Chiral salicyl diamines: Potent anticancer molecules

A set of 12 enantiomeric diamine-based small molecules was synthesized and screened for anticancer activity against five human cancer cell lines : NCI-H460, A549, MCF-7, SK-BR-3, and T-47D. The salicyl diamino compounds (1-6) were found to induce inhibition of the growth of cancer cells at submicromolar concentrations. The lead compound, N,N′-bis-salicyl-(1R,2R)- diaminocyclohexane (1) displayed single-reagent anticancer activity with an IC₅₀ value equal to or less than 2.0 μM in H460 and A-549 cancer cells. SRB and colony formation assays indicated that compound 1 shows greater cytotoxic activity toward MCF-7 cells than MCF-10A cells. Real-time RT-PCR analysis demonstrated that compound 1, is an extremely efficient regulator of antiapoptotic genes, Bcl-xL, Bcl-2, and the cell cycle related gene, cyclin D1. This study provides a new insight into the development of novel small molecules in the treatment of human breast cancers.