Antitumoral activity of ATP-competitive inhibitors of mTOR combined with U0126. A: Nude mice bearing LS174T (left panel) or SW480 (right panel) tumor xenografts were treated with vehicle (C), rapamycin (R, 1.5 mg/kg/day), PP242 (P, 60 mg/kg/day), NVP-BEZ235 (N, 30 mg/kg/day), in combination or not with U0126 (40 μmol/kg/d, i.p.). After 20 days of treatment, tumor volumes were evaluated using caliper measurements and calculated with the formula V = π/6 × a2 × b where a is the short axis and b the long axis of the tumor. Columns, mean tumor volume (five tumor xenografts in each group); bars, SD. *, P < 0.05, compared to control, or otherwise as specified by brackets. B: Tumor lysates were generated from the harvested xenografts and analyzed for pMAPK, MAPK, cleaved caspase-3 and actin expression. C: Frozen sections of the harvested tumor xenografts were stained with an anti-Ki-67 antibody. The effect of the different treatments on Ki-67 positivity was quantified and expressed as % of cells positive for Ki-67/total number of cells (300 cells counted per tumor; five tumors in each group). Columns, mean % of cells positive for Ki-67 staining; bars, SD. *, P < 0.05 compared to control, or otherwise as specified by brackets.
Blaser et al. BMC Cancer 2012 12:86 doi:10.1186/1471-2407-12-86