幽门螺杆菌通过激活Tim-3/Galectin-9参与胃癌发生的机制研究

Chronic inflammation promotes tumor development, progression, and metastatic dissemination, as well as treatment resistance. Gastric cancer (GC) is one of many cancers associated with inflammation, which is induced by Helicobacter pylori (Hp) infection, yet the mechanism is not clear until recently. Altered expression of Tim-3 and its ligand Galectin-9 is frequently associated with malignant transformation. Tim-3 expression was increased in immune cells and tumor cells, our previous studies also showed that the high expression of Tim-3 in tissue and urine samples in GC patients, but the mechanism is not clear until recently. We also detected elvated Tim-3 expression in Hp infection. Studies showed that Tim-3/Galectin-9 mediates activation of mTOR/HIF-1α pathways in human myeloid leukaemia cells, upregulating glycolysis and pro-angiogenic responses. Hp activates mTOR might impacting Hp-related gastric pathophysiology. Therefore, this study observes the relationship between Hp, Tim-3, Galectin-9 and mTOR/HIF1α pathway in co-culture model, GC patient samples, GC lines with antibody blocking/inhibitor and PDX model. To elucidate the role of Hp, Tim-3 Galectin-9 and mTOR/HIF1α in glycolysis and proliferation in GC, thus provide theoretical and experimental bases for GC therapy.

慢性不可控性炎症在肿瘤发生发展中起重要作用，幽门螺杆菌（Hp）感染与胃癌发生密切相关，其作用机制不甚清楚。Tim-3在肿瘤细胞中高表达且与患者预后相关，其配体Galectin-9也在肿瘤发生发展中起重要作用。我们前期发现，Hp感染可上调淋巴细胞中Tim-3表达，且胃癌患者组织和尿液标本中Tim-3高表达，但其作用机制未见报道。有研究提示Hp可激活mTOR信号通路参与胃癌发生发展，另Tim-3/Galectin-9可激活mTOR/HIF-1α促进糖酵解。因此我们推测Hp通过Tim-3/Galectin-9激活mTOR/HIF-1α通路，促进糖酵解参与胃癌增殖。本项目拟通过Hp和胃癌细胞共培养、人胃粘膜标本、抗体阻断和抑制剂处理、肿瘤组织异种移植模型研究Hp、Tim-3、Galectin-9和mTOR/HIF1α信号通路的关系，阐明其参与糖酵解和胃癌增殖的作用，为临床胃癌治疗提供理论依据。

慢性不可控性炎症在肿瘤发生发展中起重要作用，幽门螺杆菌（Hp）感染与胃癌发生密切相关，其作用机制不甚清楚。Tim-3在肿瘤细胞中高表达且与患者预后相关，其配体Galectin-9也在肿瘤发生发展中起重要作用。我们前期发现，Hp感染可上调淋巴细胞中Tim-3表达，且胃癌患者组织和尿液标本中Tim-3高表达，但其作用机制未见报道。在此研究中我们对Hp通过Tim-3/Galectin-9参与胃癌增殖的机制进行研究。.首先，我们进行Hp感染和胃癌Tim-3/Galectin-9的表达相关性研究。研究表明Tim-3和Galectin-9在胃癌细胞系的表达明显高于永生化胃上皮细胞，Tim-3和Galectin-9的表达在肿瘤组织的表达显著高于对应的正常胃黏膜组织且Tim-3在肿瘤组织的表达与癌旁组织Hp感染相关。Tim-3和Galectin-9在Hp共培养胃癌细胞系中表达升高，且Hp抑制胃癌细胞凋亡。.其次，我们进行Tim-3/Galectin-9激活mTOR/HIF-1α通路促进糖酵解参与胃癌增殖的机制研究。研究表明，胃癌细胞系中Tim-3/Galectin-9的表达上调， PI3K/Akt、mTOR/HIF-1α的表达上调，PI3K/Akt通路激活。在Hp共培养胃癌细胞中，葡萄糖转运蛋白GLUT1和糖酵解酶系（HK2、PFK2和PKM2）的表达上升。在Hp共培养胃癌细胞中，S期比例增高，凋亡细胞比例增高。加入Galectin-9、抗Tim-3抗体或mTOR抑制剂处理后，S期比例下降，凋亡细胞比例下降。在Hp共培养胃癌细胞中加入Galectin-9或抗Tim-3抗体后细胞的胞外酸化率（ECAR）下降。提示Hp通过Tim-3/Galectin-9激活mTOR/HIF-1α通路，促进糖酵解参与胃癌增殖。.最后，我们进行Hp感染和Tim-3/Galectin-9参与胃癌增殖的新的分子机制研究。研究表明胃癌细胞系中NF-κB、HIF-1α、ERK和pERK的表达上调。在Hp共培养胃癌细胞中加入Galectin-9或抗Tim-3抗体后，用蛋白质组学非标记定量的方法筛选获取Hp 感染中Tim-3/Galectin-9 可能的其他下游分子NGLY1。.本项目研究Hp、Tim-3、Galectin-9和mTOR/HIF-1α信号通路的关系，阐明其参与糖酵解和胃癌增殖的作用，为临床胃癌治疗提供