Abrogation of TNFα signaling does not affect IL-12 antitumor activity.

For subcutaneous tumor growth, 1×10⁶ B16 cells were injected s.c. in C57BL/6 (WT) and TNFR1 KO mice (8–10 weeks old). Between days 10–14, when tumors had reached a size of approximately 5 mm, mice were hydrodynamically injected with IL-12 cDNA. In the days post cDNA injection, tumor growth was measured with a caliper (upper panel). For liver metastases analysis, intrasplenic injection was performed on day 0 with 0.5×10⁶ B16 melanoma cells and 3 days later with IL-12 cDNA via hydrodynamic shear. Liver examination was performed on day 14 post treatment (lower panel). IL-12 vs control p values are plotted in the figure. The data in the upper panel are expressed as the mean of 2 different experiments with 4 mice per group. Pictures of the lower panel are representative of 2 different experiments with 4–5 mice per group.