Figure 5. Effects of dietary Vitamin D₃ on PTEN expression during tumor progression.

(a) Top panels show representative images taken at a 20x magnification, scale bar  = 20 µm of normal skin, benign papillomas, MiSCC and SCC from mice fed diets of increasing concentrations of Vitamin D₃ stained for PTEN. (b) Quantitation of PTEN levels from three animals per treatment condition is plotted. Y-axis represents the mean fluorescent intensity, normalized to background, in arbitrary units. Error bars represent s.e.m. * = p≤0.05 compared to normal skin from the same diet; # = p≤0.05 compared to tissue of same tumor grade from mice fed 3 IU Vitamin D₃.