Selective disruption of histone deacetylase complexes using protein interaction modulators

项目摘要 鉴定新型治疗剂的策略通常包括靶向与相关免疫应答相关的酶活性。 生物学途径，假设这种方法最有可能识别有效、安全和生物利用度 毒品这一概念特别适用于表观遗传干扰物的发展，如组蛋白 脱乙酰酶（HDAC）抑制剂或“HDACis”。所有七种FDA批准的HDAC都以类似的方式结合， 混杂的脱乙酰酶酶口袋。虽然这种“酶抑制剂”化合物被成功地使用， 但是它们在治疗T细胞淋巴瘤和多发性骨髓瘤方面仍然局限于其它类型的癌症。 目前可用的HDAC的主要局限性之一是，通过系统地靶向HDAC酶， 口袋，它们对负责调节不同的HDAC复合物几乎没有特异性。 基因的子集，因此，他们影响转录调控的大部分， 转录组我们的目标是开发一种替代模型，根据该模型，“蛋白质相互作用 调节剂”干扰HDAC亚复合物亚群中的特异性蛋白质相互作用，因此具有很大的 对经处理细胞的转录组的影响比常规HDACis更窄。这个问题的核心假设是 模型是，干扰细胞中特定的HDAC亚复合物而不是所有HDAC复合物可能导致 更窄的转录作用，但赋予有效的抗肿瘤作用（图1）。为了验证这一 假设，我们提出以下三个具体目标。 目标1。为了确定在何种程度上，小分子扰动的非酶亚基， HDAC复合物可以影响其抑制功能。我们的目标是确定一类新的HDAC 调节剂，而不是靶向酶口袋，会影响HDAC的其他更具体的功能， 配合物 目标二。为了比较HDAC非酶与酶促小分子的总体转录组学效应， 分子微扰我们中心假设的一个分支是， 复杂的调节剂，导致比用常规方法观察到的转录效应窄得多的转录效应， HDAC酶抑制剂。在这里，我们将确定HDAC亚复合物调节剂的转录组范围的影响， 来研究这些新化合物对转录组的影响范围有多大。 目标3：为了验证HDAC复合物的启动子占据扰动可以有效地 消除肿瘤发生表型。我们将测试在多大程度上干扰特定的HDAC亚复合物，而不是 比所有的细胞HDAC复合物，虽然导致更窄的转录效应， 赋予有效的抗肿瘤作用。 简而言之，我们提出，与传统HDAC抑制剂不同的是， 可以鉴定一类新的影响特定HDAC亚复合物的蛋白质相互作用调节剂。

Project Summary Strategies to identify novel therapeutics typically include targeting enzymatic activities involved in relevant biological pathways, with the assumption that this approach will most likely identify potent, safe, and bioavailable drugs. This concept is particularly relevant to the development of epigenetic perturbants such as histone deacetylase (HDAC) inhibitors, or “HDACis”. All seven FDA-approved HDACis bind in similar ways to promiscuous deacetylase enzymatic pockets. While such “enzymatic inhibitor” compounds are used successfully to treat T cell lymphomas and multiple myelomas, they remain limited in addressing other types of cancers. One of the major limitations of currently available HDACis is that, by systematically targeting HDAC enzymatic pockets, they show little specificity for various HDAC complexes responsible for the regulation of different subsets of genes, and consequently, they affect the transcriptional regulation of a large portion of the transcriptome. Our goal here is to develop an alternative model according to which “protein interaction modulators” perturb specific protein interactions in subsets of HDAC subcomplexes and thus have much narrower effects on the transcriptome of treated cells than conventional HDACis. The central hypothesis of this model is that perturbing specific HDAC subcomplexes rather than all HDAC complexes in a cell might result in much narrower transcriptional effects and yet confer potent anti-tumorigenic effects (Fig. 1). To test this hypothesis, we propose the three following specific aims. Aim 1. To determine the extent to which small-molecule perturbations of non-enzymatic subunits of HDAC complexes can affect their repressing functions. Our goal is to identify a new class of HDAC modulators, which, instead of targeting enzymatic pockets, would affect other, more specific functions of HDAC complexes. Aim 2. To compare global transcriptomic effects of HDAC non-enzymatic versus enzymatic small- molecule perturbations. One branch of our central hypothesis is that it should be possible to identify HDAC complex modulators that result in much narrower transcriptional effects than those observed with conventional HDAC enzymatic inhibitors. Here we will determine transcriptome-wide effects of HDAC subcomplex modulators to investigate how widely or narrowly these new compounds affect the transcriptome. Aim 3. To test the hypothesis that promoter occupancy perturbations of HDAC complexes can potently abrogate tumorigenic phenotypes. We will test to what extent perturbing specific HDAC subcomplexes rather than all cellular HDAC complexes, while resulting in much narrower transcriptional effects, might nevertheless confer potent anti-tumorigenic effects. In short, we propose that instead of affecting all HDAC activities in the cell as conventional HDAC inhibitors do, a new class of protein interaction modulators can be identified that affect specific HDAC subcomplexes.