Fig. 5. M2 macrophage-derived EVs downregulated METTL3 in PTC and ATC cells through miR-21-5p.

A Representative images of K1 and BHT101 cells with phagocytosed CSFE-labeled M2 EVs (scale bars, 50 μm). The cell nucleus were stained with DAPI. B, C METTL3 and CD70 mRNA and protein levels in K1 and BHT101 cells co-cultured with M2 EVs, co-cultured with THP-1 cells and cultured alone. D CD70 mRNA and protein levels in K1^oeMETTL3 and BHT101 ^oeMETTL3 cells co-cultured with M2 EVs. E Overlap between upregulated miRNAs in M2 EVs and predicted miRNAs targeting METTL3. F The expression of miR-21-5p in THP-1 EVs and M2 EVs. G, H METTL3 and CD70 mRNA and protein levels in K1 and BHT101 cells co-cultured with M2 EVs in the presence or absence of the miR-21-5p inhibitor. I Percentage of CD4⁺Foxp3⁺ Tregs, CD8⁺PD-1⁺Tim-3⁺ terminally exhausted T cells, CD8⁺GzmB⁺perforin⁺ T cells, CD8⁺TNF-α⁺ T cells and CD8⁺IFN-γ⁺ T cells in PBMCs co-cultured with M2 EVs-treated K1 and BHT101 cells expressing the miR-21-5p inhibitor. Data of are presented as the mean ± SD of three independent experiments. The p-values in (B), (D), (F), (G), (H) and (I) were calculated by Student’s t-test. *p < 0.05; **p < 0.01; ***p < 0.001.