Fig. 6

ESCC-derived exosomal miR-301a-3p inhibits PTEN and activates the PI3K/AKT pathway to induce the M2 polarization of macrophages, which then secrete VEGFA and MMP9 to promote angiogenesis. a 3′UTR sequence of PTEN has potential latent binding sites with the miR-301a-3p sequence. b Dual-luciferase reporter assay confirming the interaction of PTEN with miR-301a-3p. c PTEN expression in 20 pairs of fresh ESCC tissues and corresponding adjacent normal esophageal mucosa tissues was measured using qRT-PCR. d The relationship of miR-301a-3p expression with PTEN expression was analyzed with correlation analysis. e, f The expression of PTEN, PI3K, and AKT in macrophages incubated with ESCC cell-derived exosomes was measured using western blot and qRT-PCR. g, h The expression of VEGFA and MMP9 in macrophages incubated with ESCC cell-derived exosomes was measured using western blot and qRT-PCR. i The expression of VEGFA and MMP9 in the culture medium of macrophages incubated with ESCC cell-derived exosomes was measured using ELISA. j, k The expression of PI3K, AKT, VEGFA, and MMP9 in macrophages incubated with ESCC cell-derived exosomes and treated with the PI3K inhibitor LY294002 was measured using western blot and qRT-PCR. l, m The expression of PTEN, PI3K, AKT, VEGFA, and MMP9 in macrophages co-cultured with exosomes from EC9706 cells transfected with miR-NC, miR-301a-3p mimic, or miR-301a-3p inhibitor was measured using western blot and qRT-PCR. *p < 0.05, **p < 0.01, ***p < 0.001