Apigenin enhances Apo2L/TRAIL-induced apoptosis via upregulation of DR5.

<p>A, DU145 cells were treated with various concentrations of each flavonoid for 24 hr, followed by treatment with or without 50 ng/ml Apo2L/TRAIL. After 24 hr, the sub-G1 population of the cells was measured using flow cytometry. B, DU145 cells were treated with the indicated concentrations of each flavonoid for 24 hr and harvested. The lysates were analyzed using Western blotting with an anti-DR5 antibody. β-actin was used as a loading control. C, DR5 mRNA was quantified by real-time RT-PCR and normalized by GAPDH. Columns, mean; bars, SD (n = 3). **<i>P</i><0.01 relative to control.