Figure 4. CircRNA hsa_circ_0006215 promotes angiogenesis of HUVECs. Effects of BMSCs culture supernatant migration after overexpression and knockdown of hsa_circ_0006215 on (A) HUVECs using scratch assays, (B) HUVECs invasion using Transwell™ assays, and (C) tube formation. (D) Effects of overexpressed and knocked down hsa_circ_0006215 on expression of angiogenesis-related factors in BMSCs culture supernatant detected by ELISA. Quantitation of (E) tube formation, (F) scratch assays and (G) transwell assays. Results are expressed as means ± SD of three independent experiments. *p < 0.05, **p < 0.01.