Effects of combined therapy with interleukin 2 and interleukin 12 gene-transfected tumor vaccine for head and neck carcinoma.

BACKGROUND The biological effects of cytokines are coming to be understood. The therapeutic effects of interleukin (IL) 2, IL-12, and interferon gamma (IFN-gamma) in cancer treatment have been reported, but there are problems when these cytokines are systemically used as therapeutic agents. OBJECTIVE To examine the efficacy of IL-2 and IL-12 gene-transfected tumor cell vaccines for head and neck squamous cell carcinoma (SCC). METHODS Homozygous mice with the autosomal recessive nude gene (BALB/c nu/nu mice) were inoculated subcutaneously in the right flank with cells from a human oral floor SCC cell line (KB cells). The mice were then injected with IL-2 and IL-12 gene-transfected KB cells (KB/IL-2 and KB/IL-12 cells, respectively) irradiated with 2000 rad (20 Gy). RESULTS No mice died soon after the injection of the gene immunotherapy. The treatment with either KB/human IL-2 (hIL-2) or KB/murine IL-12 (mIL-12) was not very effective. However, the treatment with both KB/hIL-2 and KB/mIL-12 cells significantly and safely inhibited the growth of established tumors (P =.04). There was no significant difference in antitumor effect between once-weekly and twice weekly injections of both KB/hIL-2 and KB/mIL-12 cells. CONCLUSION Double gene immunotherapy is safe and effective treatment for SCC in mice.