生物质谱发掘肝癌中蛋白可变剪切标志物研究

Hepatocellular carcinoma (HCC) is the fifth common and third fatal cancer in the world. In china, the proportion of both new cases and deaths suffering from liver cancer is about 50% of global patients. Recently, there are more and more proofs suggesting protein isoforms produced by alternative splicing are closely related to carcinoma, especially in HCC. Consequently, the isoforms may become valuable biomarker for diagnose because of their specificity in expression. However, the traditional research based on single gene or screening cannot discover isoforms in a large scale, which ignore lots of isoforms involving in disease. Fortunately, multiple reaction monitoring (MRM), a new technology of mass spectrometry, makes high-through screening and validation of isoforms into reality. Combining proteomic tools with clinical verification, we could discover isoforms correlated to HCC, which may suggest new biomarkers for liver cancer.

原发性肝细胞癌（HCC）在世界范围内是第五位最常见和第三位致死率最高的恶性肿瘤，在我国每年肝癌新发和死亡病例均占全球一半以上。随着研究的深入，愈来越多的证据显示由可变剪切形成的蛋白质异构体在包括HCC在内的多种肿瘤形成中有着密切的联系，且由于其表达的特异性，具有着成为新一代诊断标志物的重要的价值。但基于单基因或简单筛选的传统研究模式无法对其进行规模化的分析，造成许多参与HCC发病过程中的异构体被忽视。另一方面，已有的筛选策略主要集中于转录水平，缺乏蛋白质水平上的证据，因此对标志物筛选和应用而言缺少了蛋白质验证这重要的一环。新兴的质谱策略- - -多反应离子监控（Multiple Reaction Monitoring，MRM）技术，为高通量的筛选和验证可变剪切体提供了现实基础。立足于本实验的蛋白质组平台，结合质谱数据解析和验证，我们可以从蛋白多样性角度筛选相关的异构体作为临床指标，从而提高诊断

肝细胞癌（HCC）在世界范围内是第五位最常见和第三位致死率最高的恶性肿瘤。有关可变剪接对肝细胞癌的影响研究鲜有报道。在本研究中，我们首先通过理论的外显子拼接，构建了目前最全面的剪接序列数据库。然后，采用基于细胞培养氨基酸稳定同位素标记（SILAC）的蛋白质组学方法，我们在HCC97L和LM6肝癌高、低转移细胞株中，共鉴定157个显著差异表达的剪接亚型。与HCC转移功能密切相关的候选标志物中，我们验证了三个剪接基因CEACAM1, ISOC2 和VPS29，其不同的剪接亚型在肝癌肿瘤和正常组织中表达差异显著，进一步表明可变剪接亚型能够成为肝癌新的分子标志物。