Oncolytic Viruses as Therapeutic Agents for Prostate Cancer

Viruses are commonly thought of as opportunistic organisms that hijack cellular machinery with the ultimate goal of replicating and causing destruction in the host. However, viruses are increasingly being explored as therapeutic agents for a variety of disorders and diseases, including cancers, due to their natural ability to spread to various cell types. Oncolytic viruses are replication-competent viruses that have the ability to selectively target cancerous growths, either naturally through adaptation or through genetic manipulation. Th e fi eld of oncolytic virus development has spanned approximately twenty years, with numerous viruses currently in clinical trials and in various stages of development as anti-cancer agents. Although oncolytic viruses exhibit diversity in their biologics and host range, oncolytic viruses share common features of selective replication in tumors, eff ective lysis of tumor cells, either directly or through activation of anti-tumor immunity, and dispersion within tumor masses. Strategies employed by viruses to target cancer cells include exploiting the defective antiviral responses in cancer cells, the use of cancer-specifi c surface markers as viral entry receptors, as well as the use of cancer-specifi c promoters to activate viral gene products. Many viruses that are currently being developed as agents against prostate cancers have taken advantage of these strategies.