Fig. 5

BCSC-derived IL8 drives metastasis. A, B GSEA analysis of basal-like A or EMT associated gene signature B or basal-like associated gene signature in TCGA breast cancer patients stratified according to their IL8 levels. C Transwell migration and invasion assay of MCF-7 and SUM159 cells treated with 100 ng/ml recombinant IL8. Scale bar: 300 μm. D Transwell migration and invasion assay of MCF-7 and SUM159 cells cultured with CM derived from respective parental cells or mammosphere-enriched BCSCs in the presence or absence of 0.1 mM repertaxin or 1 μg/ml IL8 neutralizing antibody. Scale bar: 300 μm. E Transwell migration and invasion assay of MCF-7 and SUM159 cells cultured with CM derived from parental cells or mammosphere-enriched shCONT-BCSCs or shIL8-BCSCs. Scale bar: 300 μm. F Immunoblot analysis of p-AKT and t-AKT in MDA-MB-231 cells cultured with CM from BCSCs or parental cells. G MDA-MB-231 cells were tail vein injected into nude mice and received repertaxin treatment for 3 weeks, the metastatic burden was determined by bioluminescent imaging. All experiments were repeated at least three times. Results are shown as mean ± S.D. *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant (Unpaired two-tailed Student’s t-test)