The role and mechanism of FTO in leukemogenesis and drug response

项目总结（摘要）： 背景：FTO是第一个N6-甲基腺苷RNA去甲基化酶， 对m6 A修饰的调节功能的研究产生了巨大的兴趣。尽管气候变化的严重影响 m6 A在各种基本生物过程中的修饰，m6 A的功能（和分子机制） FTO在癌症中的作用，如急性髓性白血病（AML），还有待研究。AML是最常见的 常见和致命的造血系统恶性肿瘤。尽管风险分层和治疗有所改善- 然而，在适应策略的情况下，>70%的AML患者由于耐药性而不能存活超过5年。因此， 更好地了解AML发病机制和药物反应的分子机制，这可能导致 开发有效的新型治疗策略来治疗AML。我们的数据表明，FTO可能发挥了 在MLL重排AML的发病机制和t（15;17）AML的药物反应中起关键的致癌作用。我们 显示FTO在携带t（11 q23）/MLL重排、t（15;17）、NPM 1突变的AML中高度表达， 和/或FLT 3-ITD，即FTO-高AML，其对全反式维甲酸（ATRA）更敏感，和/或 三氧化二砷（ATO）治疗比其他AML亚型。基于ATRA/ATO的分化治疗具有 将t（15;17）AML从高致命性疾病转变为高治愈性疾病。然而，FTO的作用和 高FTO AML的发病机制和药物反应的潜在分子机制尚不清楚。 目的/假设：我们假设FTO作为一个主要的m6 A擦除器，在两个过程中都起着关键作用。 通过表观遗传学调节其靶点的表达，研究FTO高AML的发病机制和药物反应。 具体目的：（1）探讨FTO在FTO高表达的形成和维持中的作用 AML;（2）确定FTO的关键直接靶点和FTO高AML中的调控机制;以及（3） 确定FTO在高FTO AML对ATRA和/或 ATO治疗。 研究设计：1）采用Fto基因敲除结合小鼠骨髓移植的模型 (BMT)白血病模型，以研究FTO在发展和维持中的病理功能 FTO-高AML的各种亚型和相关白血病干细胞/起始细胞的自我更新 (LSCs/低收入国家）。2)我们将通过整合m6 A分布数据与 FTO-RNA相互作用数据，并将破译FTO转录后作用的分子机制。 调节其直接靶基因的表达，然后对 FTO在高FTO AML发病机制中的作用。3)我们将使用小鼠BMT白血病模型和患者- 衍生的异种移植模型，以确定FTO在移植中的作用和潜在的分子机制。 FTO-高AML对ATRA和/或ATO治疗的反应。FTO的关键靶基因及相关基因 将鉴定负责FTO-高AML对ATRA和/或ATO治疗的应答的途径。

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.