Fig. 7: G-CSF deficiency suppresses remodelling of the BM vascular niche and bone metastasis.

a Strategy to test the bone metastatic ability of G-CSF-deficient 4T1.2 cells. b Ex vivo fluorescence imaging of bones collected at experimental endpoint. Arrows point to metastasis in bone. c, d Quantification of photon flux (c) and bone metastasis area (d) from (b). Individual dots are from one bone. n = 11 (shCtrl) and 8 mice (shCsf3-1, shCsf3-2). In (c), **P = 0.0080, ***P < 0.0001. In (d), *P = 0.0126, ***P = 0.0003. P values, one-way ANOVA and Dunnett’s multiple comparisons test. e Representative 3D images (top) and enlarged micrographs (bottom) of femoral BM from mice injected with 4T1.2-shCtrl, 4T1.2-shCsf3-1 or 4T1.2-shCsf3-2 cells. Bones were stained for DAPI (grey), 4T1.2 cells (magenta), EMCN (yellow) and CD31 (cyan) (n = 5 mice per cell line). Arrowheads indicate endothelial sprouts. Scale bars: 300 µm (overviews), 10 µm (enlargements). f, g Quantification of surface area over length (f) and sprout length (g) of blood vessels from (e). Individual dots are from one vessel (f) or sprout (g). n = 3 mice per group. *P = 0.0116, **P = 0.0002, ***P < 0.0001 by one-way ANOVA and Dunnett’s multiple comparisons test. h–j Representative micro-computed tomography images (h) and morphometric analysis of tibial trabecula from metastasis-bearing mice. Data are presented as percentage of bone volume/tissue volume (BV/TV; %) (i) and trabecular thickness (Tb.Th; µm) (j). n = 5 mice per group. In (i), **P = 0.0016, ***P = 0.0002. In (j), *P = 0.0168, **P = 0.004. P values, one-way ANOVA and Dunnett’s multiple comparisons test. All data reflect mean ± s.e.m. Source data are provided as a Source Data file.