UC San Diego

Novel 5-pyridinyl-1,2,4-triazoles were designed as dual inhibitors of histone deacetylase 2 (HDAC2) and focal adhesion kinase (FAK). Compounds 5d, 6a, 7c, and 11c were determined as potential inhibitors of both HDAC2 (IC₅₀ = 0.09-1.40 μM) and FAK (IC₅₀ = 12.59-36.11 nM); 6a revealed the highest activity with IC₅₀ values of 0.09 μM and 12.59 nM for HDAC2 and FAK, respectively. Compound 6a was superior to reference drugs vorinostat and valproic acid in its ability to inhibit growth/proliferation of A-498 and Caki-1 renal cancer cells. Further investigation proved that 6a strongly arrests the cell cycle at the G2/M phase and triggers apoptosis in both A-498 and Caki-1 cells. Moreover, the enhanced Akt activity that is observed upon chronic application of HDAC inhibitors was effectively suppressed by the dual HDAC2/FAK inhibitor. Finally, the high potency and selectivity of 6a towards HDAC2 and FAK proteins were rationalized by molecular docking. Taken together, these findings highlight the potential of 6a as a promising dual-acting HDAC2/FAK inhibitor that could benefit from further optimization.