Fig. 2

Caspase inhibitors and DR5/Fc chimeric protein block apoptosis induced by the combination of isoliquiritigenin and TRAIL. Colon cancer HT29 cells were treated with 10 ng/ml TRAIL and/or 40 μM isoliquiritigenin with or without caspase inhibitors (a) or DR5/Fc chimeric protein (b) for 24 h. The Sub-G1 population was analyzed by flow cytometry. The values shown are means (n = 3); bars, ±S.D. C3, caspase-3 inhibitor; C8, caspase-8 inhibitor; C9, caspase-9 inhibitor; C10, caspase-10 inhibitor; VAD, pan-caspase inhibitor. *P < 0.01 when compared with the sample treated with isoliquiritigenin and TRAIL