Fig. 1
Melanoma cell lines differ in liver colonization efficiency and in the number of hepatic metastases. A–C WT31 (high metastatic), B16F10 luc2, RET (intermediate metastatic), D4M and HCmel12 (low metastatic) melanoma cells were injected intrasplenically at indicated cell numbers (0.1, 0.3 or 0.5, 1.0, 1.5 × 105 cells). Only D4M and HCmel12 were injected with 3.0 × 105 cells. Mice were sacrificed at day 14 (WT31, B16F10, RET, D4M, HCmel12) or at day 21 (RET, D4M, HCmel12). A pooled analysis of day 14 and day 21 is presented. Macroscopic visible liver metastases were counted. The percentage of mice with hepatic metastases (efficiency of hepatic colonization) and the number of macroscopic liver metastases are displayed. Representative images of colonized livers are shown. Scale bars = 1 cm. For detailed statistical analysis refer to Additional file 2: Table S1 and S2. D. WT31 melanoma cells were injected intravenously at indicated cell numbers (1.25, 1.75, 2.5 × 106). Mice were sacrificed at day 19. Macroscopic visible liver metastases were quantified. The percentage of mice with hepatic metastases (efficiency of hepatic colonization) and the number of macroscopic liver metastases are shown. A representative image of a liver with WT31 melanoma metastases is presented. Scale bar = 1 cm. For detailed analysis refer to Additional file 2: Table S3