Prostasin regulates iNOS and cyclin D1 expression by modulating protease-activated receptor-2 signaling in prostate epithelial cells.
BACKGROUND
Prostasin is down-regulated during inflammation and in invasive cancers, and plays a role in regulation of inflammatory gene expression and invasion.


METHODS
We used the human benign prostatic hyperplasia cell line BPH-1 to investigate gene expression changes associated with siRNA-mediated loss of prostasin expression. Quantitative PCR and/or western blotting were used to evaluate the expression changes of iNOS, ICAM-1, cyclin D1, IL-6, and IL-8. Gene expression changes were also evaluated in the presence of a PAR-2 antagonist. The PC-3 human prostate cancer cell line was used for evaluation of gene expression in response to prostasin re-expression.


RESULTS
Prostasin silencing in BPH-1 was associated with up-regulation of iNOS, ICAM-1, IL-6, and IL-8, and down-regulation of cyclin D1; as well as reduced proliferation and invasion. The iNOS up-regulation and cyclin D1 down-regulation associated with prostasin silencing were inhibited by a PAR-2 antagonist. Re-expression of prostasin, a serine active-site mutant, and a GPI-anchor-free mutant, in the PC-3 cells resulted in PAR-2 and cyclin D1 transcription up-regulation. Transcription up-regulation of IL-6 and IL-8 was associated with re-expression of the serine active-site mutant prostasin in the PC-3 cells. Transcription up-regulation of IL-8, but to a lesser extent, was also observed in PC-3 cells expressing the wild-type prostasin. Expression of a serine protease active prostasin, GPI-anchored or anchor-free, prevented the IL-6 induction in response to PAR-2. The GPI-anchor-free prostasin also prevented the IL-8 induction.


CONCLUSIONS
Prostasin plays a negative regulatory role on PAR-2-mediated signaling in prostate epithelial cells.
Chen
Li-Mei
LM
Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, Orlando, Florida, USA.
Hatfield
Meghan L
ML
Fu
Ya-Yuan
YY
Chai
Karl X
KX
D015153:Blotting, Western; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D019938:Cyclin D1 / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011467:Prostate / Q000378:metabolism* / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000378:metabolism* / Q000473:pathology; D034741:RNA, Small Interfering / Q000494:pharmacology; D044464:Receptor, PAR-2 / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015854:Up-Regulation / Q000187:drug effects; D000099271:Prostasin
D019938:Cyclin D1; D018799:Intercellular Adhesion Molecule-1; D015850:Interleukin-6; D016209:Interleukin-8; D052247:Nitric Oxide Synthase Type II; D034741:RNA, Small Interfering; D044464:Receptor, PAR-2; D012697:Serine Endopeptidases; D000099271:Prostasin; C496319:NOS2 protein, human