Figure 1.

Effect of GSPs on PGE₂ receptors and PGE₂ receptors agonist-mediated effect on melanoma cell migration. A. Treatment of A375 and Hs294t cells with GSPs (0, 10, 20 and 40 µg/mL) for 24 h decreases the expression levels of PGE₂ receptors (EP2 and EP4). Cell lysates were subjected to western blot analysis to determine the levels of EP2 and EP4. B. Treatment of GSPs inhibits EP2 agonist (Butaprost, 1.0 µM)-induced migration of A375 melanoma cells (left panel) and data of cell migration in each treatment group are summarized as a mean number of migratory cells ± SD/microscopic field, n = 3 (right panel). C. Treatment of GSPs inhibits EP4 agonist (Cay10580, 1.0 µM)-induced migration of A375 melanoma cells. Representative photomicrographs of cell migration are shown (left panels). The data on cell migration are summarized as a mean number of migratory cells ± SD/microscopic field, n = 3 (right panel). Significant inhibition versus non-GSPs-treated control group, *P<0.001; Significant increase versus non-EP2 agonist-treated or non-EP4 agonist-treated controls, †P<0.001. D. GSPs treatment decrease EP2- and EP4- agonist induced expression levels of nuclear and cytosolic β-catenin in A375 cells.