Abstract 1742: Molecular characterization of CRPC pathogenesis and development of a novel anti-PSMA-drug conjugated hybrid nanoparticle therapy with reduced cellular toxicity

Abstract

Abstract Background: Metastatic castration-resistant prostate cancer (mCRPC) is responsible for most of PCa deaths. Androgen deprivation therapy (ADT), taxanes and enzalutamide are the standard care for CRPC and mCRPC. Unfortunately, these approaches often fail to prevent tumor relapse due to at least in part, the inherently low oxygen levels within the prostate tumor environment. In addition to this, lower drug stability and fast drug clearance among ADT patients are the major therapeutic limitations in drug delivery and drug efficacy. Therefore, it is clinically warranted to develop an increased drug stability system to enhance the drug efficacy. Recent developments in drug delivery system including our earlier report, nanoparticle loaded drugs shows greater stability and better drug efficacy with sub-optimal drug concentrations in vitro. It is an essential to develop an ideal CRPC preclinical model system to test the anti-PSMA-drug conjugated hybrid nanoparticle efficacy with high drug stability with limited cellular toxicity. Materials and Methods: CRPC lines were developed from PSMA proficient LNCaP, LAPC4, C4-2, 22Rv1, and PSMA deficient PC3-ML cells with intermittent hypoxia. CRPC cells were analyzed for proliferation, RB status, AR signaling, migration invasion and drug resistance in both in vitro and in vivo. Further, CRPC bone metastases clinical samples from Thomas Jefferson University Hospital were compared with preclinical CRPC model. Efficient anti-PSMA-drug conjugated hybrid nanoparticle therapy was established. Results: Hypoxia resistance models show CRPC, RB loss, hormone therapy resistance in vitro and in vivo. Anti-PSMA-drug conjugated hybrid nanoparticle shows enhanced drug stability and drug efficacy in vitro and in vivo. Interestingly we observed fibrosis, immune impairment and inactive RB in bone metastatic CRPC samples correlated with our preclinical studies. Further, our clinical bone metastases samples present osteoblastic, osteolytic and osteoblastic & osteolytic nature. Anti-PSMA conjugated-drug loaded hybrid nanoparticles localized to PSMA specific cells in vitro & in vivo, causing cell cycle arrest. Drug loaded anti-PSMA conjugated hybrid nanoparticles did not cause major toxicities in mice. Conclusion: Hypoxia resistant mCRPC models are ideal and are comparable with CRPC induced bone metastases in patient’s samples. Drug-loaded anti-PSMA conjugated hybrid nanoparticles targets PSMA specific prostate cancer cells and show enhanced drug stability and drug efficacy in CRPC preclinical model. Citation Format: Thangavel Chellappagounder. Molecular characterization of CRPC pathogenesis and development of a novel anti-PSMA-drug conjugated hybrid nanoparticle therapy with reduced cellular toxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1742.