CCL5 enhances metastasis of murine and human tumor cells. (A) Survival of MC-38GFP cells in lungs of mice treated with Met-RANTES and killed 48 hours after tumor cell injection (n = 3). (B) Met-RANTES attenuates metastasis of MC-38GFP cells. Mice were treated with Met-RANTES for 48 hours after tumor cell injection and killed 3 weeks later. The extent of metastasis was determined by GFP measurement. (C) Metastasis of LS180 human tumor cells in athymic mice treated with Met-RANTES for 48 hours after tumor cell injection and killed 5 weeks later. Histologic evaluation of mouse lungs from mice injected with LS180 cells for the presence of tumor nodules. (D) Metastasis of LS180 and HT-29 tumor cells in mouse lungs was determined by quantitative RT-PCR analysis of human EpCAM expression and normalized to murine GAPDH levels. **P < .01, ***P < .001 by 2-tailed Student t test; ns indicates not significant. (E) Representative images of hematoxylin-eosin–stained lung sections from mice injected with LS180 cells. Bar represents 100 μm.