Figure 5

Tenovin-6 sensitizes ALL cells to conventional chemotherapeutic agents. A, Synergistic effect of the combination of Tenovin-6 and etoposide or cytarabine in ALL cells was assessed by MTS assay after incubation of ALL cells with a serial diluted mixture (at a fixed ratio) of the 2 drugs for 72 hours. CI is plotted against the fraction affected. A reference line is drawn at CI = 1. CI values of <1 indicated synergism between the 2 drugs. B, REH and NALM-6 cells were treated with the indicated concentrations of Tenovin-6 and etoposide or cytarabine for 48 hours. Apoptosis was determined by flow cytometry. The results shown are representative of 3 independent experiments. C, Apoptosis-inducing capacity of Tenovin-6 plus etoposide or cytarabine was examined by Western blotting for cleaved PARP in ALL cells treated with drug combinations for 48 hours.