Figure 2

Effects of AFMC and/or TRAIL on the caspase activities of A549 cells. Figure 2A: Enzymatic activities of caspase -3, -8 and -9 were determined by incubation of 20 μg of total protein with 200 μmol/L chromogenic substrate (Ac-DEVD-pNA, Ac-IETD-pNA or Ac-LEHD-pNA) in 100 μL of assay buffer for 2 h at 37°C. The release of the chromophore p-nitroanilide (pNA) was monitored spectrophotometrically at 405 nm. Data are shown as mean ± S.D. (n = 3). a P < 0.05 vs. 0.2% DMSO; b P < 0.05 vs. 30 ng/mL TRAIL or 1.0 μmol/L AFMC alone. Figure 2B: A549 cells were pretreated with 1.0 μmol/L AFMC for 30 min and then treated with 30 ng/mL TRAIL for 24 h in the presence or absence of 10.0 μmol/L caspase inhibitors. Enzymatic activities of caspase -3, -8 and -9 were determined as described above. Data are shown as mean ± S.D. (n = 3). a P < 0.05 vs. 0.2% DMSO; b P < 0.05 vs. 30 ng/mL TRAIL or 1.0 μmol/L AFMC alone. Figure 2C: A549 cells were treated as described above. The frequency of cells in the sub-G1 phase was measured using flow cytometry. Data are shown as mean ± S.D. (n = 3). a P < 0.05 vs. 0.2% DMSO; b P < 0.05 vs. pretreatment with caspase inhibitors.