Endometrial cancer is one of the most common gynecologic malignancies and many factors influence in its growth and development. As in many other types of cancer, prostaglandin E-2 (PGE(2)) is thought to be an accelerator of cell proliferation and endometrial cancer progression. In this study, we examined the effect of FuEP2/Ex2, a soluble decoy receptor for PGE2 on growth of endometrial cancer cells. A stable transfectant expressing FuEP2/Ex2 was established from human endometrial cancer Ishikawa cells (Ish-FuEP2/Ex2). Ish-FuEP2/Ex2 cells expressed FuEP2/Ex2 mRNA and protein. Expression levels of E-prostanoid receptor 1 (EP1), EP2, EP3, EP4, and F-prostanoid receptor (FP) were almost the same in Ish-FuEP2/Ex2 and vector control cells. Growth rates of Ish-FuEP2/Ex2 under normal culture conditions were also similar to vector control cells, although PGE(2)-induced growth stimulation was completely inhibited in Ish-FuEP2/Ex2 or by Ish-FuEP2/Ex2 culture medium. Moreover, phosphorylation of extracellular signal-regulated kinase (ERK) and induction of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), cyclin D1, and c-fos mRNA by PGE2 were not observed in Ish-FuEP2/Ex2 and Ish-FuEP2/Ex2 culture medium-treated vector control cells, although they were found when treated with prostaglandin F-2 alpha. An orthotopic xenograft model in athymic nude mice revealed that Ish-FuEP2/Ex2-injected mice had significantly decreased mean tumor area. The proportion of Ki-67-positive cells in the tumor lesion was also significantly lower in Ish-FuEP2/Ex2-injected mice. These findings suggest that an EP-targeting strategy using FuEP2/Ex2 may be of use in the treatment of endometrial cancer. (C) 2011 Elsevier Ireland Ltd. All rights reserved.