Helicobacter pylori inhibits GKN1 expression via the CagA/p-ERK/AUF1 pathway
Helicobacter pylori inhibits GKN1 expression via the CagA/p-ERK/AUF1 pathway
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幽门螺杆菌通过 CagA/p-ERK/AUF1 通路抑制 GKN1 表达
DOI：
10.1111/hel.12665
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发表时间：
2019-10-27
期刊：
影响因子：
4.4
通讯作者：
Ding, Shigang
中科院分区：
文献类型：
--
作者：
Guo, Yanlei;Zhang, Ting;Ding, Shigang
背景近年研究表明，胃因子1 （gastrokine 1, GKN1）是一种重要的抑癌基因，在幽门螺杆菌感染的胃黏膜和胃癌中表达下调。然而，人们对其潜在机制知之甚少。在此，我们研究了幽门螺杆菌诱导GKN1下调的潜在机制。材料与方法采用实时荧光定量PCR、Western blot或免疫组化检测GKN1和富au元素rna结合因子1 （AUF1）在幽门螺杆菌感染组织和幽门螺杆菌共培养细胞系中的表达。通过RNA拉下法、RNA免疫沉淀法、mRNA转换法和荧光素酶活性法确定AUF1对GKN1的调控作用。磷酸化的细胞外信号调节激酶（p-ERK）或CagA参与幽门螺杆菌诱导的AUF1表达，使用p-ERK抑制剂或CagA敲除幽门螺杆菌验证。此外，我们还研究了auf1敲低细胞的细胞增殖和迁移能力。结果GKN1表达从幽门螺杆菌感染的胃炎到胃癌组织逐渐降低。幽门螺杆菌共培养也诱导GES-1和BGC-823细胞中GKN1显著降低。此外，GKN1和AUF1在人胃粘膜的mRNA水平呈显著负相关。AUF1敲低导致GKN1表达上调，并通过结合GKN1 mRNA的3 '非翻译区促进GKN1 mRNA的衰减。幽门螺杆菌诱导的AUF1表达与p-ERK激活和CagA相关。此外，敲低AUF1可显著抑制细胞活力和迁移能力，减少s期细胞滞留。结论幽门螺杆菌感染通过CagA/p-ERK/AUF1通路下调GKN1的表达。AUF1至少部分通过下调GKN1促进胃癌发生，这为胃癌治疗提供了新的潜在靶点。
Background Recent studies have shown that gastrokine 1 (GKN1), an important tumor suppressor gene, is downregulated in Helicobacter pylori (H. pylori) infected gastric mucosa and gastric cancer. However, the underlying mechanism is poorly understood. Herein, we investigated the potential mechanism of H. pylori-induced GKN1 downregulation. Materials and methods GKN1 and AU-rich element RNA-binding factor 1 (AUF1) expressions were assessed by quantitative real-time PCR, Western blot, or immunohistochemistry in H. pylori-infected tissues and H. pylori co-cultured cell lines. The regulation of AUF1 on GKN1 was determined by RNA pulldown assay, RNA immunoprecipitation, mRNA turnover, and luciferase activity assays. The involvement of phosphorylated extra-cellular signal-regulated kinase (p-ERK) or CagA in H. pylori-induced AUF1 expression was verified using p-ERK inhibitor or CagA knockout H. pylori. In addition, the cell proliferation and migration capacities of AUF1-knockdown cells were investigated. Results GKN1 expression progressively decreased from H. pylori-infected gastritis to gastric cancer tissues. H. pylori co-culture also induced significant GKN1 reduction in GES-1 and BGC-823 cells. Besides, the mRNA level of GKN1 and AUF1 in human gastric mucosa showed negative correlation significantly. AUF1 knockdown resulted in upregulation of GKN1 expression and promoted GKN1 mRNA decay by binding the 3 ' untranslated region of GKN1 mRNA H. pylori-induced AUF1 expression was associated with p-ERK activation and CagA. Furthermore, knockdown of AUF1 significantly inhibited cell viability, migration ability, and arrested fewer cells in S-phase. Conclusion Our data demonstrated that H. pylori infection downregulated GKN1 expression via the CagA/p-ERK/AUF1 pathway. AUF1 promoted gastric cancer at least partly through downregulating GKN1, which presented a novel potential target for the treatment of gastric cancer.