HPSC were transiently transfected with siControl, siEP2 or siEP4. After 48 hours, cell migration and invasion were assessed by counting the number of stained cells that penetrated the migration membrane after 24h following PGE2 (100nM) stimulation. (A) membrane alone (right, stained cells; left migration numbers p<0.05 versus control) (B) matrigel coated membrane (right, stained cells; left migration numbers p<0.05 versus control) (C) RT-PCR shows the effects of PGE2 mediated stimulation of COL1A1, MMP-2 and 9 after the silencing of EP4 receptor. β-actin served as control. (D) Q-RT-PCR shows the effects of PGE2 mediated stimulation of COL1A1, MMP-2 and 9 and decrease after the silencing of EP4 receptor. β-actin served as control.