Figure 2.

Antiproliferative effects of dexrazoxane (DEX) and XK469 and their influence on antiproliferative efficiency of daunorubicin (DAU). HL-60 leukemic cells were incubated with increasing concentrations of dexrazoxane (A), or XK469 (B) for 72 h and combined with daunorubicin in its IC₅₀ concentration (15 nM). The multiples of the respective IC₅₀ values of individual drugs were used in combination experiments according to Chou-Talalay with 48 h incubations (C, D; CI—combination index). Toxicity was assessed by MTT assay. Statistical analyses: n = 4, mean ± SD, 1-way ANOVA, Holm-Sidak’s post hoc test, p ≤ .05, “c”—compared with control, “d”—compared with daunorubicin.