ABSTRACT
This chapter provides an overview of the concept of targeting virus-induced cancer by cancer-killing viruses and have highlighted a few but important specific examples of using oncolytic viruses against oncovirus-associated tumors. It explores tumor-killing viruses as therapeutic tools against oncovirus-induced cancers. The chapter describes hypothetical and actual examples of rational exploitation of oncovirus-enforced tumor biology to enable/promote destructive replication of oncolytic viruses. It highlights some molecular loopholes left open by oncoviruses that can be exploited/usurped by oncolytic viruses. The chapter also highlights some unwitting targeting of oncovirus-induced tumors. It discusses potential defense mechanisms of oncoviruses. Indeed, in virus wars, the final battle is likely to be decided not by ground battles in single cells or even in the tumor bed but rather systemwide by the third player in the war—the host immune system. Oncolytic viruses are either attenuated viruses, such as natural vaccine strains or serially passaged viruses, or genetically engineered recombinant viruses.
