肝癌预防性疫苗设计及机制研究

The development and progression of cancer (e.g.liver cancer) usually undergoes a long-time and multi-step process including transformation of normal cells to pre-cancer cells and subsequent cancer cells. We speculate that the long window period for liver cancer development will allow immune intervening strategies to promote adaptive mechanisms towards an enhanced immunosurveillance, which could effectively eradicate or at least control the few pre-cancerous cells undergoing neoplastic transformation during early pre-malignant stages in cancer development, and protect the host from lethal tumor formation. We previously showed that placenta gp96 associates multiple embryonic antigens and induce proventive and therapeutic immunoresponses against liver cancer both in mice models and clinical trial. In this study, we will explore the molecular basis of placenta gp96 induced HCC protective immunity by analyzing the gp96 associated carcinoembryonic antigen using comprehansive methods. The appropriate prophylactic antigens against liver cancer will be defined by profiling gene and protein expression patterns in HCC development. We will explore adaptive mechanisms toward an enhanced immune surveillance which could effectively eradicate or at least control early premalignant stages in liver cancer development. Recombinant gp96-based prophylactic liver cancer vaccine will be thereby designed. Given limited drugs and vaccines available against liver cancer, this study will provide the pre-clinical feasibility and mechanistic basis to initiate clinical vaccine trials to prevent or reduce HCC occurrence.

包括肝癌在内的多种肿瘤的发生与发展通常经历一个长时间的由正常细胞向癌前细胞、癌细胞转化的多步骤过程，通过免疫干预手段激活获得性免疫增强机体的免疫监视能力，能够有效的清除或至少控制癌前恶性转化的细胞，保护机体免受肝癌等恶性肿瘤的危害。我们前期研究发现胎盘来源的热休克蛋白gp96携带多种癌胚抗原,通过小鼠试验和临床试验证实对肝癌等肿瘤有显著的免疫预防和治疗效果。本研究拟通过多种方法鉴定对肝癌有预防作用的癌胚抗原，结合肝癌发生过程中基因表达谱和蛋白表达谱分析发现阻断肝癌发生的潜在抗原靶点，深入探索抗原特异性T细胞在清除早期肝癌癌前病变和肿瘤休眠细胞的免疫监视中所发挥的作用机制，在此基础上设计以重组gp96为佐剂的肝癌预防性疫苗并验证免疫学功能。鉴于目前肝癌的防治药物和手段都十分有限，本研究将为阻断慢性乙肝、肝硬化患者向肝癌转化提供新的思路。

本项目研究发现人胎盘gp96鉴定出有效结合蛋白514条多肽肽库，归类于142个蛋白中，揭示了胎盘gp96-癌胚抗原复合物防治肝癌的分子作用机制。验证APOE、Trim28、NUP188以及GPC3、PEG10等多种癌胚抗原具有抗肝癌等肿瘤的免疫学功能，体外将重组gp96与抗原多肽结合，通过小鼠实验验证对DEN诱导的HCC有明显预防效果，显示设计的肝癌预防性疫苗抗肿瘤的免疫学功能。建立了胎盘gp96体外活化DC的方法，胎盘gp96活化DC免疫治疗肝癌、肺癌等肿瘤技术已经获得佛山中医院伦理委员会批准，正准备开展临床试验。相关研究成果在Molecular Cancer、Journal of Virology、PLoS ONE等杂志发表论文10篇，获得国家发明专利授权2项。