Friday, December 8, 2023

Discovery of YSR734: A Covalent HDAC Inhibitor with Cellular Activity in Acute Myeloid Leukemia and Duchenne Muscular Dystrophy

Yasir S. Raouf, Abootaleb Sedighi, Mulu Geletu, Geordon A. Frere, Rebecca G. Allan, Nabanita Nawar, Elvin D. de Araujo, and Patrick T. Gunning

Journal of Medicinal Chemistry 2023
DOI: 10.1021/acs.jmedchem.3c01236

Histone deacetylases (HDACs) have emerged as powerful epigenetic modifiers of histone/non-histone proteins via catalyzing the deacetylation of ε-N-acetyl lysines. The dysregulated activity of these Zn2+-dependent hydrolases has been broadly implicated in disease, notably cancer. Clinically, the recurring dose-limiting toxicities of first-generation HDACi sparked a paradigm shift toward safer isoform-specific molecules. With pervasive roles in aggressive diseases, there remains a need for novel approaches to target these enzymes. Herein, we report the discovery of YSR734, a first-in-class covalent HDACi, with a 2-aminobenzanilide Zn2+ chelate and a pentafluorobenzenesulfonamide electrophile. This class I selective proof of concept modified HDAC2Cys274 (catalytic domain), with nM potency against HDAC1–3, sub-μM activity in MV4–11 cells, and limited cytotoxicity in MRC-9 fibroblasts. In C2C12 myoblasts, YSR734 activated muscle-specific biomarkers myogenin/Cav3, causing potent differentiation into myotubes (applications in Duchenne Muscular Dystrophy). Current efforts are focused on improving in vivo ADME toward a preclinical covalent HDACi.


Discovery of a Tunable Heterocyclic Electrophile 4-Chloro-pyrazolopyridine That Defines a Unique Subset of Ligandable Cysteines

Hong-Rae Kim, David P. Byun, Kalyani Thakur, Jennifer Ritchie, Yixin Xie, Ronald Holewinski, Kiall F. Suazo, Mckayla Stevens, Hope Liechty, ...