Discovery of Tertiary Benzenesulfonanilide Chemotypes as HDAC Inhibitors via Multistrategy In Silico and Biological Evaluation for Colon Cancer Therapy

Histone deacetylase (HDAC) inhibitors exert anticancer effects through epigenetic regulation. Developing HDAC inhibitors with different chemical types represents a promising anticancer treatment strategy. Herein, we established an enhanced comprehensive computational pipeline to identify tertiary benzenesulfonanilide-based HDAC inhibitor lead compounds and elucidate activity differences among derivatives based on electronic properties. Highly active HIT211504993 is a potent inhibitor selective for HDAC6 (IC₅₀ = 0.07 μM) over HDAC2 and HDAC4. HIT211504993 (20 μM) suppresses colon cancer cell proliferation and induces apoptosis in vitro and significantly inhibits tumor growth (50 mg/kg, 77%) in an HCT-8 xenograft model, comparable to SAHA (50 mg/kg, 81%). Mechanistically, HIT211504993 inhibits Myc-driven tumorigenesis by promoting nucleocytoplasmic acetylation and modulating p53, cell-cycle, and Wnt/β-catenin signaling. The investigation of antitumor activity and its mechanism of action provides a theoretical basis for the development of the next-generation benzenesulfonanilide HDAC inhibitors.