利用蛋白酶体降解靶向嵌合体（PROTAC）探究I类组蛋白去乙酰酶（HDAC）开发高效选择性降解剂

Probing class I histone deacetylases (HDAC) with proteolysis targeting chimera (PROTAC) for the development of highly potent and selective degraders

BIOORGANIC CHEMISTRY

影响因子:4.7

分区:医学2区 / 有机化学1区生化与分子生物学2区

发表日期:2024 Dec

作者: Hany S Ibrahim, Menglu Guo, Sebatian Hilscher, Frank Erdmann, Matthias Schmidt, Mike Schutkowski, Chunquan Sheng, Wolfgang Sippl

DOI: 10.1016/j.bioorg.2024.107887

摘要

I类HDAC被认为是癌症的潜在靶点，原因在于它们在表观遗传修饰中的作用。开发新型高效且无毒的I类HDAC抑制剂的主要挑战在于选择性和药代动力学性能。PROTAC（Proteolysis Targeting Chimeras，蛋白降解靶向嵌合体）技术是一种新兴的药物开发方法，旨在通过促使目标蛋白（POI）降解而非抑制其活性，开启了制备具有高选择性和安全边际药物的新时代。此前，我们已报道了以氨基苯酰胺或羟酰胺基团为基的不同I类HDAC抑制剂。在本研究中，我们利用PROTAC技术，基于之前报道的抑制剂，开发了I类HDAC降解剂。合成了两系列氨基苯酰胺型和羟酰胺型PROTAC，并在体外对I类HDAC进行测试。为了验证其降解作用，均以HDAC2作为代表进行筛选。优选候选物在不同浓度下对各类HDAC亚型进行了评估。最终发现一种PROTAC（32a）（HI31.1）能以DC50值8.9 nM降解HDAC8，且具有良好的选择性。它还能以DC50值14.3 nM降解HDAC6。对白血病细胞（MV-4-11）进行的凋亡研究显示，在100 nM时发生超过50%的细胞凋亡。PROTAC 32a（HI31.1）对正常细胞株表现出良好的安全边际且具有良好的化学稳定性。

Abstract

Class I HDACs are considered promising targets for cancer due to their role in epigenetic modifications. The main challenges in developing a new, potent and non-toxic class I HDAC inhibitor are selectivity and appropriate pharmacokinetics. The PROTAC technique (Proteolysis Targeting Chimera) is a new method in drug development for the production of active substances that can degrade a protein of interest (POI) instead of inhibiting it. This technique will open the era to produce selective and potent drugs with a high margin of safety. Previously, we reported different inhibitors targeting class I HDACs functionalized with aminobenzamide or hydroxamate groups. In the current research work, we will employ PROTAC technique to develop class I HDAC degraders based on our previously reported inhibitors. We synthesized two series of aminobenzamide-based PROTACs and hydroxamate-based PROTACs and tested them in vitro against class I HDACs. To ensure their degradation, all of them were screened against HDAC2 as representative example of class I. The best candidates were evaluated at different concentrations at various HDAC subtypes. This resulted in the PROTAC (32a) (HI31.1) that degrades HDAC8 with a DC50 of 8.9 nM with a proper margin of selectivity against other isozymes. Moreover, PROTAC 32a is able to degrade HDAC6 with DC50 = 14.3 nM. Apoptotic study on leukemic cells (MV-4-11) displayed more than 50 % apoptosis took place at 100 nM. PROTAC 32a (HI31.1) showed a good margin of safety against normal cell line and proper chemical stability.