XAF1 expression and regulatory effects of somatostatin on XAF1 in prostate cancer cells

Background: Somatostatin prevents cell proliferation by inducing apoptosis. Downregulation of the XAF1 transcript may occur during the development of prostate cancer. It is interesting to evaluate the potential regulatory effects of somatostatin on XAF1 expression during the development of prostate cancer cells. Methods: XAF1 mRNA and protein expression in human prostate epithelial cells RWPE-1, androgen dependent prostate cancer LNCaP, and androgen independent DU145 and PC3 cells were evaluated using RT-PCR and Western blot. The regulation of XAF1 mRNA and protein expression by somatostatin and its analogue Octreotide was evaluated. Results: Substantial levels of XAF1 mRNA and proteins were detected in RWPE-1 cells, whereas prostate cancer cells LNCaP, DU145 and PC3 exhibited lower XAF1 expression. Somatostatin and Octreotide up-regulated XAF1 mRNA and protein expression in all prostate cancer cell lines. Conclusions: XAF1 down-regulation may contribute to the prostate cancer development. The enhanced XAF1 expression by somatostatin indicates a promising strategy for prostate cancer therapy.