Fig. 6

CRC cell-derived exosomal miR-934 induces M2 polarization of macrophages to promote invasion and liver metastasis of CRC cells in vitro and in vivo. a, b The CRC cell lines SW480 and RKO were cocultured with CM from PMA-treated THP-1 cells for 12 h (THP-1 cells were pretreated with exogenous miR-934 mimics). The effects of exogenous miR-934 on the migratory and invasive abilities of SW480 (a) and RKO (b) cells were tested using transwell assays. HCT-8 and HT-29 cells were transfected with anti-miR-934 or miR-934 mimics or their controls; exosomes were isolated from all groups. THP-1 cells prestimulated with PMA were treated with these exosomes at a concentration of 25 μg/mL or PBS; then, the CM were obtained and incubated with SW480 or RKO cells for 12 h. Migration and invasion in vitro (c, d) and liver metastasis in vivo (e–g) were evaluated using transwell assays and live imaging combined with HE staining, respectively (*p < 0.05; **p < 0.01; ***p < 0.001)