Figure 6.

In four different experiments, mice were subjected to 8 h of restraint stress (A) or 12 h of tilt&light (B–D) stress. In experiments C and D, mice were administered with RU486 or vehicle 30 min prior to the onset of stress. In all experiments (A–D) mice were administered with CpG-C or vehicle 2 h after the onset of stress. (A–C) Plasma IL-12 levels were assessed at the end of each stress paradigm. (D) Visible hepatic metastases were counted 20 days later. (A, B) Restraint (n=31, n=7–9 per group) and tilt&light (n=36, n=7–10 per group) stress paradigms did not interrupt the CpG-C-induced elevation in plasma IL-12 levels. (C) Tilt&light stress significantly decreased plasma IL-12 levels (main effect, n=78, n=9–11 per group, P=0.0149) and (D) increased numbers of CT26 metastases (main effect, n=97, n=10–15 per group, P=0.0149), but did not prevent the beneficial effects of CpG-C on these indices: (C) increased IL-12 levels (main effect, P<0.0001, and (D) decreased CT26 metastases, main effect, P<0.0001). RU486 (C) did not negate the deleterious effects of stress on IL-12 levels, but (D) did improve the antimetastatic effects of CpG-C under stress conditions (P=0.0104) (*P<0.05). Boxes represent the second and third quartiles, and whiskers show min and max values.