Fig. 3

NSCLC cells preferentially release miR-4732-3p into exosomes. A Relative expression of miR-4732-3p, miR-92b-3p, and miR-1180-3p in NSCLC cells. B NSCLC cells was treated with GW4869 (10 μM) to assess the effects of exosome secretion on intracellular miRNA expression via qRT-PCR analysis and the proportion of each miRNA sorted into exosomes was calculated. C Images of fucosylated exosomes derived from NSCLC cells were photographed by transmission electron microscopy (TEM). Scale bar = 100 nm. D Western blot analysis was performed to detect typical exosome markers, including TSG101, CD9, and Calnexin (negative control). E Graphic illustration of co-culture system, in which we isolated fucosylated exosomes enriched with miRNA and added them into conditioned medium (CM) of NSCLC cells. F–H Fucosylated exosomes enriched with miR-4732-3p (F), miR-92b-3p (G), and miR-1180-3p (H) were obtained following transfecting NSCLC cells with miRNA mimics. I Internalization of PKH67-labeled fucosylated exosomes (green) by NSCLC cells. Scale bar = 10 μm. J-L NSCLC cells were co-cultured with blank control (PBS), or exosomes rich in miR-4732-3p, miR-92b-3p, and miR-1180-3p. We further added GW4869 (10 μM) to the co-culture system and analyzed the expression of intracellular miRNA in NSCLC cells co-cultured with exosomes under conditions where exosome secretion was suppressed, but exosome uptake was allowed. qRT-PCR was applied to verify the expression of miR-4732-3p (J), miR-92b-3p (K), and miR-1180-3p (L) in NSCLC cells after co-culturing. Data are shown as the mean ± SD from at least three independent experiments. ^*p < 0.05; ^**p < 0.01; ^***p < 0.001; ^****p < 0.0001; ns, not significant