Figure 1

Combination effect of GO with DAC, VPA or AZA in CD33-positive leukemic cells. Cells were treated with 100 nM DAC (a, b, g), 1 mM VPA (c, d) or 2 μM AZA (e, f) for 48 h before GO (2.5 μg/ml) administration, cultured for an additional 24 h, and then apoptosis was measured. Apoptotic cells (%) increased in SKNO-1, SKK-1, SKM-1, U-937 and K052 cells when combined with DAC (a), in SKNO-1, SKK-1 and Kasumi-3 cells when combined with VPA (c) and in SKM-1 cells when combined with AZA (e). (b, d, f) Cell lines show relative apoptosis, namely apoptotic cells (%) in combination/apoptotic cells (%) in single GO administration, with any number >1 indicating a combination effect versus any number <1 meaning no combination effect. Combination of GO and DAC was superior in both the number of cell lines impacted and mean relative apoptosis. (g) Combination effect of GO with DAC was seen in four cells among 14 cells from patients with refractory AML. The degree of effect varied widely.