Objective: To explore an efficient approach to enhance antitumor effect of suicide gene therapy by improving in vivo antigen presenting function and their immunological mechanisms.
Methods: The CT26 colon adenocarcinoma was treated with CD/5FC system combined with the mGM-CSF or/and mSCF gene transfection, and the antitumor effects were evaluated by the tumor growth, tumor-free mouse rate, splenic CTL activity and cytokine expression of tumor milieu.
Results: The tumor burden was reduced significantly and higher survival rate was obtained after the combined treatment. It was found that some cytokines(including mIL-4, mIL-2, mIFN-gamma and mTNF-alpha) were expressed in the tumor milieu after mGM-CSF or/and mSCF gene transfection following CD/5FC treatment but not in the control groups. The cytotoxic activity against CT26 cells of spleen cells of the treated mice was significantly incressed.
Conclusion: The combination of mSCF or/and mGM-CSF gene transfection enhances the antitumor effect of the suicide gene therapy. Such an enhancement is associated with the induction of specific antitumor immune response and secretion of cytokines in tumor milieu.