Fig. 4

Exosomal circTUBGCP4 promotes HUVECs tip cell formation, migration, and tube formation. a CircTUBGCP4 expression was detected in HUVECs treated with HCT116-Exo and SW480-Exo at 0 h, 6 h, and 12 h. b The stable silencing effect and specificity of circTUBGCP4 in HCT116 and SW480. Effect of exosome of shcircTUBGCP4-01 (shCirc-01) and shcircTUBGCP4-02 (shCirc-01) derived from HCT116 and SW480 stable cell lines on tube formation ability and migration ability of HUVECs using tube formation assay (c), migration transwell assay (d), and wound healing assay (e and f). Then wound healing percentage (%) and the number of migrated cells and nodes were analyzed by Image J and Prism 9. g The CD34, integrin β1, and VEGFA expression of HUVECs treated with HCT116-exosome derived from shcircTUBGCP4-01 and shcircTUBGCP4-02 stable cell lines were detected by Western blot. GAPDH was the internal control of whole-cell lysates. h The CD34 expression of HUVECs treated with HCT116-exosome and SW480-exosome derived from shCirc stable cell lines were detected by immunofluorescence using a confocal microscopy image. HUVECs incubated with PBS and shNC-Exo was used as a negative control. Mean ± SEM. Student's t-test, *P < 0.05, 0.001 < ** P < 0.01, *** P < 0.001