A novel exosome based therapeutic intervention against neuroendocrine prostate cancer.

Neuroendocrine prostate cancer (NEPC) is a highly lethal variant of castration-resistant prostate cancer (CRPC) with poor survival rates. Current treatment options for NEPC are limited to highly toxic platinum drugs highlighting the urgent need for new therapies. This study aimed to develop a novel therapeutic approach using engineered exosomes against NEPC. Exosomes were modified to target CEACAM5, an NEPC surface antigen, by attaching CEACAM5 antibodies to HEK293T exosomes. These exosomes were loaded with drugs inhibiting EZH2 and the androgen receptor (AR) as recent research shows a persistent role of AR in NEPC wherein it plays a concerted role with EZH2 in driving neuronal gene programs. In vitro experiments with NEPC cell lines demonstrated that CEACAM5-targeted exosomes were specifically taken up by NEPC cells, leading to reduced cellular viability and decreased expression of neuronal markers. Further in vivo tests using a NEPC patient-derived xenograft model (LuCaP145.1) showed significant tumor regression in mice treated with engineered exosomes compared to control mice receiving IgG-labeled exosomes. These results suggest that CEACAM5-engineered exosomes hold promise as a targeted therapy for NEPC. Importantly, our exosome engineering strategy is versatile and can be adapted to target various surface antigens in prostate cancer and other diseases.

miR-410 Is a Key Regulator of Epithelial-to-Mesenchymal Transition with Biphasic Role in Prostate Cancer.

The molecular basis of prostate cancer (PCa) progression from the primary disease to metastatic castration-resistant prostate cancer (CRPC) followed by therapy-induced neuroendocrine prostate cancer is not fully understood. In this study, we elucidate the role of miR-410, a little-studied microRNA located on chromosome 14q32.31 within the DLK1-DIO3 cluster, in PCa. miR-410 expression analyses in primary and metastatic PCa tissues and cell lines show that its levels are decreased in initial stages and increased in advanced PCa. Functional studies were performed in a series of PCa cell lines. In LNCaP cells, miR-410 overexpression led to decreases in cellular viability, proliferation, invasiveness, and migration. On the other hand, miR-410 overexpression in PC3 and C42B cells led to increased viability, proliferation, and invasiveness. Our data suggest that miR-410 represses epithelial-to-mesenchymal transition (EMT) in LNCaP cells by directly repressing SNAIL. However, it promotes EMT and upregulates PI3K/Akt signaling in PC3 and C42B cells. In vivo studies with PC3 xenografts support an oncogenic role of miR-410. These data suggest that miR-410 acts as a tumor suppressor in the initial stages of PCa and play an oncogenic role in advanced PCa. Our findings have important implications in understanding the molecular basis of PCa progression with potential translational implications.