Development of a gene therapy method for cervical cancer using attenuated coxsackievirus B3 as a vector system

We previously reported the development of an attenuated coxsackievirus B3, known as YYFF, which functioned as a viral vector system for foreign gene expression. In this study, we demonstrated the potential use of YYFF as a gene therapy vector. Recombinant YYFF was constructed to express the human papillomavirus 16 (HPV16) E7 gene, referred to as YYFF-HPV16-E7. Growth of YYFF-HPV16-E7 resembled the wild type, YYFF, and it expressed HPV16-E7 in cell culture. When YYFF-HPV16-E7 was directly injected into TC-1-transplanted C57/BL6 mice, there was no reduction in tumor size, because of the non-growth of YYFF in C57/BL6 mice. However, when YYFF-HPV16-E7-induced immune cells/serum that originated from BALB/e mice was passively delivered into BALB/c background TC-1-transplanted nude mice, it reduced the size of cervical tumors in the nude mice. This study indicates the potential use of YYFF-HPV16-E7 as a gene therapy agent for treating HFV-induced cervical cancer.