Potentiation of hydroxyurea cytotoxicity in human chronic myeloid leukemia cells by iron-chelating agent

Abstract The effect of hydroxyurea (HU) was studied in 15 cases of human chronic myeloid leukemia cells (CML) in combination with iron-chelating agent, 2,2-bipyridine (bipyridine). The extent of ( 3 H)thymidine incorporation in CML cells in vitro was taken as an index for the measurement of cytotoxicity. In the present study, we observed a potentiation in HU cytotoxicity by hydrophobic iron-chelator bipyridine ( p −4 M and 10 μg/ml, respectively. This inhibition was found to be partially reversible and a partial protective action by iron is also demonstrated. The various other metal chelators failed to sensitise CML cells to HU cytotoxicity. Implications with respect to the efficacy in cancer treatment is discussed.