Prostate cancer-derived small extracellular vesicles promote osteoclastogenesis and cancer-induced osteolysis via miR-152-3p delivery

Extracellular vesicles (EVs) play critical roles in regulating bone metastatic microenvironment through mediating intercellular communications. Here, we report a direct regulatory mode between tumor cells and osteoclasts in osteolytic metastasis of prostate cancer via vesicular miRNAs transfer. Combined analysis of miRNAs profiles both in tumor-derived small EVs (sEVs) and osteoclasts identified miR-152-3p as a potential osteolytic molecules. Further in vitro experiments showed that sEVs were enriched in miR-152-3p, which targets osteoclastogenic regulator MAFB. Blocking miR-152-3p in sEVs upregulated the expression of MAFB and impaired osteoclastogenesis in recipient osteoclasts. In vivo xenograft mouse model found that blocking of miR-152-3p in sEVs significantly rescued the loss of trabecular architecture, while systemic inhibition of miR-152-3p using antagomiR-152-3p reduced the osteolytic lesions of cortical bone while remaining the basic trabecular architecture. Together, our findings suggest that miR-152-3p carried by prostate cancer-derived sEVs deliver osteolytic signals from tumor cells to osteoclasts, facilitating osteolytic progression in bone metastasis. Overall design: small RNA sequencing of small extracellular vesicles secreted by three human prostate cancer cell lines.