NCIt definition : A highly cytotoxic macrocyclic lactone polyether with antitumor activity. Spongistatin,
originally isolated from marine Spongia species, binds to the vinca domain of tubulin,
thereby interferes with microtubule assembly and results in inhibition of mitosis.
This agent does not affect the binding of colchicine to tubulin, but it was a potent
inhibitor of the binding of vinblastine and GTP to tubulin.;