Fig. 3

CRC cell-derived exosomal miR-934 induces M2 polarization of macrophages. a ClueGO analysis of the 191 genes showing the highest correlation with miR-934 using Cytoscape software. Enriched pathways are shown as nodes interconnected based on the κ score. b Correlation between miR-934 and specific gene signatures of different immune cells. The node size represents the association p value between the neighbor gene and miR-934. c IHC staining of TAMs (for the M2 macrophage marker CD163) in primary human CRC tissues and liver-metastatic tissues, n50. The red arrows indicate TAMs; the black arrows indicate tumor cells. Scale bar, 200 μm. The correlation between TAM infiltration and miR-934 expression is also shown. d Representative image of macrophages derived from THP-1 cells treated with phorbol 12-myristate 13-acetate (PMA) for 24 h. qPCR analysis of the expression of the macrophage marker CD68 was also performed. e Representative immunofluorescence image showing the internalization of DiO-labeled HT-29/HCT-8/Caco-2/LoVo-derived exosomes (green) by PMA-treated THP-1 cells. f qPCR analysis of the expression of typical M2 markers (CD206, arginase-1, and IL10) and M1 markers (iNOS and IL-1β) in PMA-pretreated THP-1 cells treated with HT-29/HCT-8/Caco-2/LoVo-derived exosomes or PBS (control) g Flow cytometry was performed to analyze the effect of CRC cell-derived exosomes on the expression of the typical M2 marker CD163. qPCR (h) and flow cytometry (i) were used to determine the effect of exogenous miR-934 on the expression of typical M2 markers in PMA-treated THP-1 cells. qPCR (j) and flow cytometry (k) were used to determine the effect of exosomes derived from HCT-8 and HT-29 cells transfected with anti-miR-934 on the expression of CD206, arginase-1, IL10, and CD163 (*p < 0.05; **p < 0.01; ***p < 0.001)