Nuruki K, Toyoyama H, Ueno S, Hamanoue M, Tanabe G, Aikou T, Ozawa M
Departments of Biochemistry and Surgery, Faculty of Medicine, Kagoshima University, Kagoshima 890-8520, Japan.
Oncol Rep. 1998 Sep-Oct;5(5):1109-14. doi: 10.3892/or.5.5.1109.
Cadherins are Ca2+-dependent cell-cell adhesion molecules, and are involved in the formation and maintenance of the histo-architecture. Using a combination of biochemical and immunohistochemical methods, we analyzed the expression of the cadherin-catenin complex in 34 human hepatocellular carcinomas. Unexpectedly, we found the expression of N (neural)-cadherin in normal hepatocytes and all hepatocellular carcinomas examined. In 18 cases, the decreased expression of E (epithelial)-cadherin was observed. Among them, the decreased expression of alpha-catenin and gamma-catenin (plakoglobin) was also observed in 9 and 6 cases, respectively. Thus the decreased expression of alpha-catenin and gamma-catenin was apparently preceded by the decreased expression of E-cadherin. The decreased expression of beta-catenin was not observed in any of the cases analyzed. beta-Catenin was found to accumulate in the cytoplasm of hepatocellular carcinomas with the decreased expression of E-cadherin, despite the presence of N-cadherin at the cell-cell contacts. These results suggest a pivotal role of E-cadherin in the intracellular distribution of catenins in hepatocellular carcinomas.
钙黏蛋白是依赖钙离子的细胞间黏附分子，参与组织结构的形成与维持。我们运用生化和免疫组织化学方法相结合，分析了34例人类肝细胞癌中钙黏蛋白-连环蛋白复合体的表达情况。出乎意料的是，我们在正常肝细胞以及所有检测的肝细胞癌中均发现了N（神经）-钙黏蛋白的表达。在18例病例中，观察到E（上皮）-钙黏蛋白表达下降。其中，分别有9例和6例还观察到α-连环蛋白和γ-连环蛋白（桥粒斑蛋白）表达下降。因此，α-连环蛋白和γ-连环蛋白表达下降显然先于E-钙黏蛋白表达下降。在所分析的任何病例中均未观察到β-连环蛋白表达下降。尽管在细胞间接触部位存在N-钙黏蛋白，但在E-钙黏蛋白表达下降的肝细胞癌细胞质中发现β-连环蛋白积聚。这些结果表明E-钙黏蛋白在肝细胞癌连环蛋白的细胞内分布中起关键作用。
