Prostaglandin F2α stimulation of cyclooxygenase-2 promoter activity by the FPB prostanoid receptor

We have recently shown that the FPB prostanoid receptor activates beta-catenin signaling through the activation of Rho in human embryo kidney (HEK)-293 cells stably expressing the FPB receptors. We now report that the FPB receptor can stimulate cyclooxygenase-2 promoter activity and may, therefore, regulate the expression of cyclooxygenase-2. This stimulation of cyclooxygenase-2 promoter activity is blocked by pretreatment with an inhibitor of Rho, but not with an inhibitor of protein kinase C (PKC). Potential up regulation of cyclooxygenase-2 expression by the FPB receptor would establish a positive feedback loop that would drive beta-catenin signaling and could be involved in cancer. (C) 2003 Elsevier Science B.V. All rights reserved.