Characterising and targeting aberrant enhancer function in acute myeloid leukaemia (AML)

急性髓系白血病 (AML) 异常增强子功能的表征和靶向

• 批准号: MR/M010392/1
• 负责人: Brian Huntly
• 金额: $ 67.05万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FM010392%2F1
• 关键词: Characterising; targeting; aberrant; enhancer; function

Acute myeloid leukaemia (AML) is an aggressive haematological cancer. It is the most common acute leukaemia in Europe, with an incidence of 3-4 per 100,000 of the population. In addition, its incidence rises with age, therefore it will become an increasingly common problem as the general population ages. AML has a dismal overall survival rate of less than 30% and the mainstay of treatment aggressive, toxic, combination chemotherapy has remained ostensibly unchanged for the last 25 years. Novel therapies are therefore urgently required to improve treatment outcomes in AML. Where a greater knowledge of the mechanisms of disease have been uncovered, therapeutic gains have often been achieved. The most impressive example of this is the acute promyelocytic leukaemia subtype, where an understanding of the mechanisms that underlie this subtype has led to the development of novel therapies (All Trans Retionoic Acid, ATRA and arsenic trioxide) that can cure up to 90% of patients. Therefore, a better understanding of AML biology is a pre-requisite for the development of novel therapies to improve treatment outcomes.Recently, a number of studies have documented that AML is associated with abnormal expression of genes and we and others have shown that correction of these abnormal gene programmes, with drugs such as small molecule inhibitors, may be a promising therapy. The expression of genes varies greatly between different tissues in the body and these differences are regulated by DNA elements called enhancers. Enhancers regulate the expression of genes by communication with promoters (the DNA start sites of genes) in a tissue-specific manner, such that for a gene X, there may be a number of different enhancers that regulate the expression of X in different tissues such as blood, brain and skin. Enhancers are a often a long distance away from promoters and require 3-dimensional contact with promoters through the formation of DNA loops. The function of enhancers is in turn controlled and modelled by molecules called transcription factors and regulators of chromatin (DNA and its protein scaffold). Recent work has shown that enhancers, transcription factors (TF) and chromatin regulators are all recurrently and commonly mutated in AML. We therefore propose that abnormal enhancer function is causative in AML and that it may be possible to therapeutically target this abnormal function to correct abnormal gene expression programmes thereby switching off leukaemia.This proposal will address how enhancer usage and function differ during the evolution of AML from normal haematopoiesis, the process of normal blood formation. To allow us to model this prospectively, we will use mouse models with different combinations of AML-specific mutations that mimic different stages of the disease: normal, pre-leukaemic and frankly leukaemia stages. We will compare the presence, usage and function of enhancers between stages using the binding of specific proteins to DNA, a technique called ChIP-Seq. In addition, using another cutting-edge technique called Hi-C, we will map looping interactions between enhancers and promoters and how these differ by stage of disease. We will also measure the end output, that is expression of genes, detailing differences between the stages and how these correlate with enhancer usage. We will then compare these patterns to human leukaemia's that carry the same mutations. These data will allow us to identify the TF and chromatin regulators that control leukaemia specific enhancers. Our last objective will be to inhibit these factors, as a proof of concept that enhancer function may be a therapeutic target. We will use drug-like small molecular inhibitors and genetic techniques to alter the function of these regulators and will look for alterations of leukaemia growth and gene expression both in test tube experiments and live models of leukaemia.

