Abstract
Soft tissue sarcomas pose a challenge for successful treatment with conventional therapeutic
methods, therefore newer therapeutic approaches are considered. In this study, we evaluated
the antitumor effect of IL-12 electrogene therapy (EGT) on murine SA-1 fibrosarcoma. The
Therapeutic plasmid was injected either intratumorally into subcutaneous SA-1 nodules or
intradermally into the peritumoral region. We achieved a remarkable local and systemic
antitumor effect with both approaches after single plasmid DNA application, with significant
intratumoral and systemic production of IL-12 and IFN-γ. Intratumoral IL-12 EGT resulted in
over 90% complete response rate of the treated tumors with 60% of cured mice being resistant
to challenge with SA-1 tumor cells. Peritumoral EGT resulted in a lower complete response
rate (16%), with significant growth delay of remaining tumors. Both therapies also resulted in
significant inhibition of growth of untreated tumors, growing simultaneously at a distant site.
These data suggest that IL-12 EGT may be useful in the treatment of soft tissue sarcomas,
exerting a local and systemic antitumor effect.