幽门螺杆菌通过N-糖基化修饰促进胃癌耐药机制的研究

Intrinsic resistance is an important factor limiting the effects of chemotherapy for gastric cancer. Helicobacter pylori (H. Pylori) infection regulate gastric cancer cell sensitivity to chemotherapy drugs, and may be a potential factor for the intrinsic resistance of gastric cancer cells. Based on our previous study, we have found that infection-induced abnormal N-glycan modification, especially N-glycan modification of specific proteins play an important role for the generation of chemoresistance of cancer cells. In this project, with the use of lectin-microarray and mass spectrometry, we plan to systematically reveal the change of N-glycan modification induced by H. pylori infection in gastric cancer cells. The change of N-glycan modification will be evaluated in four aspects: identification and abundance of glycoproteins; characterization and occupancy of N-glycosites; major and site-specific glycoforms; expression profiles of glycotransferases. In addition, we will further investigate the role and related molecular mechanism of site-specific glycoforms of glycoproteins in regulating chemoresistance of gastric cancer cells. The study will not only provide the scientific basis for the selection of chemotherapy of gastric cancer; and also lay the foundation for the development of gastric cancer drug resistance markers and new gastric cancer therapeutic drugs.

先天性耐药是限制胃癌化疗效果的重要因素。幽门螺杆菌（H. pylori）感染能调控胃癌细胞对化疗药物的敏感性，可能是胃癌细胞获取先天耐药性的潜在因素。本课题在前期研究发现感染导致的N-糖基化修饰异常，尤其是特定蛋白N-糖基化修饰在肿瘤耐药形成中发挥重要作用的基础上，拟以凝集素芯片结合质谱检测技术，从糖基化蛋白种类和表达丰度、糖基化位点及其占有率、主要糖型及位点特异性糖型、糖基转移酶表达谱这四个方面系统性解析H. pylori感染导致的胃癌细胞N-糖基化修饰异常，并探究特定蛋白糖基化位点修饰异常在介导化疗耐受中的作用及其分子机制。该研究不仅有助于为胃癌化疗药物的合理选择提供科学依据；而且可为进一步研发胃癌耐药标志物和新型胃癌治疗药物奠定基础。

术后化疗是绝大多数胃癌患者治疗主要手段，而肿瘤细胞耐药的出现是影响患者生存时间和生存质量中最亟待解决的问题。H. pylori 感染引起的胃癌细胞 N-糖基化修饰异常在肿瘤耐药中的作用有助于进一步深入解析胃癌耐药产生的分子机制并为胃癌化疗药物的合理选择，提高胃癌治疗效果提供科学依据。本研究利用凝集素芯片结合质谱检测技术，筛选出糖基化修饰异常蛋白及对应糖基转移酶，进一步实验验证其在胃癌进展及耐药方面发挥的作用。研究成果显示：1、H. pylori通过上调FUT8促进蛋白岩藻糖修饰提高胃癌细胞先天性耐药；2、PRTG在HP感染的胃癌组织中表达上调，且HP通过诱导PRTG表达促进胃癌细胞的增殖、侵袭和转移并介导胃癌细胞的耐药；3、H.Pylori可通过上调HOXC10促进胃癌细胞增殖、侵袭和迁移，并抑制S期阻滞导致胃癌细胞顺铂耐药；4、H.pylori上调胃癌细胞糖基转移酶B4GALT5的表达，且B4GALT5可以促进胃癌细胞的增殖、侵袭和迁移。本项目的研究成果为胃癌进展及临床治疗提供了新的靶点和研究思路。