A study to explore the mechanism of hepatic metastasis of colon cancer through Heregulin

我们探讨了肝细胞在结直肠癌肝转移过程中表达HERG的机制。对人肝转移瘤标本进行免疫组织化学(IHC)检测，HRG在肝细胞中的阳性表达率为88.7%。在靠近转移瘤的肝细胞中有明显表达，而在与肿瘤接触、损伤的肝细胞和远区的肝细胞中无表达。二甲基亚硝胺(DMN)可引起大鼠肝细胞HRG mRNA表达从第1天起显著高于对照组。免疫组织化学检查显示，肝细胞在DMN损伤后1d左右肝细胞开始表达HRG，但在肝小叶中央带未见表达。肝部分切除后，残肝内肝细胞表达HRG。这些结果表明，在肝脏损伤和再生阶段，残留肝细胞中存在HRG的表达。

We investigated a mechanism why hepatocytes express Heregulin(HRG) in the situation of hepatic metastasis of colorectal cancer. Immunohistochemical(IHC) examination on human specimen of hepatic metastasis revealed that HRG was expressed in hepatocytes at 88.7 %. The expression was evident in hepatocytes which were close to the metastatic tumor but not in those which were contact to the tumor with being injured nor in far region. Dimethylnitrosoamine(DMN) caused significantly increased expression of HRG mRNA in rat hepatocytes from day 1 compared with that of the control. IHC examination revealed that HRG expression in hepatocytes started from day 1 around the area of Glisson's capsule but not in the area of central zone of hepatic lobules where were injured by DMN. Partial hepatectomy also revealed that hepatocytes in the residual liver expressed HRG. These results suggest that HRG expression is appeared in the residual hepatocytes in the stage of injury and regeneration of the liver.