Fig. 3

Buformin suppresses the stemness of breast cancer cells in vitro. a SKBR3 and BT474 cells were treated with buformin (0, 0.5, or 1 mM) for 48 h (N = 4). Then ALDH activity was measured using an ALDEFLUOR assay. The percentage of ALDH⁺ cells are presented in the graphs. b 78617 and BT474 cells were plated in ultra-low attachment plates and treated with buformin (0, 0.2, or 0.5 mM) for 7 days (N = 4). Primary tumorspheres were counted and imaged after 7 days. Then the cells were harvested and homogenized to form a single cell suspension that was replated in ultra-low attachment plates for another 7 days. Secondary tumorspheres were then counted and imaged. All values are graphed as the mean ± S.E. (*p < 0.05, **p < 0.01)