UA induces apoptosis in GBC cells. GBC-SD and SGC-996 cells were treated with different concentrations of UA for 48 h. (A) Flow cytometric analysis of UA-induced apoptosis in GBC cells using annexin V-FITC/PI staining. Cells in the lower right quadrant represent early apoptotic cells, and those in the upper right quadrant represent late apoptotic cells. (B) The percentage of apoptotic cells is presented as the mean ± SD. The data are representative of 3 similar experiments. Significant differences from the control are indicated by *p < 0.05, **p < 0.01 and ***p < 0.001.