Figure 4

Combination of ATO with 5-FU in HepG2 and LX2 cell lines. HepG2 cells (A) were treated with increasing concentrations of 5-FU in the absence or presence of ATO (5 μM) for 24 hrs (left panel). The bar graph (right panel) demonstrates relative proliferation values for HepG2 cells when treated with 5 mg/ml 5-FU alone, 5 μM ATO alone and the combination of 5 mg/ml 5-FU and 5 μM ATO (p value < 0.0001). (B) LX2 cells were treated with increasing concentrations of 5-FU in the absence or presence of ATO (10 μM) for 24 hrs (left panel). The bar graph (right panel) demonstrates relative proliferation values for LX2 cells when treated with 5 mg/ml 5-FU alone, 5 μM, 10 μM ATO alone and the combination of 5 mg/ml 5-FU + 5 μM or 10 μM ATO. For each concentration, percent inhibition values were calculated and data normalized to vehicle control and represented as n = 3 replicates+/− SEM. (C) Dose effect curve for ATO and 5-FU combination in HepG2 cells was generated using Calcusyn software. (D) HepG2 treated cell lysates (vehicle, 20 μM, 50 μM or 75 μM ATO, 5 mg/ml 5-FU or 5 μM ATO + 5 mg/ml 5-FU) and LX2 treated cell lysates (vehicle, 10 μM, 20 μM or 50 μM ATO, 5 mg/ml 5-FU or 10 μM ATO + 5 mg/ml 5-FU) assessed for procaspase-9 and XIAP expression by western blot analysis. GAPDH was utilized as a loading control.