Cancer-germline antigen vaccines and epigenetic enhancers: future strategies for cancer treatment

Importance of the field: Immunotherapy holds great potential for disseminated cancer, and cancer-germline (CG) antigens are among the most promising tumor targets. They are widely expressed in different cancer types and are essentially tumor-specific, since their expression in normal tissues is largely restricted to immune-privileged sites. Although the therapeutic potential of these antigens may be compromised by their highly heterogeneous expression in many tumors and low frequency in some cancers, recent developments suggest that tumor-cell-selective enhancement of CG antigen gene expression can be achieved using epigenetic modifiers. Areas covered in this review: We provide an overview of the potential of CG antigens as targets for cancer immunotherapy, including advantages and disadvantages. We also discuss the current state of development of CG antigen vaccines, and the potential synergistic effect of combining CG antigen immunotherapeutic strategies with epigenetic modifiers. What the reader will gain: The reader will gain an overview of the past, present and future role of CG antigens in cancer immunotherapy. Take home message: Chemoimmunotherapy using epigenetic drugs and CG antigen vaccines may be a useful approach for treating cancer.