Fig. 5

NAC-derived tumor exosomes reduce tumor growth and macrophage infiltration in nude mice. A. A2780 cells were injected into the flanks of 6-week-old female BALB/c nude mice. Tail vein injections of Exo-con or Exo-NAC (100 μg in 100 μl PBS) were performed every 3 days. Mice were terminated 21 days after the cell inoculation or the diameter of tumor reached 2.0 cm. B-C. Tumor growth curve and tumor weights are shown. N = 10 mice /group. D. The proportions of macrophages in tumors were measured by cell sorting (n = 5). E. Tumor tissues were sectioned and analyzed by IHC for macrophage marker F4/80 expression. Representative images of HE staining and IHC are shown (n = 5). Scale bar =200 μm. F. The miR-155-5p levels in tumor macrophages and splenic macrophages were measured by RT-qRCR (n = 4–5). G. Tumor tissues were sectioned and analyzed by IHC for PD-L1 expression. Representative images of IHC are shown (n = 5). Scale bar = 200 μm. H. Tumor macrophages and splenic macrophages were sorted and analyzed by flow cytometry for PD-L1 expression (n = 5). Isotype control: IgG. Data = Mean ± SD. *p < 0.05, **p < 0.01