Fig. 6. Effect of ursolic acid (UA) on mammosphere-forming ability and migration of MCF-7 cell-derived breast cancer stem (BCS)-like cells. (A) Cells were treated with UA (0, 5, 10, and 20 μM) in ultra-low 6-well plates for 48 hours, the UA-containing medium was removed, and cells were incubated for 28 days to induce mammosphere formation. Phase-contrast microscopy was used to monitor mammosphere growth over 28 days. Cell morphology was visualized using inverted microscopy (×100). Scale bar, 200 μm. (B) Quantitative analysis of mammosphere size. (C) Effect of UA on the migration of MCF-7 cell-derived BCS-like cells. Cells were grown to confluence in 6-well plates coated with 0.02% gelatin, scratch-wounded, and treated with various concentrations of UA for 48 h. (D) The percentage distribution of the average wound area, as measured using ImageJ. Results are presented as mean±SD. *P<0.05 and **P<0.01 vs. control cells.