Fig. 3. Absence of exosomal miR-25-3p inhibited IL-6 secretion from macrophages via NF-κB in a TLR7/8-dependent manner and then receded breast cancer cell viability and migration. Exosomes derived from tumor cells were introduced into THP-1, RAW264.7, THP-1 (TLR8^−/−), or RAW264.7 (TLR7^−/−) cells. About 48 h after incubation, RT-qPCR and ELISA assays were carried out to detect the mRNA (A and B) and protein levels (C–F) of IL-6. NF-κB activity was measured by ELISA assay (G and H). The viability (I and J) and migration (K and L) of MDA-MD-231 and E0771 cells treated with IL-6, vehicle, or MS previously incubated with hypoxia or miR-25-3p-lacked hypoxia exosomes were determined by MTT and Transwell assays.