1 Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Peking Union Medical College Hospital, Center of Excellence in Tissue Engineering Chinese Academy of Medical Sciences, Beijing Key Laboratory (No. BZO381), Beijing, People's Republic of China.
2 Department of Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, People's Republic of China.
Stem Cells Dev. 2019 Apr 1;28(7):464-476. doi: 10.1089/scd.2018.0125. Epub 2019 Mar 5.
Mesenchymal stem cells (MSCs) are important components of the tumor microenvironment, which play an important role in tumor development. Exosomes derived from tumor cells can affect the biological characteristics of MSCs. Our study examined the effects of exosomes derived from gastric cancer cells on MSC immunomodulatory functions. Exosomes were extracted from gastric cancer cell line AGS (AGS-Exos) and cultured with MSCs. MSCs were then cocultured with both human peripheral blood mononuclear cells and macrophages [phorbol-12-myristate-13-acetate (PMA)-stimulated THP1 cells]. The activation levels of T cells and macrophages were detected by flow cytometry and real-time quantitative polymerase chain reaction (RT-PCR). Changes in the MSC signaling pathway after AGS-Exos stimulation were studied using RNA Chip, and the molecular mechanisms of functional change in MSCs were studied by inhibiting the signaling pathway. MSCs treated with AGS-Exos could promote macrophage phagocytosis and upregulate the secretion of proinflammatory factor, and promote the activation of CD69 and CD25 on the surface of T cells. RNA Chip results indicated the abnormal activation of the NF-kB signaling pathway in MSCs after AGS-Exos stimulation, and this was verified by the identification of key proteins in the pathway using western blot analysis. After NF-kB signaling pathway inhibition, the effect of MSCs stimulated by AGS-Exos on T cells and macrophages was markedly weakened. Therefore, AGS-Exos affected the immunomodulation function of MSCs through the NF-kB signaling pathway, which enhanced the ability of MSCs to activate immune cells, maintain the inflammatory environment, and support tumor growth.
间充质干细胞（MSCs）是肿瘤微环境的重要组成部分，在肿瘤发展中发挥重要作用。肿瘤细胞来源的外泌体可以影响 MSCs 的生物学特性。本研究探讨了胃癌细胞来源的外泌体对 MSC 免疫调节功能的影响。从胃癌细胞系 AGS（AGS-Exos）中提取外泌体并与 MSCs 共培养。然后将 MSCs 与人类外周血单个核细胞和巨噬细胞[佛波醇-12-肉豆蔻酸-13-乙酸酯（PMA）刺激的 THP1 细胞]共培养。通过流式细胞术和实时定量聚合酶链反应（RT-PCR）检测 T 细胞和巨噬细胞的激活水平。使用 RNA 芯片研究 AGS-Exos 刺激后 MSC 信号通路的变化，并通过抑制信号通路研究 MSC 功能变化的分子机制。用 AGS-Exos 处理的 MSC 可以促进巨噬细胞吞噬作用，并上调促炎因子的分泌，促进 T 细胞表面 CD69 和 CD25 的激活。RNA 芯片结果表明，AGS-Exos 刺激后 MSC 中 NF-kB 信号通路异常激活，通过 Western blot 分析鉴定该通路中的关键蛋白得到验证。抑制 NF-kB 信号通路后，AGS-Exos 刺激的 MSC 对 T 细胞和巨噬细胞的作用明显减弱。因此，AGS-Exos 通过 NF-kB 信号通路影响 MSCs 的免疫调节功能，增强 MSCs 激活免疫细胞、维持炎症微环境和支持肿瘤生长的能力。
