Exosomal M6PR mediates the effect of SRGN on angiogenesis in vitro and in vivo. (A) Effect of M6PR Exo on tube formation ability of HUVECs. Scale bar, 200 μm. Data are presented as mean ± SD. n = 7. ***, P < 0.001. (B) Western blot analysis of M6PR in cell lysates, CM and exosomes of ESCC cells with manipulated SRGN and M6PR expression. (C) Representative images of HUVECs treated with indicated CMs from ESCC cells. Scale bar, 200 μm. (D) Quantification of the numbers of nodes, junctions, segments and meshes in (C). Data are presented as mean ± SD. n = 8 and 3 for KYSE150 and KYSE410, respectively. *, P < 0.05; ***, P < 0.001. (E) Representative images of HUVECs treated with indicated Exo from ESCC cells. Scale bar, 200 μm. (F) Quantification of the numbers of nodes, junctions, segments and meshes in (E). Data are presented as mean ± SD. n = 6. *, P < 0.05; **, P < 0.01; ***, P < 0.001. (G) Effects of exosomes from ESCC cells with SRGN overexpression and M6PR-knockdown and rhM6PR on in vivo angiogenesis. Data are presented as mean ± SD. n = 4. *, P < 0.05.