Analysis of hepatocarcinogenesis induced by hepatitis C virus-mediated host gene activation

1)采用反转录和聚合酶链反应相结合的竞争性检测方法，对HCV携带者血清样本进行检测。HCV的复制水平在晚期肝病中较高，病毒复制水平的升高可能在肝病的进展和肝癌发生中起重要作用。2)慢性肝病各阶段各基因型血清HCV RNA水平差异无统计学意义，基因型对肝病进展及肝癌发生影响不大。3)我们检测了HCC患者肝脏标本中HCV RNA负链的存在。在HCC和周围肝脏中检测到正链和负链RNA，表明HCV甚至在肿瘤细胞中复制。4) HCC中C-met mRNA及蛋白表达较周围正常肝脏升高。C-met蛋白表达与肿瘤分化不良有关。此外，在一些c-met阳性病例中观察到增殖活性升高。这些数据提示可能参与了c-met肝癌的发生。5)与周围正常肝脏相比，HCC中抑制多种情况诱导的细胞凋亡的Bcl-2癌蛋白表达升高，提示Bcl-2可能参与了HCC的发生发展。此外，Fas抗原的表达诱导细胞凋亡，在hcv感染的肝脏炎症中发挥了重要作用。6)利用蔗糖平衡密度梯度离心，我们发现HCV颗粒群由低密度病毒粒子和高密度免疫复合物和/或核衣壳组成，并且随着肝脏疾病的进展，特别是HCC的发展，HCV优势群体从免疫复合物和/或核衣壳上的病毒粒子转移。

1) Using a competitive assay that combined reverse transcription and polymerase chain reaction, we tested serum samples of HCV carriers. The replicative level of HCV is higher in advanced liver desease and the elevation of viral replication may play an important role in progression of liver disease and hepatocarcinogenesis.2) There was no significant difference in the serum HCV RNA levels among each genotype at every stage of chronic liver desease, and genotype seems to have little influence on the progression of liver disease and hepatocarcinogenesis.3) We examined the presence of the minus strand of HCV RNA in liver specimens of patients with HCC.The plus- and minus-strand RNA were detected in both HCC and surrounding liver, suggesting that HCV replicates even in tumor cells.4) C-met mRNA and protein expression were elevated in HCC compared in HCC compared with surrounding normal liver. C-met protein expression was related with poor defferentiation of the cancer. Moreover, elevated proliferative activity was observed in some c-met positive cases. These data suggest the possible involvement of c-met hepatocarcinogenesis.5) Expression of Bcl-2 oncoprotein, which inhibits apoptosis induced by a variety of circumstances, was elevated in HCC compared with surrounding normal liver, suggesting the possible involvement of Bcl-2 in the development of HCC.Also, expression of Fas antigen, which induces apoptosis, was supposed to play an important role of the inflammation in the HCV-infected liver.6) Using sucrose equilibrium density gradient centrifugation, we demonstrated that HCV particle populations consist of low-density virions and high-density immune complexes and/or nucleocapsids, and the dominant HCV populations shifted from virion on immune complex and/or nucleocapsid with progression of liver disease, especially the development of HCC.