibition in preclinical models of MDS We have shown a direct correlation between aberrant expression of this microRNA and poor MDS survival rates. Our preliminary findings demonstrated in vitro that blocking this microRNA reduces leukemogenicity in mouse primary leukemic cells and in human leukemia cell lines, accompanied by elevation of TET2, with minimal injury to normal murine hematopoieisis. In this aim, we propose to assess the safety and efficacy of inhibition of microRNA in human primary leukemia samples. We will integrate these findings with the data of ongoing pre-clinical trials in faithful mouse models of myelodysplastic syndrome, and will finally explore the potential to initiate formal clinical trial towards effective eradication of myelodysplastic syndrome. 3. To elucidate mechanistically the key target genes regulated by the microRNA-TET2 pathway: To further understand the consequences of repression of TET2 protein by the microRNA in hematopoiesis, we will examine the effects of aberrant microRNA-TET2 cross-talk on putative targets of TET2 protein. We will focus our analysis on the genetic manipulation of these genes, both in vivo and in vitro, in murine hematopoietic stem cells from transgenic mice, to observe the subsequent effects on MDS pathogenesis induced by microRNA. These proposed studies will not only identify microRNA as a potent proto-oncogene, but will also define aberrations in the microRNA-TET2 regulatory network as one of the most frequent events in hematological malignancies, with important therapeutic implications. This work will be conducted with the support of the following experts; Drs. David E. Avigan (Hematology/Oncology), Jan Vijg (Genetics, Epigenetics and microRNA biogenesis), Julie Teruya-Feldstein (Hemato-pathology), and Toshio Suda (Stem Cells). Importantly, Dr. Paul S. Frenette (Stem Cell niche) is closely supporting our research program along with Dr. Arthur Skoultchi (Epigenetic reprogramming in Hematology).

抽象的 骨髓增生性综合征（MDS）是一种无法治愈的干细胞疾病，通常会发展为髓样白血病。 异常的表观遗传调节被强调为在发病机理，进展， 和这种疾病的进化。迄今 改善症状，造血干细胞移植是唯一可用的治疗方法。 microRNA最近通过抑制血液系统恶性肿瘤。 特定靶基因的表达。在这种情况下，我们已经确定了一种致癌microRNA，可以增强 干细胞的自我更新并重塑了表观遗传景观，向血液学恶性肿瘤。更好 通过其活性了解干细胞生物学和MDS发病机理中涉及的关键途径，我们 提出以下具体目标： 1。确定TET2如何直接有助于造血中致癌性microRNA的功能 我们已经产生了有条件地表达这种新鉴定的致癌microRNA的转基因小鼠 造血区室又显示出较低的十个易位基因2（TET2） 与对照细胞相比，全球5-羟基甲苯二甲基胞嘧啶。生物信息学分析始终确定 TET2作为该microRNA的潜在靶标，其表达直接抗相关 TET2在我们的大型MDS患者数据集中，导致我们假设TET2是其关键目标。 当前的建议旨在阐明TET2异位表达对造血的影响 该microRNA在体内和体外诱导的表型。我们预计我们的研究将提供理由 对于靶向TET2治疗血液系统恶性肿瘤的治疗潜力。 2。测试MDS中microRNA抑制的治疗潜力 我们已经显示了该microRNA异常表达与MD差的异常表达之间的直接相关性 费率。我们的初步发现表明，在体外阻止了这种microRNA，降低了白血病性 小鼠原发性白血病细胞和人类白血病细胞系，伴随着TET2的升高 正常鼠造血症的最小损伤。在此目标中，我们建议评估 在人原发性白血病样品中抑制microRNA。我们将将这些发现与 在忠实的骨髓增生综合征的忠实鼠标模型中正在进行的临床前试验，并最终将探索 有效地消除骨髓增生综合征的可能进行正式临床试验的潜力。 3。为机械阐明由MicroRNA-TET2途径调节的关键靶基因： 为了进一步了解造血中microRNA对TET2蛋白抑制的后果， 我们将检查异常MicroRNA-TET2串扰对TET2蛋白推定靶标的影响。我们 将我们的分析集中在鼠类体内和体外的这些基因的基因操纵上 来自转基因小鼠的造血干细胞，观察随后对MDS发病机理的影响 由microRNA诱导。 这些提出的研究不仅将识别microRNA是有效的原始癌基因，而且还将定义 MicroRNA-TET2调节网络中的畸变是血液学中最常见的事件之一 恶性肿瘤，具有重要的治疗意义。 这项工作将在以下专家的支持下进行；博士。大卫·E·阿维根（David E. Avigan） （血液学/肿瘤学），Jan Vijg（遗传学，表观遗传学和microRNA生物发生），朱莉·特鲁亚·费尔德斯坦（Julie Teruya-Feldstein） （血清病理学）和Toshio suda（干细胞）。重要的是，Paul S. Frenette博士（干细胞小众）密切 与Arthur Skoultchi博士一起支持我们的研究计划（血液学中的表观遗传重编程）。