OBJECTIVE: To investigate the effect of exosomal FZD10 derived from non-small cell lung cancer (NSCLC) cells on angiogenesis of human umbilical venous endothelial cells (HUVECs) and explore the possible mechanism. METHODS: We analyzed the expression of FZD10 in two NSCLC cell lines (95D and H1299 cells), normal human bronchial epithelial cells (BEAS-2B cells) and their exosomes isolated by ultracentrifugation. Cultured HUVECs were treated with the exosomes derived from NSCLC cells or NSCLC cells transfected with FZD10-siRNA, and the changes in tube formation ability of the cells were analyzed using an in vitro angiogenesis assay. ELISA was performed to determine the concentration of VEGFA and Ang-1 in the conditioned media of HUVECs, and RT-qPCR was used to analyze the mRNA levels of VEGFA and Ang-1 in the HUVECs. The effects of exosomal FZD10 on the activation of PI3K, Erk1/2 and YAP/TAZ signaling pathways were evaluated using Western blotting. RESULTS: Compared with BEAS-2B cells and their exosomes, 95D and H1299 cells and their exosomes all expressed high levels of FZD10 (P < 0.01). The exosomes derived from 95D and H1299 cells significantly enhanced tube formation ability and increased the expressions of VEGFA and Ang-1 protein and mRNA in HUVECs (P < 0.01), but FZD10 knockdown in 95D and H1299 cells obviously inhibited these effects of the exosomes. Exosomal FZD10 knockdown suppressed the activation of PI3K and Erk1/2 signaling pathways, but had no obvious effect on the activation of YAP/TAZ signaling pathway. CONCLUSION Exosomal FZD10 derived from NSCLC cells promotes HUVEC angiogenesis in vitro, the mechanism of which may involve the activation of PI3K and Erk1/2 signaling pathways.
Carcinoma, Non-Small-Cell Lung/metabolism* ; Cell Proliferation ; Culture Media, Conditioned ; Exosomes ; Frizzled Receptors/metabolism* ; Human Umbilical Vein Endothelial Cells/metabolism* ; Humans ; Lung Neoplasms/metabolism* ; MicroRNAs/genetics* ; Neovascularization, Pathologic/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; RNA, Messenger/metabolism* ; RNA, Small Interfering/metabolism*