PROJECT SUMMARY Prostate cancer (PCa) is the second leading cause of cancer death in the United States among men and it is more common in African American males. Despite initial good responses to androgen deprivation or anti- androgen drugs, tumors invariably recur and develop into lethal castration resistant prostate cancer (CRPC). Currently, the available therapeutic options for CRPC, including the gold standard chemotherapy docetaxel, have only met with limited success. The 52 kDa FK506 binding protein (FKBP52) is a promising strategy for novel targeted therapeutic development. MJC13 and GMC1, two first-in-class drugs that specifically inhibit FKBP52- mediated potentiation of AR signaling, have been discovered by Dr. Cox at University of Texas at El Paso and further developed by Dr. Xie at Texas Southern University. The exciting anti-tumor efficacy observed in CRPC xenograft animal models encourage us to further develop novel targeted nano-drug delivery systems (NDDS) that specifically deliver MJC13 and GMC1 to the tumor site then steadily release the drug to facilitate synergistic effect with docetaxel to treat CRPC. Our aims are to develop folic acid (FA)-conjugated NDDS of MJC13 and GMC1 for specific tumor targeting, high efficacy and low off-target adverse reactions; to perform comprehensive in vivo pharmacokinetic and pharmacodynamic evaluations on the optimal NDDS of MJC13 and GMC1; to investigate combination therapy of MJC13 and GMC1 and docetaxel in comparison to the marketed anti-AR drug enzalutamide. We will use various techniques, rats, tumor xenograft mouse models and genetically engineered mouse models to conduct those experiments in collaboration with experts at TSU and other institutions. This project will seek support and evaluation from the CBMHR Administrative Core, will heavily utilize the Research Infrastructure Core to perform studies, and will disseminate the research findings from this project with various TSU communities via support from our Community Engagement Core (CEC). It will further enhance RCMI institutions? prestige in the areas of biomedical and minority health research. The successful execution of this research will result potential advanced treatment for CRPC patients.