The influence of PRI-2191 on the antitumor activity of 5-FU in MC38 colon cancer. PRI-2191 was administered at a dose of 1 μg/kg/day, s.c., three times a week, from days 9 to 44, 5-FU at a dose of 100 mg/kg/day, i.v., from days 8 to 38. Black arrows indicate the days of 5-FU administration, gray arrows – days of PRI-2191 administration. A) Kinetics of tumor growth (mean of tumor volume). P < 0.05: 5-FU combined with PRI-2191 in comparison to the control from days 18 to 25 (Kruskal-Wallis ANOVA Multiple Comparisons P values (2-tailed) test). B) Tumor growth inhibition (TGI) and hypothetical TGI values were calculated from days 8 to 32 of the experiment (median of tumor volume). C) Survival analysis of treated and untreated mice. Number of mice: control – 7; 5-FU – 7, PRI-2191 – 5; 5-FU + PRI-2191 – 6.