Combined Interleukin 12 and Granulocyte-macrophage Colony-stimulating Factor Gene Therapy Synergistically Suppresses Tumor Growth in the Murine Fibrosarcoma

Interleukin (IL-12) and the granulocyte-monocyte colony-stimulating factor gene (GM-CSF) have been used as immunotherapeutic agents in cancer gene therapy as they activate dendritic cells and boost anti-tumor immune responses. IL-12 and GM-CSF have different roles in anti-tumor immune response.
The aim of present study was to investigate the anti-tumor effects of combined gene therapy with GM-CSF and IL-12 in a fibrosarcoma mouse model.
To investigate the combined therapeutic effect of GM-CSF and IL-12, WEHI 164 tumor cells were transfected with Murine GM-CSF (m-GM-CSF) and Murine IL-12 (m-IL-12) genes, using Lipofectamine. The fibrosarcoma mouse model was established by subcutaneous injection of transfected cells to Balb/c mice. Mice were sacrificed and the tumors were extracted. Tumor sizes were measured by caliper. The expression of GM-CSF, IL-12 and IFN-γ was studied by real-time PCR and immunoblotting. The expression of Ki-67 (a proliferation marker) in tumor masses was studied by immunohistochemistry staining.
The tumor size was reduced in IL-12 GM-CSF group (P Combination therapy with GM-CSF and IL-12 displayed significant therapeutic effects and represented a promising gene therapy strategy for cancer.