Interferon-Mediated Tumor Resistance to Oncolytic Virotherapy.

Interferons (INFs) elicit antiviral responses in tumor cells upon binding to cell surface receptors. Oncolytic virotherapy (OV) is an effective antitumor therapeutic approach which in combination with standard radiotherapy or chemotherapy regimens potentiates treatment responses in cancer patients. However, oncolytic viruses are susceptible to the IFN-induced antiviral state in the tumor microenvironment. A number of studies have, therefore, investigated the effects of combined therapy of IFN signaling pharmacological inhibitors with oncolytic viruses, which result in improved virus replication and oncolysis. This review summarizes the current knowledge of the mechanisms of interferon-mediated tumor resistance to oncolytic virotherapy and provides new insights regarding the effectiveness of combinatorial treatment strategies to attenuate INF-induced OV resistance for greater clinical significance in the treatment of cancer patients. J. Cell. Biochem. 118: 1994-1999, 2017. © 2017 Wiley Periodicals, Inc.