Figure 4. Effect of metformin on the CSCs or CS-like cells.

Cells were incubated with different concentrations of metformin for 48 h, dispersed to single cells, washed, and the fraction of CSCs or CS-like cells were analyzed. (A) FACS for CD44^high/CD24^low cells of MCF-7 cells treated with 0.5–5.0 mM metformin for 48 h. (B) % of CD44^high/CD24^low MCF-7 cells in the surviving cells after treating with different concentrations of metformin for 48 h. Means of 7 experiments ± 1 S.E are shown. The declines in % of CD44^high/CD24^low cells by 0.5–10 mM metformin were statistically significant (P < 0.05). (C) FACS for ALDH1-positive FSaII cells treated with metformin for 48 h. (D) % of ALDH1-positive cells of FSaII cells treated with different concentrations of metformin for 48 h. Means of 5–7 experiments ± 1 S.E are shown. The declines in % of ALDH1-positive cells by 0.1–1.0 mM metformin were statistically significant (P < 0.05). (E) Changes in % of SP cells in FSaII cells treated with different concentrations of metformin for 48 h.