Antiproliferative and Antiangiogenic Activities of Smenospongine, a Marine Sponge Sesquiterpene Aminoquinone

We previously reported that smenospongine, a sesquiterpene aminoquinone isolated from the marine sponge Dactylospongia elegans, showed antiproliferative or cytotoxic activities on leukemia cells. In this study, we investigated the effect of smenospongine on solid tumors. Since angiogenesis is well known to be closely involved in growth and metastasis of solid tumors, the antiangiogenic effect of smenospongine was determined. We found that smenospongine inhibited proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVEC). Moreover, the inhibitory activity of smenospongine on growth of solid tumor cells was investigated. Smenospongine inhibited the growth of 39 human solid cancer cells in vitro, with a mean Log GI(50) value of −5.55. In conclusion, smenospongine exhibits antitumor activity on solid tumors via two mechanisms, an antiangiogenic effect on endothelial cells and direct inhibition of growth of tumor cells.