Figure 6

Inhibitory effects of metformin and tamoxifen on tumor growth in a nude mouse model. These experiments were performed as described in the “Methods”. When the tumors in nude mice reached 200 mm³, the mice were given metformin (2 mg/ml) in their drinking water, tamoxifen (60 mg/kg) through oral gavage or the two agents simultaneously. The tumor growth was assessed every 3 days until day 24 of treatment by measuring two perpendicular diameters and calculating the volume in mm³. (A) Photographs of typical tumors are shown. (B) Histograms represent the weight of tumors from the different groups. (C) Tumor growth curve. Statistical analysis was performed using one-way ANOVA and Student’s t-test day with the day 24 values only. *P < 0.05 compared with the Tam group. (D) Intratumoral target protein expression was assessed by Ki67, p-AMPK, p-mTOR and p-p70S6 immunolabeling on paraffin-embedded tumor sections. Representative images are shown (original magnification, 400x).