According to Canadian Cancer Society, one in eight men will be diagnosed with prostate cancer (PCa) in his lifetime. Most of the PCa initially respond to the treatment but eventually, some of the tumors become resistant and develop into an incurable disease. Mechanisms promoting the treatment-acquired resistance are still elusive. Our study exploring the alterations of global protein abundance unveiled an elevation of the Asparagine Endopeptidase (AEP) in the treated PCa cells, and repression of the elevation delayed cancer cell growth. AEP is a protease enzyme functioning in the cellular organelle lysosome to cleave and degrade specific substrate proteins. The role of AEP in the treatment resistance in PCa has not been investigated, we therefore propose to explore the mechanisms of AEP elevation upon the treatment and the role of AEP in cell division, cell death and cell spread under treatment stress. We also plan to develop small-molecule inhibitors targeting AEP to evaluate the co-targeting efficacy in combination with the conventional treatment approach. Our work may identify a novel mechanism promoting the treatment-acquired resistance and highlight AEP as a potential therapeutic target in PCa.