| Immunotherapy is considered as an effective method for cancer treatment owing to the induction of specific and long-lasting
anti-cancer effects. Immunotherapeutic strategies have shown significant success in human malignancies, particularly in
prostate cancer (PCa), a major global health issue regarding its high metastatic rates. In fact, the first cancer vaccine approved
by FDA was Provenge, which has been successfully used for treatment of PCa. Despite the remarkable success of cancer
immunotherapy in PCa, many of the developed immunotherapy methods show poor therapeutic outcomes. Immunosuppression
in tumor microenvironment (TME) induced by non-functional T cells (
CD4+ and CD8+),
tolerogenic dendritic cells
(DCs), and regulatory T cells, has been reported to be the main obstacle to the effectiveness of anti-tumor immune responses
induced by an immunotherapy method. The present review particularly focuses on the latest findings of the immune checkpoints
(ICPs), including CTLA-4, PD-1, PD-L1, LAG-3, OX40, B7-H3, 4-1BB, VISTA, TIM-3, and ICOS; these checkpoints
are able to have immune modulatory effects on the TME of PCa. This paper further discusses different approaches in ICPs
targeting therapy and summarizes the latest advances in the clinical application of ICP-targeted therapy as monotherapy or
in combination with other cancer therapy modalities in PCa. |