A substance being studied in the treatment of cancer. It binds to a protein that cells need to divide and it may kill cancer cells. Dolastatin 10 comes from a marine organism. It is a type of mitotic inhibitor. OR A pentapeptide originally isolated from the marine mollusk Dolabella auricularia with potential antineoplastic activity. Binding to tubulin, dolastatin 10 inhibits microtubule assembly, resulting in the formation of tubulin aggregates and inhibition of mitosis. This agent also induces tumor cell apoptosis through a mechanism involving bcl-2, an oncoprotein that is overexpressed in some cancers.