EphA2通过诱导IL6分泌增强鼻咽癌干性的作用及其机制研究

We recently used proteomics to screen the proteins relative to nasopharyngeal carcinoma (NPC) metastasis, and found that EphA2 promotes NPC metastasis and enhances in vitro NPC cells stemness. We also used inflammatory cytokines ELISA array to screen secretory cytokines induced by EphA2 in the NPC cells, and identified and validated that EphA2 induces IL6 secretion. To further investigate the role and molecular mechanism of EphA2-enhancing NPC stemness via inducing IL6 secretion, as well as its correlation with EphA2-promoting NPC metastasis, in this project the effects of EphA2 and its inducing secretory IL6 on NPC stemness will be determined; the effects of EphA2 on the activity of IL6/IL6R/JAK/Stat3 signaling pathway as well as its association with NPC stemness will be investigated; finally the correlation between EphA2-enhancing NPC stemness and its promoting NPC metastasis will be analyzed. Our expected results will not only be helpful to reveal the role and molecular mechanism of EphA2-enhancing NPC stemness, and the association of EphA2-enhancing NPC stemness with its promoting NPC metastasis, but also provide the target molecules for targeted NPC stemness and metastasis therapy, which has an important theoretical and practical significance.

我们前期采用蛋白质组学技术筛选鼻咽癌转移相关蛋白质，发现EphA2促进鼻咽癌转移并能增强体外鼻咽癌细胞的干性；采用ELISA array筛选EphA2调控鼻咽癌细胞分泌的炎性细胞因子，发现并证实EphA2诱导IL6的分泌。为研究EphA2是否通过诱导IL6分泌增强鼻咽癌干性的作用及其分子机制以及与EphA2促进鼻咽癌转移的关系，项目拟分析EphA2及其诱导分泌的IL6对鼻咽癌干性的影响，明确IL6介导EphA2增强鼻咽癌干性；分析EphA2对鼻咽癌细胞IL6/IL6R/JAK/Stat3信号通路活性的影响及其与鼻咽癌干性的关系，揭示EphA2增强鼻咽癌干性的分子机制；最后分析EphA2增强鼻咽癌干性与其促进鼻咽癌侵袭转移的关系。项目研究不仅可揭示EphA2增强鼻咽癌干性的作用及其机制以及与鼻咽癌转移的关系，而且能为靶向鼻咽癌干性以及鼻咽癌转移的防治提供潜在的靶点，具有重要的理论和实际意义。

我们前期采用蛋白质组学技术筛选鼻咽癌的关键致瘤蛋白质，发现EphA2能增强体外鼻咽癌细胞的干性；采用ELISA array筛选EphA2调控鼻咽癌细胞分泌的炎性细胞因子，发现EphA2诱导鼻咽癌细胞分泌IL6。为此，项目开展EphA2通过诱导IL6分泌增强鼻咽癌干性的作用及其机制研究。主要研究结果如下：(1)明确了高表达的EphA2增强鼻咽癌细胞的干性特征，并发现EphA2 S897位点磷酸化是EphA2增强鼻咽癌细胞干性必不可少的；(2)明确了EphA2通过诱导分泌IL6增加鼻咽癌细胞的干性特征；(3)发现EphA2通过激活NF-B信号诱导鼻咽癌细胞表达和分泌IL6，EphA2诱导分泌的IL6激活鼻咽癌细胞IL6R/JAK/Stat3信号通路； (4)明确了IL6激活的Stat3信号介导EphA2增加鼻咽癌细胞的体外侵袭和干细特征，发现EphA2诱导鼻咽癌细胞分泌的IL6及其激活的Stat3之间存在双向正反馈环路，导致Stat3组成性活化；(5) EphA2、IL6和p-Stat3的表达水平在有转移鼻咽癌组织高于无转移的鼻咽癌组织，而且三者的表达水平正相关，高表达EphA2的鼻咽癌患者预后不良。研究结果表明，EphA2是维持鼻咽癌干性的关键致瘤蛋白，EphA2通过诱导IL6自分泌，继而激活IL6R/JAK/Stat3信号通路增强鼻咽癌的干性特征，EphA2及其调控的IL6/IL6R/JAK/Stat3信号通路是潜在的鼻咽癌治疗靶点。通过项目研究，发表标注本项目资助的SCI论文7篇，获得国家发明专利1项，获得教育部自然科学奖二等奖1项，培养研究生3名。