A novel strategy to compensate the disadvantages of live vaccine using suicide-gene system and provide better antitumor immunity.

Fusing dendritic cells (DCs) with tumor cells is a powerful vaccine to increase tumor immunogenicity. To develop more effective and safer therapeutic vaccine, we fused rat bone marrow-derived DCs with ovarian tumor cell line NuTu-19 modified by suicide gene (HSV1-TK gene) to obtain live vaccine against ovarian cancer. Our data showed that immunization of rats with such live vaccine solicited stronger ovarian tumor-specific cytotoxic T lymphocyte responses and induced immunopreventive and immunotherapeutic effects against parental tumor cells in vivo. Live vaccine could be induced to death after ganciclovir administration in vitro and in vivo. Our researches suggest that live vaccine modified with suicide gene might be effective and controllable in the therapy of ovarian cancer.