急性髓性白血病（AML）是一种侵袭性血液系统癌症。它是欧洲最常见的急性白血病，发病率为每10万人中有3-4人。此外，其发病率随着年龄的增长而上升，因此随着一般人口的老龄化，它将成为一个越来越普遍的问题。AML的总生存率低于30%，治疗的主要手段是积极的、毒性的联合化疗，在过去的25年里表面上保持不变。因此，迫切需要新的疗法来改善AML的治疗结果。在对疾病机制有了更多了解的地方，往往就能取得治疗上的进展。最令人印象深刻的例子是急性早幼粒细胞白血病亚型，对该亚型机制的理解导致了新疗法（全反式维甲酸，ATRA和三氧化二砷）的开发，可以治愈高达90%的患者。因此，更好地了解AML生物学是开发新疗法以改善治疗结果的先决条件。最近，许多研究表明AML与基因异常表达有关，我们和其他人已经表明，用小分子抑制剂等药物纠正这些异常基因程序可能是一种有前途的治疗方法。基因的表达在体内不同组织之间差异很大，这些差异由称为增强子的DNA元件调节。增强子通过以组织特异性方式与启动子（基因的DNA起始位点）通信来调节基因的表达，使得对于基因X，可能存在许多不同的增强子，其调节X在不同组织（例如血液、脑和皮肤）中的表达。增强子通常距离启动子很远，并且需要通过形成DNA环与启动子进行三维接触。增强子的功能反过来由称为转录因子和染色质调节因子（DNA及其蛋白质支架）的分子控制和建模。最近的研究表明，增强子，转录因子（TF）和染色质调节因子都是复发性的，通常在AML中突变。因此，我们提出，异常的增强子功能是在AML的病因，它可能是有可能的治疗靶向这种异常的功能，以纠正异常的基因表达程序，从而关闭leukemia.This建议将解决如何增强子的使用和功能不同的AML从正常的造血，正常的血液形成的过程中的演变。为了使我们能够前瞻性地建立模型，我们将使用具有AML特异性突变的不同组合的小鼠模型，这些突变模拟疾病的不同阶段：正常，白血病前和白血病阶段。我们将使用特定蛋白质与DNA的结合（一种称为ChIP-Seq的技术）来比较不同阶段之间增强子的存在、使用和功能。此外，使用另一种称为Hi-C的尖端技术，我们将绘制增强子和启动子之间的循环相互作用以及这些相互作用在疾病阶段的差异。我们还将测量最终输出，即基因的表达，详细说明各个阶段之间的差异以及这些差异如何与增强子的使用相关。然后，我们将这些模式与携带相同突变的人类白血病进行比较。这些数据将使我们能够确定TF和染色质调节控制白血病特异性增强子。我们的最后一个目标是抑制这些因子，作为增强子功能可能是治疗靶点的概念证明。我们将使用药物样小分子抑制剂和遗传技术来改变这些调节剂的功能，并将在试管实验和白血病活体模型中寻找白血病生长和基因表达的改变。

项目成果

Ezh2 and Runx1 Mutations Collaborate to Initiate Lympho-Myeloid Leukemia in Early Thymic Progenitors.

Ezh2 和 Runx1 突变共同引发早期胸腺祖细胞的淋巴细胞白血病。

• DOI: 10.17863/cam.22956
• 发表时间: 2018
• 作者: Booth C

Ezh2 and Runx1 Mutations Collaborate to Initiate Lympho-Myeloid Leukemia in Early Thymic Progenitors

• DOI: 10.1016/j.ccell.2018.01.006
• 发表时间: 2018-02-12
• 期刊: CANCER CELL
• 影响因子: 50.3
• 作者: Booth, Christopher A. G.;Barkas, Nikolaos;Mead, Adam J.
• 通讯作者: Mead, Adam J.

BET inhibitor resistance emerges from leukaemia stem cells.

BET抑制剂耐药性来自白血病干细胞。

• DOI: 10.1038/nature14888
• 发表时间: 2015-09-24
• 期刊: Nature
• 影响因子: 64.8
• 作者: Fong CY;Gilan O;Lam EY;Rubin AF;Ftouni S;Tyler D;Stanley K;Sinha D;Yeh P;Morison J;Giotopoulos G;Lugo D;Jeffrey P;Lee SC;Carpenter C;Gregory R;Ramsay RG;Lane SW;Abdel-Wahab O;Kouzarides T;Johnstone RW;Dawson SJ;Huntly BJ;Prinjha RK;Papenfuss AT;Dawson MA
• 通讯作者: Dawson MA

Mll-AF4 Confers Enhanced Self-Renewal and Lymphoid Potential during a Restricted Window in Development.

• DOI: 10.1016/j.celrep.2016.06.046
• 发表时间: 2016-07-26
• 期刊: Cell reports
• 影响因子: 8.8
• 作者: Barrett NA;Malouf C;Kapeni C;Bacon WA;Giotopoulos G;Jacobsen SEW;Huntly BJ;Ottersbach K
• 通讯作者: Ottersbach K