Enhanced antitumor effects by the coculture of allotumor RNA-pulsed dendritic cells with autologous cytokine-induced killer cells on hormone-refractory prostate cancer

In this study, we evaluated antitumor effects of allotumour RNA-transfected dendritic cells (DCs) cocultured with autologous cytokine-induced killer cells (CIKs) on hormone-refractory prostate cancer. The cocultured cells enhanced prostate cancer cytolysis from 26% (CIKs-induced cytolysis) to 80.8%. They also increased the productions of CD4⁺ Th1 (IFN-γ⁺IL-4^-, 55.52%) and CD8⁺ T (IFN-γ⁺, 69.59%) cells determined by intracellular cytokines IFN-γ /IL-4 staining and reduced the rate of CD4⁺ CD25⁺ cells from 18.72% (in CIKs) to 9.72%. The cocultured cells significantly inhibited tumor growth in SCID mouse and induced cancer cells necrosis and apoptosis. Our study indicates that tumor RNA-pulsed DCs cocultured with autologous CIKs significantly enhance antitumor immunity, which can be induced by increased CD4⁺ Th1 and CD8⁺ T cells and decreased CD4⁺CD25⁺ regulatory T (T_reg) cells. This provides a potential immunotherapy strategy for HRPC.