Asselah Tarik, Bièche Ivan, Laurendeau Ingrid, Paradis Valérie, Vidaud Dominique, Degott Claude, Martinot Michelle, Bedossa Pierre, Valla Dominique, Vidaud Michel, Marcellin Patrick
Service d'Hépatologie and INSERM CRB3, AP-HP Hôpital Beaujon, University of Paris VII, Paris, France.
Gastroenterology. 2005 Dec;129(6):2064-75. doi: 10.1053/j.gastro.2005.09.010.
BACKGROUND & AIMS: The molecular mechanisms of hepatocellular carcinoma have been studied, but little is known of the changes in liver gene expression during the different stages of chronic hepatitis C virus (HCV) infection, in particular the transition from mild to moderate fibrosis.
We used real-time quantitative RT PCR to study the messenger RNA expression of 240 selected genes in 2 pools of liver specimens according to the stages of fibrosis (Metavir score; mild fibrosis = F1 and septal fibrosis = F2). Genes whose expression differed between pools (F2 vs F1) by at least 2-fold were selected. In addition, the expression level of these selected genes then was assessed in each of the 62 individual samples (F4, n = 6; F3, n = 17; F2, n = 21; vs F1, n = 18).
The 22 genes that were up-regulated in the 21 F2 samples relative to the 18 F1 samples mainly encoded genes involved in cytoskeleton (KRT 19 and SCG 10), growth factors/cytokines (CXCL6, interleukin 8 [IL8], IL1A, IL2, and CXCL10), or growth factor receptors (CCR2, CXCR3, and CXCR4), or were involved in extracellular matrix production (COL1A1, CHI3L, and SPP1), in extracellular matrix remodeling (TIMP1, MMP7, and MMP9), and in cell junction (ITGA2 and CLDN 4). When hierarchically clustering the F2 and F1 samples according to the expression of the 11 most discriminatory genes (KRT 19, COL1A1, STMN2, CXCL6, CCR2, TIMP1, IL8, IL1A, ITGA2, CLDN 4, and IL2), the patient population was categorized into 2 subgroups: F1 and F2. Specifically, 15 of 18 F1 (83%) and 19 of 21 F2 (90%) were classified correctly (P < 10(-5)). We also studied the messenger RNA expression of these 240 selected genes in normal liver in comparison with F1. Genes dysregulated in the transition from normal liver to F1 mainly were interferon-inducible genes, and therefore were very different from those dysregulated in the transition from F1 to F2.
Genes involved in extracellular matrix turnover and immune response are implicated in the transition from mild to moderate fibrosis. Eleven of the genes could form the basis for the gene expression signature of mild versus moderate fibrosis in patients with chronic hepatitis C.
肝细胞癌的分子机制已得到研究，但对于慢性丙型肝炎病毒（HCV）感染不同阶段肝脏基因表达的变化，尤其是从轻度纤维化到中度纤维化的转变过程，我们了解甚少。
我们运用实时定量逆转录聚合酶链反应（RT-PCR），根据纤维化阶段（梅塔维分级；轻度纤维化=F1，间隔纤维化=F2），研究了2组肝脏标本中240个选定基因的信使核糖核酸（mRNA）表达。选择那些在两组标本（F2与F1）之间表达差异至少达2倍的基因。此外，随后在62个个体样本（F4，n=6；F3，n=17；F2，n=21；与F1，n=18）中评估这些选定基因的表达水平。
相对于18个F1样本，21个F2样本中上调的22个基因主要编码参与细胞骨架（角蛋白19和神经元生长抑制蛋白10）、生长因子/细胞因子（CXC趋化因子配体6、白细胞介素8 [IL8]、白细胞介素1A、白细胞介素2和CXC趋化因子配体10）、生长因子受体（C-C趋化因子受体2、CXC趋化因子受体3和CXC趋化因子受体4）的基因，或参与细胞外基质产生（I型胶原蛋白α1链、几丁质酶3样蛋白1和分泌性磷蛋白1）、细胞外基质重塑（金属蛋白酶组织抑制因子1、基质金属蛋白酶7和基质金属蛋白酶9）以及细胞连接（整合素α2和紧密连接蛋白4）的基因。根据11个最具鉴别力的基因（角蛋白19、I型胶原蛋白α1链、微管相关蛋白2、CXC趋化因子配体6、C-C趋化因子受体2、金属蛋白酶组织抑制因子1、白细胞介素8、白细胞介素1A、整合素α2、紧密连接蛋白4和白细胞介素2）的表达对F2和F1样本进行分层聚类时，患者群体被分为2个亚组：F1和F2。具体而言，18个F1样本中的15个（83%）和21个F2样本中的19个（90%）被正确分类（P<10⁻⁵）。我们还将这240个选定基因在正常肝脏中的mRNA表达与F1样本进行了比较。从正常肝脏到F1转变过程中失调的基因主要是干扰素诱导基因，因此与从F1到F2转变过程中失调的基因有很大不同。
参与细胞外基质周转和免疫反应的基因与从轻度纤维化到中度纤维化的转变有关。其中11个基因可为慢性丙型肝炎患者轻度与中度纤维化的基因表达特征奠定基础。
