Fig. 5

Pulmonary endothelium permeability in orthotopic murine 4T1 breast cancer model. a Evans blue (EB) deposition in lungs (see Methods), presented as mean ± SD. Black circle indicates outlier. Data analyzed with one-way ANOVA followed by Tukey’s multiple comparison test based on normality of distribution and homogeneity of variances; n = 20 for control and 1st and 3rd week; n = 18 for 2nd and 4th week; n = 10 for 5th week. Statistical significance vs healthy control group at *P < 0.05 and P** < 0.01. b–d Lung slices stained to visualize transcription factor Snail (see Methods), which is highly expressed in secondary nodules composed of metastatic 4T1 breast cancer cells. Black arrows point to pulmonary blood vessels of mice in 3rd (b), 4th (c), and 5th (d) week after 4T1 cancer cell inoculation to visualize that in 4th and 5th weeks some pulmonary vessels were occluded by metastatic cancer cells proliferating in their lumen. Scale bar represents 50 μm. e VEGFA and VCAM-1 expression determined by western blot analysis in pooled samples (n = 6) corresponding to healthy control and 4T1 breast cancer-bearing mice in 1st–5th week after 4T1 cancer cell inoculation (see Methods). Results presented as fold change vs control sample. Total protein after transfer was used as loading control. AU arbitrary units, VCAM vascular cell adhesion molecule, VEGFA vascular endothelial growth factor A