Fig. 1.
Intratumor administration of IL-12 and concomitant daily radiotherapy (RT) reduces the tumor volume (a) and extends the lifespan (b) of BALB/c mice-bearing CT26 colon cancer cells. Untreated CT26 tumors (seeded with 3 × 105 cells) were established in 6-week-old female BALB/c mice, as described previously [6]). The intratumoral administration of IL-12 was delivered at 10 µg/day for a period of 7 days, in the presence or absence of radiotherapy (RT) delivered to the tumor site at 2 Gy/day for a period of 7 days only. a Tumors treated concomitantly with IL-12 and RT were significantly smaller (Student’s t test; P < 0.001) than untreated tumors (treated with PBS, co) or those treated with either IL-12 or RT alone. b Mice treated concomitantly with IL-12 and RT survived longer than the untreated mice (co) or those treated with IL-12 or RT alone, as shown by a Kaplan–Meier survival plot (n = 14 animals/group; P < 0.05, log-rank test)