361 Background: PCas are characterized by a primary androgen dependent stage, during which growth is promoted by androgen and suppressed by androgen deprivation or blockade, with even metastatic disease being promptly susceptible to hormonal manipulation; however, despite initial success, androgen deprivation therapy eventually fails because of the development of CRPC. Despite the approval of new clinical trials such as docetaxel, enzalutamide and sipuleucel-T, which is a cell therapy drug, the clinical efficacy is limited. Therefore, there is a desperate need for the limited effectiveness of treatment in an aging society and the development of successful treatments for patients who fail treatment. In this study, we investigated the anticancer effect of prostate cancer using anti-cancer immunity cell vaccine based on the next generation dendritic cell immunotherapy. Methods: FACS and ELISA were performed with stem-DC to analyze phenotype and cytokine expression. To quantify the effect on the tumor growth, we constructed a TRAMP-C1 model and observed for safety, efficacy and induction of antigen-specific immune responses. And we also analyzed proliferation and activation of allogeneic-T cells by therapeutic dendritic cells. Results: From the stem-DC, immune-stimulatory cytokine IL-12 and interferone-gamma was measured higher level than monocyte derived DC (Mo-DC). A DC marker CD11c+CD8a+ cell was higher expression in stem-DC than Mo-DC. After DC injection, tumor size was reduced in stem-DC compared to Mono-DC and vehicle group in TRAMP model. To confirm stem-DC/lysate induce more systemic anti-tumor immunity than Mo-DC/lysate, we checked effector T cells in splenic lymphocytes from prostate cancer bearing mice. The frequency of IFN-γ secreting CD8+ T cells in stem-DC treated group was significantly higher than that in Mo-DC treated group. It shows that the therapeutic responses were associated with induction of IFN-γ secreting CD8+ T cells. Conclusions: Stem-DC, which was developed from hematopoietic stem cells in an optimized manner, proved to be effective and stable as an excellent anti-cancer immunotherapeutic agent for prostate cancer.
Type-1 polarized dendritic cells loaded with apoptotic prostate cancer cells are potent inducers of CD8+
T cells against prostate cancer cells and defined prostate cancer-specific epitopes