Treatment of hepatitis C virus core-positive hepatocytes with the transfer of recombinant caspase-3 using the 2<italic>′</italic>,5<italic>′</italic>-oligoadenylate synthetase gene promoter

Hepatitis C virus (HCV) infection is a leading cause of liver-related morbidity and mortality throughout the world. There is no vaccine available and current therapy is only partially effective. Since HCV infects only a minority of hepatocytes, we hypothesized that induction of apoptosis might be a promising approach for the treatment of hepatitis C. In the present study, recombinant caspase-3 gene (re-caspase-3) was used because it has the ability to induce apoptosis that is independent of the initiator caspases. An HCV-specific promoter is required to regulate the cytotoxic caspase-3 expression in HCV-infected cells. It has been reported that HCV core protein can specifically activate the 2',5'-oligoadenylate synthetase (OAS) gene promoter in human hepatocytes. Therefore, we constructed an expression vector consisting of the re-caspase-3 under the OAS gene promoter (pGL3-OAS-re-caspase-3) and then investigated its effect on HCV core-positive liver cells. It was found that the pGL3-OAS-re-caspase-3 construct induced apoptosis in HCV core-positive liver cells, but not in normal liver cells. These results strongly suggested that the transfer of the re-caspase-3 gene under the OAS promoter was a novel targeting approach for the treatment of HCV infection.