Fig. 4.

SCH772984 synergizes with VS-5584 in inducing cell death and proliferation inhibition in primary AML patient samples. (A) Primary AML patient sample AML#40 was treated with 2 μM VS-5584 (VS), 2 μM SCH772984 (SCH), or 2 μM VS + 2 μM SCH for 48 h. Whole cell lysates were subjected to Western blotting and probed with the indicated antibodies. Normalized densitometry measurement results are shown. Western blots were repeated once (due to limited sample) and one representative cropped blot is shown. (B, C) Primary AML patient samples (AML#40 and AML#42) were treated with VS, SCH, or in combination for 48 h. Mean percent Annexin V+ cells ± SEM are shown. CI values were calculated using CompuSyn software. *** indicates p < .001. (D) MTT assays were performed using primary AML patient samples treated with VS-5584 and SCH772984 for 72 h. The IC₅₀ values are means of duplicates from one experiment due to limited sample. Standard isobolograms are shown. The IC₅₀ values for each drug are plotted on the axes; the solid line represents the additive effect, whereas the points represent the concentrations of each drug resulting in 50% inhibition of proliferation. Points falling below the line indicate synergism, whereas those above the line indicate antagonism. (E) Normal PMNCs were treated with VS-5584 and SCH772984, alone or in combination, for 72 h. Viable cells were determined using MTT assays.