RAPGEF3 and prostate carcinoma: We demonstrate that silencing the expression of Epac1 nearly abolished 8-CPT-2Me-cAMP induced COX-2 expression in 1-LN prostate cancer cells (Figure 7), thereby identifying a mechanism by which PGE2-induced upregulation of COX-2 expression is mediated by Epac1 in an cyclic manner.