Figure 1.

Effect of voluntary exercise on the growth of pancreas Panc-1 and prostate PC-3 tumors in SCID mice. Female SCID mice were injected subcutaneously with human pancreas cancer Panc-1 cells (2.0 × 10⁶ cells/mouse), and male SCID mice were injected subcutaneously with human prostate cancer PC-3 cells (2.0 × 10⁶ cells/mouse). Both male and female mice were randomly assigned into two groups. One group was placed in cages (5-6 mice/cage) equipped with running wheels (1 running wheel/cage) one week before the injection of tumor cells, and the running wheels remained until the end of the study (56 days after the tumor cell injection). Mice in another group were in cages without a running wheel (5-6 mice/cage). Starting at day 21 after tumor cell injection, tumor size (length × width; cm²) per mouse was measured once a week until the end of the experiment. In A, tumor size was measured in the control group for all 10 tumors on each day as indicated. In the running wheel group, tumor size was measured on day 21 (N=10), days 28, 35 and 42 (N=11) and on days 49 and 56 (N=12). In B, tumor size was measured in the control and running wheel groups in all 10 tumors on each day as indicated. Each value represents the mean ± S.E.