ABSTRACT
To further investigate whether the suicide gene therapy affect the immune system, CT26 colon adenocarcinoma of BALB/c mice was adapted as experimental tumor model. The growth of CT26 tumor was suppressed by the adenovirus-mediated CD/5FC system significantly both in vitro and in vivo. But the tumors seemed very difficult to be cured and developed again soon after the end of treatment. After adenovirus-mediated CD/5FC gene therapy, there were about 40%of treated mice were cured from the tumor burden, survived longer and resisted further CT26 cell challenge. These mice also showed improvement of splenic CTL cytotoxicity. Costimulatory molecule B7-2, dendritic cell marker NLDC-145, MHC-I, and F4/80 were present in tumor mass in mice. These data suggested that in vivo suicide gene therapy could induce specific antitumor immunity, but this effect is not strong enough to eradicate established tumors. Further study for more efficient induction of antitumor immunity in CD/5FC gene therapy is warranted.