葡萄糖调节蛋白78调控乙型肝炎相关性肝细胞癌患者线粒体生成蛋白的表达及临床分析

Glucose-regulated protein 78 regulates the expression of mitochondrial genesis proteins in HBV-related hepatocellular carcinoma: a clinical analysis

目的研究葡萄糖调节蛋白78(GRP78)在乙型肝炎相关性肝细胞癌组织中的表达及其与患者临床病理特征的关系,探索GRP78对肝癌细胞中线粒体生成相关蛋白分子的调控,为建立肝癌防治的新策略提供基础。方法收集乙型肝炎相关性肝细胞癌54例患者组织标本,用免疫组化和Western Blot检测肝癌及癌旁组织中GRP78、Lon、TFAM、COXⅣ的表达;用siRNA干涉肝癌细胞中GRP78的表达,检测细胞中GRP78、Lon、TFAM、COXⅣ的表达;用实时定量PCR(qRT-PCR)检测临床标本和干涉GRP78表达后肝癌细胞中线粒体DNA(mt DNA)的水平;对临床资料和实验数据进行统计分析。计量资料2组间比较比较采用t检验,计数资料2组间比较采用Fisher精确检验,患者生存分析采用Kaplan-Meier法。结果 GRP78及Lon在乙型肝炎相关性肝癌组织中的表达显著高于癌旁组织(t值分别为9.135、5.523,P值均<0.001),而线粒体生成相关蛋白TFAM、COXⅣ的表达及mt DNA水平显著低于癌旁组织(t值分别为2.765、4.260、12.280,P值分别为0.011、<0.001、<0.001)。干涉肝癌细胞中GRP78的表达,可显著提高线粒体生成相关蛋白TFAM、COXⅣ的表达及mt DNA水平(P值均<0.05)。GRP78在不同肿瘤数量、门静脉癌栓以及肿瘤分期的病例中,表达水平存在显著差异(P值分别为0.016、0.003、0.045);GRP78低表达患者术后总生存期及无复发生存期优于GRP78高表达的患者(χ2值分别为5.006、4.995,P值分别为0.025、0.026)。结论 GRP78对线粒体维持与生成具有潜在的调控作用,对建立潜在的肝癌防治新策略具有重要的临床指导意义。

Objective To investigate the expression of glucose-regulated protein 78（ GRP78） in HBV-related hepatocellular carcinoma（ HBV-HCC） and its association with clinicopathological features,as well as its regulatory effect on mitochondrial genesis proteins in hepatoma cells,and to provide a basis for new strategies for the prevention and treatment of HCC. Methods Tissue samples were collected from54 patients with HBV-HCC,and immunohistochemistry and Western blot were used to measure the expression of GRP78,Lon,TFAM,and cytochrome C oxidase Ⅳ（ COX Ⅳ）. The expression of GRP78 in hepatoma cells was interfered by siRNA,and then the expression of GRP78,Lon,mitochondrial transcription factor A（ TFAM）,and COX Ⅳ was measured. Quantitative real-time PCR was used to measure the level of mitochondrial DNA（ mt DNA） in clinical specimens and HCC cells after GRP78 expression was interfered with. A statistical analysis was performed for clinical and experimental data. The t-test was used for comparison of continuous data between groups,the Fisher＇s exact test was used for comparison of categorical data between groups,and the Kaplan-Meier method was used for survival analysis. Results Compared with the adjacent tissues,HBV-HCC tissues had significantly higher expression of GRP78 and Lon（ t = 9. 135 and 5. 523,both P 0. 0001） and significantly lower expression of the mitochondrial genesis proteins TFAM and COX Ⅳ and mt DNA level（ t = 2. 765,4. 260,and 12. 280,P = 0. 011, 0. 001,and 0. 001）. There were significant increases in the expression of the mitochondrial genesis proteins TFAM and COX Ⅳ and mt DNA level after the interference with GRP78 expression in hepatoma cells（ all P 0. 05）. There were significant differences in the expression of GRP78 between patients with different numbers of tumors,patients with and without portal vein tumor thrombus,and patients with different tumor stages（ P = 0. 016,0. 003,and 0. 045）. The patients with low GRP78 expression had significantly longer overall survival and recurrence-free survival after surgery than those with high GRP78 expression（ χ2= 5. 006 and4. 995,P = 0. 025 and 0. 026）. Conclusion GRP78 has a potential regulatory effect on mitochondrial genesis and maintenance and has important clinical guiding significance in establishing new strategies for the prevention and treatment of HCC.