BPH-1 induces aromatase expression in prostatic stromal cells through paracrine of PGE2

AIM: To characterize the effect of prostatic epithelial cell paracrine on aromatase expression in prostatic stromal cells.METHODS: Conditioned medium (CM) of prostatic epithelial cell lines (BPH-1, LNCap, DU-145 and PC3) were collected and used to treat prostatic stromal cells. Expression of aromatase was determined by real-time RT-PCR and Western blotting. Expression of cyclooxygenase-2 mRNA in prostatic epithelial cell lines and prostaglandin (PGE2) in CMs were examined by real-time RT-PCR and ELISA, respectively. The CM of BPH-1 cells cultured with NS-398, specific inhibitor of cyclooxygenase-2, were collected, and the effect of NS-398 and PGE2 on aromatase expression was analyzed.RESULTS: CM of human benign prostate hyperplasia epithelial cell line (BPH-1) stimulated expression of aromatase mRNA and protein in stromal cells. But CM of prostate cancer epithelial cell lines (LNCap, DU145, PC3) had no effect on aromatase expression. COX-2 mRNA level in BPH-1 was much higher than that of other cell lines and PGE2 concentration in BPH-1 CM was much higher than that of other CMs. PGE2 concentration of the CM from BPH-1 cultured with NS-398 significantly decreased. CM from BPH-1 cultured with NS-398 failed to stimulate aromatase expression, while PGE2 induced aromatase expression in prostatic stromal cells.CONCLUSION: BPH-1 could induce aromatase expression in prostatic stromal cells through paracrine of PGE2.