Figure 7: VEGFR1⁺ bone marrow cells interact with ESCC cells to promote tumour growth and metastasis.

(a) Experimental scheme of bone marrow admixture-tumour xenograft model. Bioluminescence imaging (inset) showed absence of spontaneous metastasis in the lungs 2 weeks after the mice were subcutaneously injected with Luc-expressing KYSE150-Id1 cancer cells. (b) Representative photos and growth curves of tumours among the experimental groups (female 6–8-week-old nude mice, n=6 per group; scale bar, 1 cm). (c) Experimental scheme of the bone marrow admixture-experimental metastasis model (left panel); bioluminescence imaging and quantification of lung metastasis (right panel) (female 6–8-week-old nude mice, n=5 per group; scale bars, 200 μm and 100 μm for top and bottom rows of photomicrographs, respectively). (d) Experimental scheme of the bone marrow admixture-spontaneous metastasis model (left panel); bioluminescence imaging, macroscopic (arrows indicate visible metastases; scale bar, 1 cm) and microscopic pictures of the dissected lungs and quantification of lung weight (right panel) (female 6–8-week-old nude mice, n=5 per group; scale bars, 200 μm and 100 μm for top and bottom rows of photomicrographs, respectively). Bars, s.d.; *P<0.05; **P<0.01; ***P<0.001 by Student’s t-test.