Fig. 1

EV-dead induces TNBC lung metastasis and promotes TAM infiltration in vivo. A Diagram of the EV-dead and EV-alive separation procedures and their representative transmission electron microscopy (TEM) images. Scale bar: 100 nm. The sizes of the EVs were detected using a Flow NanoAnalyzer, and their protein markers were identified by Western blotting analysis. B NTA analysis was conducted to detect the relative secretion content of EV-dead and EV-alive; n = 3. C Representative images of zebrafish breast cancer xenotransplantation model assay. The effects of EV-alive (100 μg/ml) and EV-dead (50–100 μg/ml) on the metastasis of 4 T1 cells in the presence or absence of M0 co-injection were investigated; n = 6. D Schematic diagram of the animal assay and representative pictures of the in vivo imaging assay and tumors. Peritumoral injection with EV-dead (200 μg/20 g weight, q3d) promoted tumor growth of 4 T1-Luc xenografts, as evidenced by increases in both tumor volume and weight, but had no significant effect on the weight of the mice; n = 8. Scale bar: 1 cm. E Representative images of the lungs and the lung HE staining assay. Metastatic foci were identified by HE staining of the lung sections. Scale bar: 100 μm; n = 3. F Infiltration levels of CD45⁺/F4/80⁺/CD206⁺ TAMs in mammary tumors; n = 3. G Expression levels of ARG1 and iNOS in mammary tumor tissues; n = 3. Data are presented as mean ± SD. ^*p < 0.05, ^**p < 0.01