Regulatory T Cells Promote Overexpression of Lgr5 on Gastric Cancer Cells via TGF-beta1 and Confer Poor Prognosis in Gastric Cancer
Regulatory T Cells Promote Overexpression of Lgr5 on Gastric Cancer Cells via TGF-beta1 and Confer Poor Prognosis in Gastric Cancer
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DOI：
10.3389/fimmu.2019.01741
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发表时间：
2019-07-30
影响因子：
7.3
通讯作者：
Yu, Ji-Ren
中科院分区：
文献类型：
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作者：
Liu, Xiao-Sun;Lin, Xian-Ke;Yu, Ji-Ren
背景：富含亮氨酸重复序列的G蛋白偶联受体5(Lgr5)被认为是一种肿瘤干细胞标记物，常在肿瘤中过度表达。Lgr5与免疫相关的肿瘤微环境之间的相互作用尚不完全清楚。本研究旨在探讨Lgr5在胃癌微环境中的作用，探讨调节性T细胞调控Lgr5表达的可能免疫学机制。方法：采用免疫组织化学方法检测180例胃癌组织中Lgr5的表达，用双抗体夹心法检测80对胃癌组织中Th1/Th2细胞因子的表达。用不同浓度的转化生长因子-β1、转化生长因子-β1中和抗体或转化生长因子-β受体抑制剂SB431542与SGC7901细胞共同培养，用定量逆转录聚合酶链式反应和免疫印迹法检测Lgr5和β-catenin的表达。结果：在本研究中，免疫抑制的微环境与胃癌细胞高表达Lgr5有关。此外，在与Tregs共同培养或外源性转化生长因子-β1处理的GC细胞中，Lgr5的表达上调，这种上调可被转化生长因子-β1中和抗体或转化生长因子-β1受体拮抗剂SB431542部分抑制。外源性转化生长因子-β1诱导的Lgr5高表达可上调β-连环蛋白的表达，SB431542可抑制这种上调。结论：Tregs通过转化生长因子-β1和转化生长因子-β1信号通路促进胃癌细胞Lgr5表达增加，这可能与Wnt信号通路的激活有关。Lgr5通过转化生长因子-β的高表达与胃癌的预后不良有关。
Background: The leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5) is considered a cancer stem cell marker, and is often overexpressed in tumors. The interaction between Lgr5 and the immune-related tumor microenvironment is not completely understood. The aim of this study was to examine the role of Lgr5 in the microenvironment of gastric cancer (GC), and to explore possible immunological mechanisms influencing Lgr5 expression that are governed by regulatory T cells.Methods: Lgr5 expression was examined in 180 GC tumors by immunohistochemistry, and in 80 pairs of GC tumors for analysis of Th1/Th2 cytokines by ELISA. In addition, SGC7901 cells were co-cultured with patient-derived Tregs, varying concentrations of TGF-beta 1, TGF-beta 1 neutralizing antibody, or TGF-beta receptor inhibitor SB431542, and Lgr5 and beta-catenin expression were examined by qRT-PCR and western blot.Results: In this study, an immunosuppressive microenvironment was associated with high Lgr5 expression in GC. Furthermore, Lgr5 expression was up-regulated in GC cells co-cultured with Tregs or treated with exogenous TGF-beta 1. This up-regulation was partially inhibited by the TGF-beta 1 neutralizing antibody, or TGF-beta 1 receptor antagonist SB431542. beta-catenin was up-regulated with high Lgr5 expression induced by exogenous TGF-beta 1, and this up-regulation was inhibited by SB431542. An increased number of Tregs and high Lgr5 expression in GC tissues were significantly associated with low overall survival.Conclusion: Tregs promoted increased Lgr5 expression in GC cells via TGF-beta 1 and TGF-beta 1 signaling pathway, which may involve activation of the Wnt signaling pathway. High Lgr5 expression via TGF-beta confer poor prognosis in gastric cancer.