Pathological Roles of Prostaglandin E2-specific E-type Prostanoid Receptors in Hormone-sensitive and Castration-resistant Prostate Cancer

Background/Aim: Prostaglandin (PG) E2 mediates malignant aggressiveness by binding to four specific E-type prostanoid receptors (EP1R - 4R). This study aimed to clarify the pathological significance of EPRs in hormone-sensitive prostate cancer (HSPC) and castration-resistant prostate cancer (CRPC). Materials and Methods: EP1R - 4R expression was examined in 102 HSPC and 27 CRPC specimens. The relationships between their expression and proliferation index (PI), apoptotic index (AI), and vascular endothelial growth factor (VEGF)-A expression were analyzed. Results: EP4R expression in CRPC was significantly higher compared to that in HSPC, even in advanced disease (T3/4, N1, and/or M1). EP4R expression was significantly correlated with PI, AI, and VEGF-A expression in CRPC. Such significant relationships were not detected between EP1R - 3R and CRPC. Conclusion: EP4R expression in CRPC was significantly higher than that in HSPC and was associated with cancer cell proliferation, apoptosis, and pro-angiogenetic potential.