Fig. 6: Egr1⁺ neutrophils drive angiogenesis to accelerate KIAA1199-mediated colorectal liver metastasis.

A Subcutaneous tumor growth in mice co-injected with CRC cells and either Egr1⁺ or control neutrophils. Tumor volume was monitored for 21 days. Inset shows representative tumors at endpoint (n = 5 mice, two-way ANOVA). B CD31 immunofluorescence (green) and vascular density quantification in subcutaneous tumors. Yellow arrowheads indicate endothelial structures (n = 5 mice, Student’s t test). Scale bars: 100 µm. C mIHC of pre-metastatic livers (day 14) showing spatial association of Egr1⁺ neutrophils (white arrowheads) and CD31⁺ vessels (yellow arrowheads). Scale bars: 100 µm. D, E Co-localization analysis of Egr1⁺ neutrophils and CD31⁺ vasculature in mouse (D, n = 2 mice) and human (E, n = 2 patients) CRLM samples, highlighting the tumor boundary. Scale bars: 100 µm. F, I SVEC4-10 endothelial cell viability (CCK-8) (n = 3 independent experiments, Student’s t test). G, J Endothelial functional assays using supernatants from triple co-cultures treated with Rog or WRW4 (n = 3 independent experiments, Student’s t test). H, K Endothelial migration (scratch wound assay) (n = 3 independent experiments, Student’s t test). L Representative tube formation images (HUVEC and SVEC4-10) treated with neutrophil-conditioned media (n = 3 independent experiments). Scale bars: 20 µm. M, N Quantification of vessel numbers (M) and junction points (N) (n = 3 independent experiments, Student’s t test). Where applicable, all statistical tests are two-sided. Data are presented as mean ± s.d. Source data and exact p values are provided as a Source Data file.