Oncolytic virotherapy for oral squamous cell carcinoma using replication-competent viruses

Oncolytic virotherapy utilizes viruses that can selectively destroy cancer cells without harming normal tissues. Clinical trials of oncolytic viruses show that most oncolytic agents are well tolerated and safe. The virotherapeutic agents currently in use have limited potency when administered alone; however, combination therapy using virotherapeutic agents and conventional anticancer agents, such as chemotherapeutics, radiation, and gene therapy, exhibits encouraging levels of efficacy. Advances in recombinant DNA technology have allowed the development of viruses that are tumor-selective and armed with transgenes, increasing the application potential and efficacy of this novel anticancer therapy. Here, we review the development of oncolytic viruses and the clinical trials of oncolytic virotherapy for oral cancers. We discuss current issues and perspectives of this evolving anticancer therapy, highlighting the potential applications of a unique, naturally occurring oncolytic virus, Sindbis virus.