Bureau Christophe, Péron J M, Bouisson Michèle, Danjoux Marie, Selves Janick, Bioulac-Sage Paulette, Balabaud Charles, Torrisani Jérome, Cordelier Pierre, Buscail Louis, Vinel Jean Pierre
INSERM U858, Fédération Digestive Purpan, CHU Toulouse, Toulouse, France.
J Gastroenterol Hepatol. 2008 Jan;23(1):78-86. doi: 10.1111/j.1440-1746.2007.05234.x.
Macronodules (MN) occurring in cirrhosis are considered to be precursor lesions for hepatocellular carcinoma (HCC). However, early molecular events in hepatocellular carcinogenesis are poorly understood. The aim of this study was to compare gene expression profiling between cirrhotic tissues, MN, and HCC, to identify genes early involved in liver carcinogenesis.
Tissues were obtained from explanted livers: nine cirrhosis, 10 MN, and seven HCC. Total RNAs were extracted by RNeasy and reverse transcribed with labelled [(33)P]-alpha ATP. Hybridations were performed on Atlas Human Cancer 1.2 membranes (1176 genes).
A two-way hierarchical clustering algorithm successfully isolated specific gene expression profiles when comparing MN, cirrhosis, and HCC. A total of 16 and 14 genes were up- and down-expressed, respectively, in HCC as compared to cirrhotic tissues. The molecular signature of MN was characterized by the down-expression of 23 and 42 genes as compared to cirrhosis and HCC, respectively. Among them, Klf6 was down-expressed in all MN samples whereas it was over-expressed in cirrhosis and HCC. This result was confirmed at RNA level by quantitative real time-polymerase chain reaction and at protein level by Western blotting. However, no mutation in the exon 2 of Klf6 was detected.
We identified a molecular signature of MN characterized by a down-expression of several genes. One of them, Klf6 was found to be down-expressed in all MN without evidence of somatic mutations in the exon 2. This gene could be involved at an early stage of hepatocarcinogenesis.
肝硬化中出现的大结节（MN）被认为是肝细胞癌（HCC）的前驱病变。然而，肝细胞癌发生过程中的早期分子事件尚不清楚。本研究的目的是比较肝硬化组织、MN和HCC之间的基因表达谱，以鉴定早期参与肝癌发生的基因。
从移植肝中获取组织：9例肝硬化、10例MN和7例HCC。用RNeasy提取总RNA，并用标记的[(33)P]-αATP进行逆转录。在Atlas Human Cancer 1.2膜（1176个基因）上进行杂交。
在比较MN、肝硬化和HCC时，双向层次聚类算法成功分离出特定的基因表达谱。与肝硬化组织相比，HCC中分别有16个和14个基因上调和下调表达。与肝硬化和HCC相比，MN的分子特征分别表现为23个和42个基因的下调表达。其中，Klf6在所有MN样本中均下调表达，而在肝硬化和HCC中则上调表达。通过定量实时聚合酶链反应在RNA水平以及通过蛋白质印迹在蛋白质水平证实了这一结果。然而，未检测到Klf6外显子2的突变。
我们鉴定了以几个基因下调表达为特征的MN分子特征。其中之一，Klf6被发现在所有MN中均下调表达，且外显子2无体细胞突变证据。该基因可能参与肝癌发生的早期阶段。
