In vivo anti-tumor effects of metformin in OSCC xenografts in nude mice. A total of 2 × 106 CAL27 cells/mouse were injected subcutaneously into the back next to the right hind limb, and permitted to grow until palpable. Metformin was administered orally for 15 days; control mice received drinking water only. (A) Graphs represent the average tumor volumes of CAL27 xenografts in mice from the control and metformin–treated groups. (B) Representative images of tumors from mice in the two groups. (C) Weight of tumors from the control and metformin-treated groups. (D) Cyclin D1 expression and apoptotic tumor cells in tumors from mice treated with or without metformin were assessed by IHC and TUNEL staining, respectively (original magnification is 200×). Five mice were included for each group, and results are representative of three experiments. (***p < 0.001).
Luo et al. BMC Cancer 2012 12:517 doi:10.1186/1471-2407-12-517