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.
目的: 探讨非小细胞肺癌（NSCLC）细胞外泌体源性FZD10在血管生成中的作用及其机制。
方法: 采用超速离心法分离外泌体，并利用Western blot和RT-qPCR技术分析NSCLC细胞（95D和H1299）、正常人支气管上皮细胞（BEAS-2B）及其外泌体中FZD10的表达；通过转染FZD10-siRNA敲低FZD10表达，用FZD10未敲低和敲低的NSCLC细胞外泌体分别处理HUVEC细胞，利用体外血管生成实验观察其成管能力，采用ELISA和RT-qPCR技术分析血管生成相关因子VEGFA和Ang-1的表达；进一步利用Western blot分析外泌体源性FZD10对信号通路PI3K、Erk1/2和YAP/TAZ激活的影响。
结果: 同BEAS-2B细胞及其外泌体相比较，FZD10在95D和H1299细胞及其外泌体中高表达（P < 0.01）；95D和H1299细胞来源的外泌体可促进HUVEC的微管形成及VEGFA、Ang-1的蛋白分泌、mRNA的表达（P < 0.01），但在95D和H1299细胞敲低FZD10后这些效果受到抑制。FZD10的敲低可抑制PI3K、Erk1/2信号通路的激活，但对YAP/TAZ信号通路的影响不显著。
结论: NSCLC细胞外泌体源性FZD10可促进体外血管生成，其机制可能与PI3K、Erk1/2信号通路的激活有关。
Keywords: FZD10; angiogenesis; exosomes; non-small cell lung cancer.