Jin-xia Ma and Bing-xue Yan
Icesnow Yanyan Bioscience LLC. Baltimore MD 21224, USA
PSP94 (Prostatic secretory protein 94) is one of most abundant protein in the semen of healthy men and also found in a variety of human tissues, especially in female reproductive tissues such as the breast and ovaries. Prostasin, is a trypsin-like serine peptidase expressed in epithelial cells, with the highest expression in the normal prostate gland and seminal fluid and lesser amount in various tissues. Studies show that PSP94 is decreased and tumor suppressor in prostate cancer. PSP94 was foundto be overexpressed in breast cancer. The expression of prostasin has been shown to mal-express in ovarian, prostate, breast and gastric cancers. The findings suggest these two genes are potential key players in oncogenesis. Our recent experimental investigations demonstrated that PSP94 plays important roles in ovarian cancer chemoresistance and ovarian oncology that is found overexpressed in ovarian cancer cell lines and cancer patients. Importantly, our signaling pathway analysis showed PSP94 is a close upstream signaling mediator of prostasin in ovarian cancer that regulates prostasin expression and action in ovarian cancer cells. Additionally, PSP94 and prostasin are both upstream regulators of Lin28/Let-7 loop in ovarian cancer cells, a well-known signaling in oncogenisis in general, and is believed to play a critical role in stem cell development. PSP94 and prostasin are also found to regulate CASP-PAK2-p34 signaling, that may be involved in apoptosis pathwaysin ovarian cancer cells. These findings expand the current network of tumorigenesis in ovarian cancer. We propose PSP94 and prostasin may have close connection in other cancer types, especially prostate and breast cancers in which both genes are malexpressed. The investigations of PSP94 and PSP94 to prostasin signaling in oncogenesis in general are undergoing