Cytotoxic and DNA-inhibitory effects of iron chelators on human leukaemic cell lines

Cytotoxic and DNA synthesis inhibitory effects of several iron chelators with different physicochemical properties have been tested in four myeloid leukaemic cell lines (U937, K562, ML2 and HL60). The small lipophilic chelators 8-hydroxyquinoline, tropolone and omadine at 2 X 10(-5) M, caused substantial inhibition of labelled leucine and thymidine uptake into cells and also cell death following 4-h incubation. These effects were approximately 10-fold increased when the drugs were pre-incubated with equimolar amounts of iron. Iron alone and hydrophilic chelators e.g. desferrioxamine had insignificant cytotoxic and DNA synthesis inhibitory effects under the same conditions.