Makaluvamines vary in ability to induce dose-dependent DNA cleavage via topoisomerase II interaction

The makaluvamines are marine natural products that were originally isolated because of their cytotoxicity in a cell-based mechanism screen. They have significant anti-cancer activity in animal models. There is, however, disagreement in the literature as to whether these compounds target topoisomerase II via a clinically relevant mechanism. This work shows that the makaluvamines can induce dose-dependent DNA cleavage via topoisomerase II. For most of the makaluvamines the levels of cleavage are significantly below those achieved by equimolar concentrations of etoposide. To some extent these results might explain the discrepancies present in the literature.