Figure 7

p53-dependent apoptosis is induced by PSE in AGS gastric cancer cells. (A) AGS cells were exposed to 200 μg/ml PSE and 0.1% DMSO for 12 h and 24 h. The cell lysates were separated by SDS-PAGE gel electrophoresis, and Western blotting with specific antibodies was performed (anti-p53, anti-phospho-p53, anti-phospho-MDM2, and anti-α-actin). (B) The band intensities were normalized to α-actin. Bars, SD. *p < 0.05, **p < 0.01, ***p < 0.001, control versus PSE-treated cells. (C) AGS cells were exposed to 200 μg/ml PSE and 0.1% DMSO for 24 h either with or without p53 inhibitor (Pifithrin-α, 20 μM). The cell lysates were separated by SDS-PAGE gel electrophoresis, and Western blotting with specific antibodies was performed (anti-phospho-p53, anti-cleaved caspase-8, anti-cleaved caspase-3, anti-cleaved-PARP, and anti-Tubulin). The data shown are representative of three independent experiments that gave similar results.