Docetaxel (Dtxl) is currently the most common therapeutic option for prostate cancer (PC). However, adverse side effects and problems associated with chemo-resistance limit its therapeutic outcome in clinical settings. A targeted nanoparticle system to improve its delivery to and activity at the tumor site could be an attractive strategy for PC therapy. Therefore, the objective of this study was to develop and determine the anti-cancer efficacy of a novel docetaxel loaded, prostate specific membrane antigen (PSMA) targeted superparamagnetic iron oxide nanoparticle (SPION) (J591-SPION-Dtxl) formulation for PC therapy. Our results showed the SPION-Dtxl formulation exhibits an optimal particle size and zeta potential, which can efficiently be internalized in PC cells. SPION-Dtxl exhibited potent anti-cancer efficacy via induction of the expression of apoptosis associated proteins, downregulation of anti-apoptotic proteins, and inhibition of chemo-resistance associated protein in PC cell lines. J591-SPION-Dtxl exhibited a profound uptake in C4-2 (PSMA+) cells compared to PC-3 (PSMA−) cells. A similar targeting potential was observed in ex-vivo studies in C4-2 tumors but not in PC-3 tumors, suggesting its tumor specific targeting. Overall this study suggests that a PSMA antibody functionalized SPION-Dtxl formulation can be highly useful for targeted PC therapy.

The therapeutic application of microRNA(s) in the field of cancer has generated significant attention in research. Previous studies have shown that miR-205 negatively regulates prostate cancer cell proliferation, metastasis, and drug resistance. However, the delivery of miR-205 is an unmet clinical need. Thus, the development of a viable nanoparticle platform to deliver miR-205 is highly sought. A novel magnetic nanoparticle (MNP)-based nanoplatform composed of an iron oxide core with poly(ethyleneimine)-poly(ethylene glycol) layer(s) was developed. An optimized nanoplatform composition was confirmed by examining the binding profiles of MNPs with miR-205 using agarose gel and fluorescence methods. The novel formulation was applied to prostate cancer cells for evaluating cellular uptake, miR-205 delivery, and anticancer, antimetastasis, and chemosensitization potentials against docetaxel treatment. The improved uptake and efficacy of formulations were studied with confocal imaging, flow cytometry, proliferation, clonogenicity, Western blot, q-RT-PCR, and chemosensitization assays. Our findings demonstrated that the miR-205 nanoplatform induces significant apoptosis and enhancing chemotherapeutic effects in prostate cancer cells. Overall, these study results provide a strong proof-of-concept for a novel nonviral-based nanoparticle protocol for effective microRNA delivery to prostate cancer cells.

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