Effect of pterostilbene (PTE) and megestrol acetate (megestrol) on the expression of cell signaling molecules. (a) HEC-1A cells were treated with pterostilbene or megestrol acetate at various concentrations for 24 h. Whole cells were collected and determined for the change of STAT3, AKT and ERK pathways and ER expression by Western blot. (b) HEC-1A cells were treated with pterostilbene (75 μM), megestrol acetate (75 μM) or the combination for 24 h. Whole cell lysates were collected and measured for the change of cell signaling pathways by Western blot. Results are representative of 3 or more preparations. (c) Relative levels of p-JAK2, p-STAT3, p-AKT, p-ERK and ER were determined by measuring the density of each band and normalized to that of GAPDH. Densitometry data were relative changes in protein expression and were mean ± SD of more than 3 preparations. *P < 0.05; **P < 0.005, ***P < 0.005.