Bacterial and viral therapies of cancer background, mechanism and perspective

Bacterial and viral therapies of cancer are highly promising, yet their mechanisms are incompletely understood, hindering their improvement and application. In this paper, We (1) review briefly the genesis and progress of bacterial and viral therapies of cancer, (2) compare and evaluate the proposed mechanisms of bacterial and viral therapies of cancer and present the unifying mechanism that bacteria/viruses stimulate cancer cells to produce antibacterial/antiviral proteins, which also serve as the responsive cancer antigens triggering host anticancer immune response, and (3) provide a perspective on the exploitation of non-human and non-animal bacteria and viruses, particularly protist-infecting bacteria and viruses and bacterial virus (bacteriophage/phage), for cancer treatment and prevention.