CQ potentiates apoptosis of SGC cells induced by 5-FU. (A) The population of annexin V+ apoptotic cells were evaluated by FCM using annexin V-FITC/PI staining in SGC-996 cells and GBC-SD cells after CQ-pretreatment at 100 μM for 12 hours, followed by 5-FU at 5 μM for 48 hours. The percentage of annexin V+ apoptotic cells increased by pretreatment with CQ followed by 5-FU. Values were given as mean ± SD. (B) GBC cells were treated with CQ at 100 μM for 12 hours, washed with PBS, and/or treated by 5-FU at 5 μM for 48 hours respectively. GAPDH was used as an internal control. Cleavage of PARP induced by 5-FU and CQ in GBC cells was examined with Western Blotting analysis. The values of the band intensity below the figure represent the densitometric estimation of each band normalized by GAPDH. Experiments were repeated three times with reproducible results.