Involvement of caspase-3 activity in H
or TNF α-induced apoptosis in OLFM4 knockdown SGC-7901 and MKN45 cells. (A-B) Increased caspase-3 activity in H2O2 or TNF α-treated OLFM4 knockdown cells. OLFM4 knockdown and HK-control cells were treated with 10 μM H2O2 (A) or 10 ng/ml TNF α (B) for 12 h. Caspase-3 activity was measured using colorimetric assay and expressed in fold changes. **P < 0.01 versus PBS mock group (n = 3). (C-D) Reversed cell apoptosis by caspase inhibitor in OLFM4 knockdown cells. Cells were treated with H2O2 or TNF α alone with indicated doses as above mentioned or pretreated with 20 μM Z-VAD-fmk 2 h before H2O2 or TNF α treatment. The percentage of apoptotic cells was determined by FCM. Data represent the means ± SD from three independent experiments. ** p < 0.01 vs. H2O2 (C) or TNF α (D)-treated OLFM4 knockdown cells group.