Effect of CU-3 on the apoptosis of HepG2, HeLa, and COS-7 cells. A: Expression of DGKα [80 kDa and 70 kDa (10)] in HepG2, HeLa, and COS-7 cells. HepG2, HeLa, and COS-7 cells were harvested, and the cell lysates (15 μg of protein) were analyzed by Western blotting using anti-DGKα antibody. B–D: After the addition of 5 μM of CU-3 or DMSO alone, HepG2 (B), HeLa (C), and COS-7 (D) cells were incubated for 24 h. The caspase-3/7 assay was conducted according to the manufacturer’s description. After a 1 h incubation at 25°C, each sample was measured in a microplate reader. The values are presented as the mean ± SD (n = 6). *** P < 0.005.