Methods for early detection and/or prevention of the development of ovarian cancer are urgently required to improve the prognosis and overall survival of ovarian patients. Dr. Ni is focusing on studying whether proteins called proteases, enzymes that degrade other proteins in a process called proteolysis, might be biomarkers to better understand the progression of ovarian cancer. Many proteases that perform highly substrate-specific proteolysis influence cancer survival and progression processes and are the focus of cancer research. Besides expression regulation, the activities of many proteases are modulated by the interactions with other proteases and protein inhibitors in the cells. Abnormal expression of proteases and inhibitors contributes to many human pathological processes including cancer initiation, progression, and metastasis. However, the relative expression and activity patterns of various proteases and inhibitors have not been defined in ovarian cancer. In this proposal, Dr. Ni will employ a customized human protease chip to perform a system-wide analysis of the expression patterns of proteases and protease inhibitors, and also evaluate the activity of the proteases in ovarian cancer. The results of this study will identify proteases and protease inhibitors that have differential expression and/or activity in ovarian tumors. This work will have a significant impact on identifying the important players of the proteolytic system in ovarian cancer and provide targets for early detection and preventing the initiation and metastasis of ovarian cancer.