PDIA4/RPN1复合体促RAD18介导的DNA损伤修复与胶质瘤替莫唑胺化疗抵抗及机制研究

恶性胶质瘤是中枢神经系统最常见的恶性肿瘤，替莫唑胺（TMZ）是其一线化疗药物，深入探讨其化疗抵抗机制具有重要的理论价值和临床意义。在青年基金资助下，前期研究发现胶质瘤组织中PDIA4表达显著升高且与患者的不良预后有关，干扰PDIA4表达可抑制胶质瘤细胞增殖、引起G1/S期阻滞，下调RAD18的蛋白表达水平，增强TMZ的化疗效果，并发现PDIA4能够与RPN1蛋白相互结合，RNA-seq和蛋白定量质谱分析显示其下游主要为DNA损伤修复通路。我们拟通过临床研究、细胞、动物及类器官实验，明确PDIA4、RPN1和RAD18对胶质瘤患者TMZ敏感性和预后的影响，研究PDIA4和RPN1的相互作用及具体结合区域，查明PDIA4/RPN1复合体是否通过抑制RAD18的降解进而促进DNA损伤修复而参与胶质瘤细胞TMZ耐药。项目旨在为寻找胶质瘤治疗新靶点和为基于新靶点的胶质瘤个体化治疗奠定理论基础。

Gliomas have been the most common malignant tumor in the central nervous system, with Temozolomide recognized as the first-line drug for chemotherapy. It is theoretically and practically significant to investigate the mechanisms involved in the chemotherapy resistance of gliomas. With the support of the Youth Program of National Natural Science Foundation of China, our group found that PDIA4 was significantly increased in gliomas and was related to the poor prognosis of the patient in previous researches. Interfering with PDIA4 expression can inhibit the proliferation of glioma cells, cause the block of G1 / S phase, down-regulate the protein expression level of RAD18, and increases the chemotherapy effect of TMZ. We further found that PDIA4 can bind to RPN1 protein. RNA-seq and protein quantitative mass spectrometry analysis revealed that the downstream pathway of PDIA4 was mainly DNA damage repair. We plan to determine the effects of PDIA4, RPN1 and RAD18 on TMZ sensitivity and prognosis of glioma patients through cellular, animal, organoid, and clinical experiments. We also would investigate the interaction between PDIA4 and RPN1, reveal their specific binding area, and confirm whether the PDIA4 / RPN1 complex is responsible for TMZ resistance in gliomas cell through inhibiting the degradation of RAD18 to promote DNA damage repair. This project is the in-depth and subsequent study of the long-term research, which lays a theoretical foundation for finding new targets with regard to the treatment of gliomas and the corresponding individualized treatment of gliomas patients based on these new targets.