Fig. 3
IL12-encoded mRNA complexes exert antitumor effects on MC38-derived peritoneal carcinomatosis. (A) Survival of 5 × 105 MC38 i.p. tumor-bearing mice (n = 5–6/group) treated twice with PBS or mRNA-IL12 (10 µg/mouse) at days 10 and 13 or once with mRNA-Luc (20 µg/mouse), mRNA-IL12 (10 µg/mouse) or mRNA-IL12 (20 µg/mouse) on day 10 after tumor challenge. (B) MC38 cells (5 × 105) were injected subcutaneously into the mice 165 days after primary tumor challenge. Six naïve mice were used as a control group. The tumor follow-up data are shown. C‒F. MC38 cells (5 × 105) were administered i.p. to C57BL/6 mice (n = 4/group). The mice were treated i.p. twice with PBS, mRNA-Luc or mRNA-IL12 (10 µg/mouse) at days 10 and 13 after tumor inoculation. Eighteen hours after the second treatment, the mice were sacrificed, and spleen and peritoneal lavage samples were collected for further analysis. C-D. ELISAs were carried out with peritoneal lavage samples to detect IL12 and IFN-γ. E. Splenocytes were stimulated with p15E604 − 611 antigen or with 1 × 105 irradiated MC38 tumor cells (20,000 rads), and the number of IFN-γ–producing cells was measured via ELISpot. F. A representative ELISpot plate image. Log-rank (Mantel‒Cox) tests were used to analyze the survival data in panel A. The data from panel B are expressed as the means ± SDs, and repeated-measures ANOVA was used for the statistical analysis. Statistical significance was determined with one-way ANOVA followed by Tukey’s multiple comparisons tests in panels C and D. In panel E, two-way ANOVA followed by Tukey’s multiple comparisons test was performed. *p < 0.05, **p value < 0.01, ***p < 0.001, ****p < 0.0001