Figure 2. tPD-L1 selectively enhances metastasis independently of primary tumor growth.

A. Tumor growth curves (left) and final mass (right) of 4T1.scramble (4T1.WT, 5x10⁵ cells/mouse) and 4T1.PD-L1-KO (4T1.KO, 5x10⁵ cells/mouse) following orthotopic injection. Representative of three independent experiments. N= 5-15/condition. 2-way ANOVA. B. Tumor growth curve of CT26.scramble (CT26.WT, 1x10⁶ cells/mouse) and CT26.PD-L1.KO (CT26.KO, 1x10⁶ cells/mouse) following subcutaneous injection. N=5/condition. 2-way ANOVA. C. Growth curves (left) and final mass (right) of MC38-met.scramble (MC38-met.WT, 1x10⁶ cells/mouse) and MC38-met.PD-L1.KO (MC38-met.KO, 1x10⁶ cells/mouse) following subcutaneous injection. Representative of two independent experiments. N=10/condition. 2-way ANOVA. D. 4T1.WT and 4T1.KO spontaneous metastasis to the lung following orthotopic injection. N= 5-10/condition, two independent experiments. 2-way ANOVA. E & F. Quantification of 4T1 experimental metastatic foci by visual (E, N=15/condition) and microscopic (F, N=4/condition) inspection. Scale: 1 mm. The arrows point to tumor nodules present on the pleural surface. G & H. CT26.WT and CT26.KO cells were injected intravenously to BALB/c mice. Quantification of CT26 experimental metastatic foci by visual (G, N=10/condition) and microscopic (H, N=5/condition) inspection. Scale: 1 mm. The arrows point to tumor nodules. I. MC38-WT and MC38-met.KO cells were injected intravenously to C57BL/6 mice. Quantification of MC38-met experimental metastatic foci by visual inspection (N=8-9/condition). All data are presented in mean ± SD. See also Figure S3.