Fig. 6a–d.
The immunotherapy of preestablished B16-MAGE-1 melanoma (a and c) and B16 melanoma (b and d) with DNA vaccination. Groups of mice were s.c. inoculated with a lethal dose of B16-MAGE-1 and B16 tumor cells on day 0 (1×106 cells/mouse, respectively). Mice were immunized with 100 μg of various DNA vaccines (or PBS) on days 3 and 10. Tumor growth kinetics (a and b) were followed over time by caliper measurements, and mean tumor volumes (in mm3) were calculated. Error bars depict SE (n=6 mice/group). For a, MAGE-1-HSP70 fusion DNA vaccines give in statistically significantly better results than all other vaccines from day 24 (p<0.05, n=6), and MAGE-1 DNA and a mixture of MAGE-1 DNA and HSP70 DNA were significantly better than PBS on day 28 (p<0.05, n=6). For b, the difference between MAGE-1-HSP70 versus B16 and MAGE-1-HSP70 versus B16-MAGE-1 was significant from day 21 (p<0.05, n=6). Kaplan-Meier curves (c and d) were generated from survival data (n=6 mice/group). For c, MAGE-1-HSP70 vaccination versus PBS mock vaccination (p<0.01); versus MAGE-1 (p<0.05); versus HSP70 (p<0.05); versus MAGE-1 mixed with HSP70 (p<0.05; while all other comparisons were n.s. Median survival times for each treatment group: PBS, 36 days; pcDNA3, 38 days; MAGE-1, 47 days; HSP70, 41 days; MAGE-1-HSP70, 60 days; MAGE-1 mixed with HSP70, 44 days. For d, MAGE-1-HSP70 vaccination against B16-MAGE-1 tumor cells was significantly better than against B16 (p<0.01). Median survival times were 40 days for MAGE-1-HSP70 against B16, and 36 days for PBS against B16