Development of Next-Generation Macrocyclic Histone Deacetylase Inhibitors

下一代大环组蛋白脱乙酰酶抑制剂的开发

• 批准号: 388454995
• 负责人: Dr. Martin Roatsch
• 金额: --
• 依托单位: Institut for Lægemiddeldesign og Farmakologi
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/388454995?language=en
• 关键词: Development; Next; Generation; Macrocyclic; Histone

Epigenetic mechanisms play a vital role in the regulation of gene expression and determine, which genes are expressed by which cells and at what times. This occurs both in healthy and, when aberrantly regulated, diseased cells. These mechanisms are manifested in chemical modifications both to DNA itself as well as to histone proteins, around which DNA is wrapped. “Eraser” enzymes that remove such marks like e.g. zinc-dependent histone deacetylases (HDACs) have been recognized as emerging drug targets, in particular in oncology. Some potent, yet unselective, inhibitors have already reached the clinic.This project aims at the development of novel inhibitors of this enzyme class based on the scaffold of azumamides, a family of naturally occurring cyclotetrapeptides. The inhibitors that will be generated in this project will investigate a novel mode of action, which does not rely on strong active site metal binding, but on disruption of protein-protein interactions of HDACs with their protein partners. Isolation of class I HDACs from their multiprotein complexes also leads to drastically reduced enzymatic activity.Structural knowledge is available about HDACs in complex with their protein partners, which positions one amino acid residue of the azumamide inhibitors in close proximity to the protein-protein interaction interface. Through chemical modifications to this residue as well as to the metal-binding residue, a library of novel azumamide derivatives will be generated and tested for their HDAC inhibition. A conceptually new in vitro assay will be established, which investigates HDAC protein-protein interactions by fluorescence polarization. This can be used to demonstrate disruption of complex formation by these inhibitors. This heretofore unexplored mechanism of inhibition allows for the introduction of selectivity with regard to HDAC subfamilies or even individual isotypes as they each have different protein complex partners. Structure-guided iterative optimization of the novel azumamides in a systematic SAR study in feedback with data from biochemical testing will yield potent dual-mechanism inhibitors. By balancing of these two mechanisms, compounds can be generated with tunable potency and selectivity for one HDAC subtype over the others. Cell culture experiments will validate the antiproliferative properties on cancer cell lines and substrate-specific changes in acetylation.The use of tetrapeptidic inhibitors of epigenetic HDAC enzymes represents a unique alternative method to temporal gene regulation. As outlined, the designed dual-mechanism compounds will allow for simultaneous inhibition of enzyme activity as well as their scaffolding function in protein-protein complexes. The enhanced biological effects that can be expected from this have the potential to make these next-generation HDAC inhibitors valuable tool compounds for the characterization of the biological role of individual enzymes as well as potential drug candidates.

表观遗传机制在基因表达的调控中起着至关重要的作用，并决定哪些基因由哪些细胞在什么时间表达。这既发生在健康的细胞中，也发生在异常调节的病变细胞中。这些机制表现在对DNA本身以及DNA包裹的组蛋白的化学修饰中。去除这些标记的“橡皮擦”酶，例如锌依赖性组蛋白脱乙酰酶（HDAC），已被认为是新兴的药物靶标，特别是在肿瘤学中。一些有效的，但非选择性的抑制剂已经进入临床。本项目旨在开发基于azumamides（一种天然存在的环四肽家族）支架的此类酶的新型抑制剂。该项目中产生的抑制剂将研究一种新的作用模式，该模式不依赖于强活性位点金属结合，而是破坏HDAC与其蛋白质伴侣的蛋白质-蛋白质相互作用。从多蛋白复合物中分离I类HDACs也会导致酶活性急剧降低。关于HDACs与其蛋白质伴侣复合物的结构知识是可用的，其将阿珠酰胺抑制剂的一个氨基酸残基定位在蛋白质-蛋白质相互作用界面附近。通过对该残基以及金属结合残基的化学修饰，将产生新型阿珠酰胺衍生物的文库并测试其HDAC抑制。将建立一种概念上新的体外测定方法，通过荧光偏振研究HDAC蛋白质-蛋白质相互作用。这可用于证明这些抑制剂对复合物形成的破坏。这种迄今为止未探索的抑制机制允许引入关于HDAC亚家族或甚至单个同种型的选择性，因为它们各自具有不同的蛋白质复合物配偶体。在系统的SAR研究中，以生物化学测试数据为反馈，对新的azumamides进行结构指导的迭代优化，将产生有效的双重机制抑制剂。通过平衡这两种机制，可以产生对一种HDAC亚型具有可调效力和选择性的化合物。细胞培养实验将验证对癌细胞系的抗增殖特性和乙酰化底物特异性变化。使用表观遗传HDAC酶的四肽抑制剂代表了时间基因调控的独特替代方法。如所概述的，所设计的双机制化合物将允许同时抑制酶活性以及它们在蛋白质-蛋白质复合物中的支架功能。由此可以预期的增强的生物效应有可能使这些下一代HDAC抑制剂成为表征单个酶的生物作用以及潜在候选药物的有价值的工具化合物。