Oncolytic vaccinia virus inhibits human hepatocellular carcinoma MHCC97-H cell proliferation via endoplasmic reticulum stress, autophagy and Wnt pathways

Background Hepatocellular carcinoma (HCC) is a highly lethal malignancy. Vaccinia virus (VV) possessed many inherent advantages with respect to being engineered as a vector for cancer gene therapy, although the mechanism of action remains to be explored further. Methods We constructed a thymidine kinase gene insertional inactivated VV, named VV-Onco, and then tested its effects on cell viability, apoptosis and colony formation ability in a highly metastatic human hepatocellular carcinoma cell line MHCC97-H, and also investigated the potential cell signal pathways involved in this action. Results VV-Onco induced strong cytotoxicity and apoptosis and also inhibited the colony formation of MHCC97-H cells. The tumor cell apoptosis induced by VV-Onco is likely mediated via endoplasmic reticulum stress, autophagy and Wnt signaling pathways. The downregulation of survivin and c-Myc may also play a role in VV-Onco induced cell death. Conclusions The results of the present study provide new insights into the mechanisms of VV-induced tumor cell death. The engineered recombinant VV containing optimized therapeutic transgenes may represent a new avenue for cancer gene therapy. Copyright (C) 2016 John Wiley & Sons, Ltd.