OBJECTIVETo evaluate the efficacy of combined interleukin (IL)-2 gene and IL-12 gene therapy in murine model with head and neck squamous cell carcinoma (HNSCC).

METHODSHNSCC model was established in the mouth floor of C3H/HeJ mice with SCCVII cell line. Lipid-IL2 and lipid-IL12 plasmid complexes were introduced either alone or in combination into the tumor by direct intratumor gene injection. Tumor size was measured before and after the treatment to evaluate the response of the different treatment and control groups. Enzyme-linked immunosorbent assay (ELISA) was used to measure the IL-2 and IL-12 expression. Lactic dehydrogenase (LDH) assay was used to evaluate the activity of Cytotoxic T-Lymphocyte (CTL) and natural killer (NK) cells.

RESULTSGrowth of HNSCC was significantly inhibited in combined IL-2 and IL-12 gene therapy group as compared with the other groups (P < 0.01). Increased level of IL-2 and IL-12 protein expression was found in both combined and single treatment groups. Greater activity of CTL and NK was also observed in these two groups as compared with the controls.

CONCLUSIONBoth IL-2 and IL-12 gene therapy is able to inhibit the growth of HNSCC and induce the host antitumor immune response efficiently in the murine model. Combination of the two in gene therapy may be additive or synergistic in antitumor effect.