Rogacki Karol, Kasprzak Aldona, Stępiński Adrian
Aldona Kasprzak, Department of Histology and Embryology, Poznan University of Medical Sciences, Święcickiego 6, 60-781 Poznan, Poland, e-mail:
Pol J Pathol. 2015 Mar;66(1):9-21. doi: 10.5114/pjp.2015.51148.
The Wnt/Fzd/β-catenin signaling pathway plays a significant role in physiology and pathology of the liver. The role of β-catenin is linked mainly to the canonical pathway of the system. Phosphorylation of β-catenin and abnormalities in function of the E-cadherin-catenin unit lead to loss of intercellular junctions, progression in liver fibrosis, and development of cirrhosis and hepatocellular carcinoma (HCC). Progression of liver diseases is noted to be accompanied by disturbances in β-catenin expression (mainly with its overexpression), with its cytoplasmic or nuclear translocation and with lowered expression of E-cadherin. Increase in transcriptional activity of β-catenin is associated mainly with mutations of CTNNB1. Detailed mechanisms of HCC development are not known. More β-catenin mutations are manifested in hepatitis C virus (HCV)-associated than in HBV-related HCC. In recent years the role of nonstructural proteins and of the core protein of HCV has been accentuated in induction of the Wnt pathway. HCV proteins affect in a double manner expression of E-cadherin, including modulation of the Wnt pathway and reduction of E-cadherin expression at the transcriptional level. This review presents current data on mechanisms of hepatocarcinogenesis involving participation of the Wnt canonical pathway and, in particular, interaction of Wnt pathway components with HCV genome products in the process.
Wnt/Fzd/β-连环蛋白信号通路在肝脏的生理和病理过程中发挥着重要作用。β-连环蛋白的作用主要与该系统的经典途径相关。β-连环蛋白的磷酸化以及E-钙黏蛋白-连环蛋白单元功能异常会导致细胞间连接丧失、肝纤维化进展、肝硬化和肝细胞癌(HCC)的发生。肝脏疾病的进展伴随着β-连环蛋白表达紊乱(主要是其过表达)、其在细胞质或细胞核中的易位以及E-钙黏蛋白表达降低。β-连环蛋白转录活性增加主要与CTNNB1突变有关。HCC发生的详细机制尚不清楚。与乙型肝炎病毒(HBV)相关的HCC相比,丙型肝炎病毒(HCV)相关的HCC中β-连环蛋白突变更为明显。近年来,HCV的非结构蛋白和核心蛋白在诱导Wnt途径中的作用得到了强化。HCV蛋白以双重方式影响E-钙黏蛋白的表达,包括调节Wnt途径以及在转录水平降低E-钙黏蛋白的表达。本综述介绍了有关涉及Wnt经典途径参与的肝癌发生机制的当前数据,特别是在该过程中Wnt途径成分与HCV基因组产物的相互作用。