Fig. 2.

Macrophage-derived GPNMB increases the lung colonization of GPNMB-deficient MCA-1 tumor cells. a Conditioned medium (CM) from DBA/2J GPNMB-deficient macrophages (CM-macro control) or from DBA/2J/Gpnmb⁺ macrophages containing GPNMB (CM-macro GPNMB) was concentrated >100× in 25 µl. DBA/2J GPNMB-deficient mice inhaled concentrated macrophage-derived CM prior to injection i.v. with 10⁵ MCA-1 sarcoma cells (GPNMB-deficient). Untreated mice inhaled saline solution. b Increased lung colonization of tumor cells in mice that inhaled CM-macro GPNMB. Results are shown for two independent experiments (total of 13–14 mice per group), with each dot representing an individual mouse. c The same type of experiment was performed with the tumor cell supernatant from GPNMB-transduced cells (Sup MCA-1-GPNMB) or mock-transduced cells (Sup MCA-1-Mock cells). d Mice that inhaled GPNMB-containing tumor cell supernatant had more lung colonies. Statistical analysis: ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 (b, d One-Way ANOVA). Data are calculated as the mean ± SEM