Cellular and molecular basis of microRNA-29a Induced Acute Myeloid Leukemia

microRNA-29a 诱导的急性髓系白血病的细胞和分子基础

• 批准号: 8732609
• 负责人: CHRISTOPHER Y PARK
• 金额: $ 35.59万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-10 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8732609
• 关键词: Acute Myelocytic Leukemia; Apoptosis; Appearance; Biological Assay; Biological Models; Blood Cells; Cell Cycle; Cell physiology; Cell surface; Cells; Ceramides; Clinical; Commit; Data; Development; Disease; Ectopic Expression; Epigenetic Process; Event; Exhibits; Gene Targeting; Genes; Genetic; Gold; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Human; Lesion; MLL-AF9; Maintenance; Malignant Neoplasms; Mediator of activation protein; MicroRNAs; Modeling; Molecular; Mus; Mutate; Mutation; Myelogenous; Myeloid Leukemia; Myeloproliferative disease; Outcome; Pathogenesis; Phase; Phenotype; Population; Process; RUNX1 gene; Regulation; Relative (related person); Role; Sampling; Somatic Mutation; Staging; Stem cells; Study models; Testing; Transplantation; Work; base; experience; genetically modified cells; human disease; in vivo; insight; leukemia; leukemic stem cell; leukemogenesis; mouse model; new therapeutic target; progenitor; public health relevance; self-renewal; stem; stem cell population; therapeutic target; transcriptome sequencing

DESCRIPTION (provided by applicant): Cellular and molecular basis of microRNA-29a induced acute myeloid leukemia. Acute myeloid leukemia (AML) arises from the accumulation of genetic and/or epigenetic changes in immature hematopoietic cells. While leukemogenesis involves multiple steps including initiation, progression, transformation, and maintenance, studying these processes in human disease presents many practical challenges; however, well-characterized mouse models of AML afford the opportunity to study each of them due to the relative ease of genetically modifying cells and testing cellular function in a variety of in vitroand in vivo assays. While AML arises from immature hematopoietic cells, the exact cell that initiates disease or ultimately transforms into the leukemia stem cell (LSC) is unclear. We previously showed that microRNA-29a (miR-29a) is highly expressed in human HSC and AML LSC, and that ectopic expression of miR-29a in mouse BM cells is sufficient to induce a myeloproliferative neoplasm (MPN)-like disease that progresses to AML. We characterized miR-29a induced disease and showed that self-renewing committed progenitors arise prior to the development of AML and that miR-29a induced AMLs contain LSCs that can be prospectively isolated based on the expression of specific cell surface markers. Although the precise role of the self-renewing progenitors has not been defined, their appearance raises the intriguing possibility that aberrant acquisition of self-renewal by committed progenitors may be an early event in AML pathogenesis. Overall, these data demonstrate that the miR-29a induced AML model is a robust and experimentally tractable model for studying AML pathogenesis. We propose to characterize miR-29a's roles during AML development and to elucidate the molecular basis of miR-29a's regulation of self-renewal in LSCs and aberrantly self-renewing progenitors. We will determine if miR-29a is required for leukemogenesis utilizing our newly developed miR-29a deficient mouse model as well as various mouse models of AML. We will identify the cell population/s that become transformed during miR- 29a driven leukemogenesis, and we will also test the contribution of two miR-29a targets, Dnmt3a and Smpd3 (genes also recurrently mutated in human AML) to miR-29a induced phenotypes. To identify potential genes or mutations that may cooperate with miR-29a to induce leukemia, we will perform RNA-Seq on LSCs and aberrantly self-renewing progenitors. Finally, we will leverage our experience working with the miR-29a induced AML model as well as with primary human AML samples to evaluate the role of miR-29a in LSC function in the serial transplantation setting, the gold-standard assay for self-renewal. Ultimately, we expect these studies to generate new insights into the role of miR-29a in AML, define the molecular mechanisms of miR-29a's actions in pre-leukemic intermediates (including the molecular basis for self-renewal), and determine whether miR-29a or its downstream mediators may serve as potential therapeutic targets in AML.

描述（由申请人提供）：microRNA-29a诱导急性髓系白血病的细胞和分子基础。急性髓系白血病 (AML) 是由未成熟造血细胞中遗传和/或表观遗传变化的积累引起的。虽然白血病发生涉及多个步骤，包括起始、进展、转化和维持，但研究人类疾病中的这些过程提出了许多实际挑战；然而，由于基因修饰细胞和在各种体外和体内检测中测试细胞功能相对容易，充分表征的 AML 小鼠模型提供了研究每种模型的机会。虽然 AML 起源于未成熟的造血细胞，但引发疾病或最终转化为白血病干细胞 (LSC) 的确切细胞尚不清楚。我们之前表明，microRNA-29a (miR-29a) 在人类 HSC 和 AML LSC 中高表达，并且 miR-29a 在小鼠 BM 细胞中的异位表达足以诱导骨髓增殖性肿瘤 (MPN) 样疾病，并进展为 AML。我们对 miR-29a 诱导的疾病进行了表征，并表明自我更新的定型祖细胞在 AML 发生之前出现，并且 miR-29a 诱导的 AML 含有可以根据特定细胞表面标志物的表达前瞻性分离的 LSC。尽管自我更新祖细胞的确切作用尚未明确，但它们的出现提出了一种有趣的可能性，即定向祖细胞异常获得自我更新可能是 AML 发病机制的早期事件。总体而言，这些数据表明 miR-29a 诱导的 AML 模型是研究 AML 发病机制的稳健且实验上易于处理的模型。我们建议描述 miR-29a 在 AML 发展过程中的作用，并阐明 miR-29a 在 LSC 和异常自我更新祖细胞中调节自我更新的分子基础。我们将利用我们新开发的 miR-29a 缺陷小鼠模型以及各种 AML 小鼠模型来确定 miR-29a 是否是白血病发生所必需的。我们将鉴定在 miR-29a 驱动的白血病发生过程中发生转化的细胞群，我们还将测试两个 miR-29a 靶标 Dnmt3a 和 Smpd3（在人类 AML 中也经常突变的基因）对 miR-29a 诱导表型的贡献。为了识别可能与 miR-29a 协同诱导白血病的潜在基因或突变，我们将对 LSC 和异常自我更新的祖细胞进行 RNA 测序。最后，我们将利用我们在 miR-29a 诱导的 AML 模型以及原代人类 AML 样本方面的经验，评估 miR-29a 在连续移植环境中 LSC 功能中的作用，这是自我更新的金标准测定。最终，我们期望这些研究能够对 miR-29a 在 AML 中的作用产生新的见解，定义 miR-29a 在白血病前期中间体中作用的分子机制（包括自我更新的分子基础），并确定 miR-29a 或其下游介质是否可以作为 AML 的潜在治疗靶点。