UA inhibits proliferation in GBC cells. (A) The chemical structure of UA. (B) GBC-SD and SGC-996 cells were treated with various concentrations of UA for 24, 48 or 72 h. Effects on cell proliferation were determined using a MTT assay. Each value represents the mean ± SD (n = 3). (C-D) UA inhibits colony formation in GBC cells. GBC-SD and SGC-996 cells were treated with different doses of UA (8, 16 or 32 μmol/L) and were allowed to form colonies in fresh medium for 14 days. The photomicrographic differences and number of colonies (mean ± SD, n = 3) in colony formation are shown. Significant differences from the control are indicated by *p < 0.05 and **p < 0.01.