Stage-specific Embryogenic Antigen-4 Expression in Castration-resistant Prostate Cancer and its Correlation With the Androgen Receptor.

Background/aim Stage-specific embryonic antigen (SSEA)-4 plays important roles in the malignant aggressiveness of various cancers. The aim of this study was to investigate the pathological characteristics of SSEA-4 in castration-resistant prostate cancer (CRPC). Materials and methods SSEA-4 expression and its pathological roles were evaluated in five prostate cancer (PC) cell lines and 27 CRPC tissues. The relationship between SSEA-4 and the androgen receptor (AR) was also examined. Results SSEA-4 expression was detected in AR-negative cells (PC3, DU145, and AICaP1) but was not detected in AR-positive cells (LNCaP and AICaP2). SSEA-4 expression in human CRPC tissues was significantly higher than that in locally advanced or metastatic hormone sensitive PC (HSPC) tissues. A negative correlation was also detected between SSEA-4 and AR in CRPC tissues but not in HSPC tissues. Conclusion SSEA-4 was over-expressed in CRPC and the changes were mediated by complex mechanisms that related to the AR and hormonal therapy.