Ultrasound-mediated microbubbles cavitation enhanced chemotherapy of advanced prostate cancer by increasing the permeability of blood-prostate barrier.

Although chemotherapy is an important treatment for advanced prostate cancer, its efficacy is relatively limited. Ultrasound-induced cavitation plays an important role in drug delivery and gene transfection. However, whether cavitation can improve the efficacy of chemotherapy for prostate cancer remains unclear. In this study, we treated RM-1 mouse prostate carcinoma cells with a combination of ultrasound-mediated microbubble cavitation and paclitaxel. Our results showed that combination therapy led to a more pronounced inhibition of cell viability and increased cell apoptosis. The enhanced efficacy of chemotherapy was attributed to the increased cell permeability induced by cavitation. Importantly, compared with chemotherapy alone (nab-paclitaxel), chemotherapy combined with ultrasound-mediated microbubble cavitation significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice in an orthotopic mouse model of RM-1 prostate carcinoma, indicating the synergistic effects of combined therapy on tumor reduction. Furthermore, we analyzed tumor-infiltrating lymphocytes and found that during chemotherapy, the proportions of CTLA4+ cells and PD-1+/CTLA4+ cells in CD8+ T cells slightly increased after cavitation treatment.