The taccalonolides, novel microtubule stabilizers, and γ-radiation have additive effects on cellular viability.

The taccalonolides are novel antimitotic microtubule stabilizers that have a unique mechanism of action independent of a direct interaction with tubulin. Cytotoxicity and clonogenic assays show that taccalonolide A and radiation act in an additive manner to cause cell death. The taxanes and epothilones have utility when combined with radiotherapy and these findings further suggest the additive effects of microtubule targeting agents with radiation on cellular proliferation are independent of direct tubulin binding and are instead a result of the downstream effects of these agents. These studies suggest that diverse antimitotic agents, including the taccalonolides, may have utility in chemoradiotherapy.