Aphidicolin decreases ex vivo resistance to cytosine arabinoside in childhood acute leukaemia

In order to assess the effect of the DNA polymerase inhibitor aphidicolin on resistance to cytosine arabinoside, blast cells from 15 children with ALL and 9 with AML were exposed to a range of concentrations of ara-C ± aphidicolin. Cell survival was measured using the MTT assay. Aphidicolin significantly increased sensitivity to ara-C in blast cells from both ALL (p=0.001) and AML (p 0.05). These remarkable results suggest that aphidicolin should be considered for future clinical trials as a modulator of ara-C resistance, particularly in AML.