Figure 4.

Metformin and doxorubicin act in combination to reduce tumor mass and prolong remission in nude mice. A, Tumor volume (mean values and 95% confidence intervals) of mice injected with transformed MCF10A-ER-Src cells (time 0 indicates the time of injection) that were untreated, or treated by intraperitoneal injections every 5 days (3 cycles; arrows indicate the day or injections) with 4 mg/kg doxorubicin (Dox), 100 μg/ml metformin (Met), or both. B, Number of cancer stem cells (CD44^high/CD24^low) in cells obtained from tumors treated with Dox or the combination of Dox + Met after 3 cycles of treatment (day 25).