Evaluation of Senescence. MDA-MB-231 cells were cultured for 48 h with 25 μM Gli or with vehicle. Senescence was assessed by the activity of SA-β-GAL. Panel A: representative photographs where positive SA-β-GAL cells are indicated by arrows. Gli produces an increment in cell senescence. Panel B: Percentage of cells SA-β-GAL positive were calculated by counting of at least 1000 cells (630X). Bars represent the mean ± SEM of three independent experiments. *p < 0.001 vs. control, t test.