3-Aroylindoles display antitumor activity in vitro and in vivo: Effects of N1-substituents on biological activity

A series of 3-aroylindole hydroxamic acids (10–17) were developed based on the concept of a structural combination of tubulin and histone deacetylase (HDAC) inhibitors. This was accomplished by introducing hydroxamic acid-containing moieties at the N1 position of the tubulin assembly inhibitor, compound 9 (SCB01A, BPR0L075, phase II trial). Most of synthetic compounds produced in this way displayed comparable HDAC inhibitory activity, and four (10, 12–14) of them also inhibit tubulin assembly. Notably, compound 12 possesses not only tubulin and HDAC inhibitory activity but also shows HDAC6 selectivity over other HDAC isoforms. In addition, it exhibits remarkable inhibitory activity against the growth cancer cells in vitro and in vivo (PC3 and RPMI-8226 cells). Notably, it suppresses the growth of multiple myeloma xenografts without leading to the death of teated animals like reference compound. In sum, this study provided potential compounds with safer profiles for cancer treatment.