Fig. 3

High LAP-TGF-β1 protein levels in exosomes from pulmonary metastatic cells. (A) Volcano plot showcasing transcriptome shifts in LuECs after treatment with 231 LuT3 exosomes. Significant genes (p < 0.05, fold change > 1.5) highlighted. (B) Heatmap representation of gene expression shifts in LuECs post 24-hour exosome treatment. (n = 3). (C) KEGG pathway analysis for significantly altered genes upon exosome treatment. (D) GSEA for TGF-β pathway-enriched genes post exosome treatment. (E) Expression analysis of TGF-β1 and exosomal markers in a density gradient of 231 LuT3 exosomes in iodixanol (n = 3). (F) Comparison of active and inactive TGF-β1 forms in 231-derived exosomes (n = 3). (G) LAP-TGF-β1 concentration in exosome pellets. (n = 3). (H-J) GFP-Luc labeled 231-derived cells were injected into NCG-HLA-A2.1 mice, with tumors and plasma harvested 17 days later (n = 5). (H) Breast cancer orthotopic model schematic. (I) LAP-TGF-β1 levels in NCG-HLA-A2.1 mouse plasma exosomes (n = 5). (J) IF imaging of LAP-TGF-β1 and CD63 (n = 5). Scale bars: 100 μm and 30 μm. (K-L) Analysis of LAP-TGF-β1 and CD63 levels in cellular and exosomal proteins (n = 3). Data shown as mean ± SD