Fig. 5

HCC cell-secreted exosomal ANGPT2 promotes the angiogenesis capability of HUVECs in vitro. a HUVECs were cultured with or without HCC cell-secreted exosomes for 12 h. The Matrigel microtubule formation assay showed that ANGPT2-overexpressing exosomes significantly promoted tubule formation of HUVECs, and compared with control exosomes, ANGPT2-deficient exosomes abrogated exosome-induced tubule formation. b HUVECs were cultured with or without HCC cell-secreted exosomes for 12 h. The transwell migration assay showed that ANGPT2-overexpressing exosomes significantly promoted migration of HUVECs, and compared with control exosomes, ANGPT2-deficient exosomes abrogated exosome-induced migration. c HUVECs were cultured with or without HCC cell-secreted exosomes for 7 d and were counted by measuring the OD at 450 nm at 1, 3, 5, and 7 d. CCK-8 showed that HUVEC proliferation was significantly increased after coculture with ANGPT2-overexpressing exosomes, and compared with the coculture with control exosomes, ANGPT2-deficient exosomes abrogated exosome-induced proliferation. d HUVECs were cultured with or without HCC cell-secreted exosomes for 72 h. Immunoblotting showed that ANGPT2-overexpressing exosomes notably increased the levels of tumor angiogenesis-related proteins (CD31, CD105 and VEGFA) in HUVECs, and the promotional effect of ANGPT2-deficient exosomes on these angiogenesis-related proteins was notably reduced compared to the promotional effect of control exosomes. Scale bar = 200 μm. n = 6 for each group (a, b), n = 4 for each group (c, d), *P < 0.05, **P < 0.01, ***P < 0.001, one-way ANOVA with Tukey’s multiple comparison tests