Effects of calorie restriction (CR) and/or leucine (LEU) supplementation on energy responsive signals in Panc02 tumors. (A) Comparison of immunohistochemical analyses on tumor sections for phospho-mTOR (P <0.05 between groups with different letters), phospho-S6 (P <0.001 between control and CR; P <0.01 between control + LEU and CR; P <0.05 between CR and CR + LEU), cyclin D1 (P <0.05 between groups with different letters), phospho-ACC (P <0.05 between the two leucine-supplemented groups; P <0.001 between all other groups with different letters) (n = 5/group). Scale bars represent 200 μm. All data are presented as the mean ± SEM. Differences are considered significant if P <0.05. Abbreviations: CON, control diet; CR,calorie restriction diet; LEU, leucine-supplemented diet.