EGFR Activation in H. Pylori-Induced Gastric Cancer

H.py/或/诱导的胃肿瘤发生与胃上皮细胞凋亡调节失调和 然而，管理这些细胞反应的机制尚不清楚。幽门螺杆菌致胃 表皮生长因子受体(EGFR)及其下游靶标ERK1/2的上皮细胞激活。 这些信号通路调节与肿瘤发生有关的细胞增殖和生存程序 其他系统和我们的数据现在表明，幽门螺杆菌激活EGFR可以减少细胞凋亡。我们的 初步研究结果还表明，需要去整合素和金属蛋白酶-(ADAM-)17的表达 幽门螺杆菌对EGFR的反式激活以及EGFR的激活介导H.py/Ori诱导的氧化应激 通过上调精胺氧化酶(SMO)。因此，我们假设EGFR的反式激活 是H.py/Ori介导的肿瘤发生机制中一个关键的分子调控步骤，启动 增强被这种病原体诱变的细胞的保留力的抗凋亡反应。 为了实现这一目标，设计了三个具体的目标：1.确定激活的机制 EGFR与幽门螺杆菌调控的分子相互作用。我们将重点关注亚当的要求- 17使用ADAM-17基因敲除和加回细胞系和特定的抑制剂激活EGFR。EGFR 相互作用的蛋白质将用Flag-EGFR沉淀，并通过MALDI-TOF分析进行鉴定。2.定义 表皮生长因子受体反式激活在H.py/或/介导的胃粘膜中的作用及下游靶点的确定 上皮细胞DNA损伤。我们将评估SMO作为EGFR下游目标的作用 转录激活，确定氧化损伤和DMA损伤，并使用2D-DGE识别下游 H.py/或/‘介导的EGFR反式激活的靶点。3.确定EGFR反式激活对 H.py/或/-介导的胃上皮细胞DNA损伤、凋亡、增殖和肿瘤发生 活着。将分析幽门螺杆菌感染患者的增殖、细胞凋亡、应激反应和癌前病变。 野生型和EGFR缺陷小鼠。这项研究的意义在于确定分子 H.py/或/-诱变背景下胃上皮细胞存活机制(S) 导致胃肿瘤发生的途径，这对于寻找H。 Py/Ori介导的疾病。此外，这些机制可能与许多炎症相关。 由于细胞增殖和凋亡程序的改变而引起的肠道疾病。

H. py/or/-induced gastric tumorigenesis is associated with dysregulation of gastric epithelial apoptosis and aroliferation; yet, the mechanisms that govern these cellular responses are unclear. H. pylori induces gastric epithelial cell activation of epidermal growth factor receptor (EGFR) and a downstream target, ERK1/2. These signaling pathways regulate cellular proliferation and survival programs implicated in tumorigenesis in other systems and our data now indicate that H. pylori activation of EGFR attenuates apoptosis. Our preliminary findings also show that a disintegrin and metalloproteinase- (ADAM-) 17 expression is required for EGFR transactivation by H. pylori and that activation of EGFR mediates H. py/ori-induced oxidative stress through up-regulation of spermine oxidase (SMO). Therefore, we hypothesize that transactivation of EGFR is a key molecular regulatory step in the pathogenesis of H. py/ori-mediated tumorigenesis, initiating anti-apoptotic responses that heighten the retention of cells mutagenized by this pathogen. Three Specific Aims are designed to achieve this goal: 1. Determine the mechanism of activation of EGFR and the molecular interactions regulated by H. pylori. We will focus on the requirement of ADAM- 17 for EGFR activation using ADAM-17 knockout and add-back cell lines and specific inhibitors. EGFR interacting proteins will be precipitated with Flag-EGFR and identified by MALDI-TOF analysis. 2. Define the contribution of EGFR transactivation and identify downstream targets in H. py/or/-mediated gastric epithelial cell DMA damage. We will assess the role of SMO as a downstream target of EGFR transactivation, determine oxidative injury and DMA damage, and use 2D-DIGE to identify downstream targets of H. py/or/'-mediated EGFR transactivation. 3. Determine the effects of EGFR transactivation on H. py/or/-mediated gastric epithelial cell DMA damage, apoptosis, proliferation, and tumorigenesis in vivo. Proliferation, apoptosis, stress responses, and cancer precursor lesions will be analyzed in H. pyloriinfected wild-type and EGFR-defective mice. The significance of this research is to determine the molecular mechanism(s) of H. py/or/-mediated gastric epithelial cell survival within the context of mutagenesis pathways leading to gastric tumorigenesis, which is important for identifying novel therapeutic targets for H. py/ori-mediated diseases. Furthermore, these mechanisms may be implicated in a number of inflammationassociated intestinal disorders resulting from altered programs of cellular proliferation and apoptosis.