肝癌门静脉癌栓相关小分子的比较蛋白质组学分析

Comparative proteome analysis of PVTT related small molecules

目的筛选肝细胞肝癌门静脉癌栓（PVTT）形成过程中起重要作用的低相对分子质量蛋白质标记物。方法选取肝癌门静脉癌栓和肝癌无癌栓患者原发瘤组织各12例，利用16％SDS—PAGE和Tris-Tricine系统进行双向电泳，得到小相对分子质量蛋白表达图谱，经Image Master软件对比分析后，基质辅助激光解析飞行时间质谱（MALDI—TOFMS／MS）对差异点进行鉴定。免疫印迹法对鉴定蛋白进行初步验证。结果无PVTT和PVTT的原发瘤组织间共检测到88个差异点，其中相对分子质量（MW）低于20×10^3的差异点有42个。与无PVTT组比较，PVTT组中有41个蛋白点表达上调（其中19个MW低于20×10^3），47个蛋白点表达下调（23个MW低于20×10^3）。经质谱鉴定共发现钙结合蛋白S100A11，脂肪酸结合蛋白-1等11种胶内差异小分子蛋白质。免疫印迹验证结果证实S100A11在有或无PVTT的原发瘤组织中的确存在表达差异。结论PVTT的原发瘤组织与无PVTT原发瘤组织中存在差异表达的低相对分子质量蛋白，推测肝癌侵袭转移性与多种差异蛋白相关，S100A11可能是其中一种。

Objective To screen low molecular weight protein biomarkers which played an important role during the course of portal vein tumor thrombi （PVTT） formation in hepatocellular carcinoma （HCC）. Methods We first selected 2 groups （ each group had 12 cases） of primary tumor tissue from human HCC with or without PVTF. Then a stable and standard low MW （ 〈20 ×10^3） protein electrophoresis platform was sued by changing both SDS-PAGE gel concentration and components of electrophoretic buffer system in the second step of 2-DE. Using optimized 2-DE and MALDI-TOF MS/MS, differentially expressed proteomes were compared and studied in the 2 groups. By using Western blot, the results were i- dentified. Results Protein samples from PVTT group or non-PVTF group ran 2-DE for 3 times repeatedly under the same conditions. Eighty-eight differential spots were detected between primary tumor tissues of the two groups. Compared with non-PVTT group, there were 41 up-regulated spots （including 19 MW lower than 20 × 10^3 ） and 47 down-regulated spots in PVTT group （ including 23 MW lower than 20×10^3 ）. Thirty-six spots were picked and redundancy was eliminated. Finally, I 1 significantly differential low MW proteins such as S100All and fat acid binding （FAB） protein etc were further identified by MALDI-TOF MS/MS. The results from Western blotting validation confirmed the differential expression of S100A11 in primary tumor tissue with PVTT or without PVTT. Conclusion The low MW protein profile of HCC primary tumor tissue with PVTT displayed obvious difference compared with HCC tissue without PVTT. The results indicated that the invasive and metastatic characteristic of HCC had relations with many differentially expressed proteins, including S100A11.