Effects of ellipticine, ET-1, and ET-2 (8–5000 μM) on DNA decatenation catalyzed by human topoisomerase IIα. Assays containing intact kDNA in the absence of topoisomerase IIα (DNA), or kDNA treated with topoisomerase IIα in the absence of ellipticine-based compounds (TIIα) or in the presence of compound diluent (TIIα + DMSO) are shown as controls. The positions of intact kDNA at the origin (kDNA), decatenated nicked kDNA minicircles, and decatenated supercoiled kDNA minicircles are indicated. Gels are representative of three independent experiments.