The role and mechanism of FTO in leukemogenesis and drug response

项目摘要(摘要)： 背景：FTO被确认为第一个N6-甲基腺苷RNA去甲基酶 对研究m6A修饰的调节功能有极大的兴趣。尽管有严重的影响， M6A在各种基本生物学过程中的修饰，其功能(和分子机制) FTO在癌症中的作用，如急性髓系白血病(AML)，尚未得到研究。AML是世界上最大的 常见的和致命的血液系统恶性肿瘤。尽管改进了风险分层和治疗- 经过调整的策略，70%的AML患者由于耐药而无法存活5年以上。因此，它是至关重要的 为了更好地了解AML发病机制和药物反应的分子机制，可能导致 开发有效的治疗急性髓系白血病的新治疗策略。我们的数据表明，FTO很可能在 在MLL重排AML的发病机制和t(15；17)AML的药物反应中的关键致癌作用。我们 结果表明，FTO在携带t(11q23)/MLL重排、t(15；17)、NPM1突变的AML中高表达 和/或Flt3-ITD，即FTO-High AML，对全反式维甲酸(ATRA)和/或 三氧化二砷(ATO)治疗效果优于其他AML亚型。全反式维甲酸/全反式维甲酸的分化治疗 将t(15；17)AML从高度致命的疾病转变为高度可治愈的疾病。然而，FTO的作用和 FTO-高AML发病机制和药物反应的分子机制尚不清楚。 目标/假设：我们假设FTO作为主要的M6A擦除器，在这两种情况下都发挥着关键作用 表观遗传学调控FTO-高AML靶基因表达的发病机制及药物反应。 具体目标：(1)确定FTO在FTO-High的发展和维持中的作用 (2)确定FTO的关键直接靶点和高FTO的AMLS的调控机制(S)；(3) 确定FTO在FTO高的AML对ATRA和/或反应中的作用和潜在机制 ATO治疗。 研究设计：1)将FTO基因敲除模型与小鼠骨髓移植相结合 (BMT)白血病模型研究FTO在发育和维持过程中的病理作用 不同亚型高FTO-AML及其相关白血病干细胞/起始细胞的自我更新 (LSC/LIC)。2)我们将通过整合m6A分布数据和 FTO-RNA相互作用数据，并将在转录后破译FTO的分子机制(S 调控其直接靶基因的表达，随后对主要候选靶基因进行功能研究 FTO在高FTO-AMLS发病机制中的作用3)我们将使用小鼠骨髓移植白血病模型和患者- 衍生异种移植模型研究FTO在心脏移植中的作用及其分子机制 高FTO的AML对ATRA和/或ATO治疗的反应。FTO的关键靶基因及其相关基因 将确定负责FTO高AML对ATRA和/或ATO处理的反应的途径。

PROJECT SUMMARY (ABSTRACT): Background: The identification of FTO as the first N6-methyladenosine RNA demethylase have spurred immense interest in study of the regulatory functions of m6A modifications. Despite the critical impacts of the m6A modifications in various fundamental biological processes, the function (and molecular mechanism) of FTO in cancers, such as acute myeloid leukemia (AML), has yet to be studied. AML is one of the most common and fatal forms of hematopoietic malignancies. Despite the improved risk stratifications and treatment- adapted strategies, >70% of AML patients cannot survive over 5 years due to drug resistance. Thus, it is critical to better understand molecular mechanisms underlying pathogenesis and drug response of AML, which may lead to the development of effective novel therapeutic strategies to treat AML. Our data suggest that FTO likely plays a critical oncogenic role in the pathogenesis of MLL-rearranged AML and in drug response of t(15;17) AML. We show that FTO is highly expressed in AMLs carrying t(11q23)/MLL-rearrangements, t(15;17), NPM1 mutations and/or FLT3-ITD, namely FTO-high AMLs, which are more sensitive to all-trans-retinoic acid (ATRA) and/or arsenic trioxide (ATO) treatment than the other AML subtypes. ATRA/ATO-based differentiation therapy has transformed t(15;17) AML from a highly fatal disease to a highly curable one. However, the role of FTO and the underlying molecular mechanism in the pathogenesis and drug response of FTO-high AMLs are elusive. Objective/Hypothesis: We hypothesize that FTO, as a major m6A eraser, plays a critical role in both pathogenesis and drug response of FTO-high AMLs through epigenetically regulating expression of its targets. Specific Aims: (1) To determine the role of FTO in both development and maintenance of FTO-high AMLs; (2) To identify critical direct targets of FTO and the regulatory mechanism(s) in FTO-high AMLs; and (3) To determine the role and underlying mechanism of FTO in the response of FTO-high AMLs to ATRA and/or ATO treatment. Study Design: 1) We will use the Fto knockout model coupled with mouse bone marrow transplantation (BMT) leukemia models to investigate the pathological function of FTO in both development and maintenance of various subtypes of FTO-high AMLs and in the self-renewal of relevant leukemia stem/initiating cells (LSCs/LICs). 2) We will identify critical direct target genes of FTO by integrating m6A distribution data with FTO-RNA interaction data, and will decipher the molecular mechanism(s) by which FTO post-transcriptionally regulates expression of its direct target genes, followed by functional studies of the top candidate targets of FTO in the pathogenesis of FTO-high AMLs. 3) We will use both mouse BMT leukemia models and patient- derived xeno-transplantation models to determine the role and underlying molecular mechanism of FTO in the response of FTO-high AMLs to ATRA and/or ATO treatment. The critical target genes of FTO and relevant pathways that are responsible for the response of FTO-high AMLs to ATRA and/or ATO treatment will be identified.