Shimoyama Y, Nagafuchi A, Fujita S, Gotoh M, Takeichi M, Tsukita S, Hirohashi S
Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
Cancer Res. 1992 Oct 15;52(20):5770-4.
A human lung cancer cell line, PC 9, was analyzed to elucidate the molecular mechanisms of dysfunction of cadherin-mediated cell-cell adhesion in cancer. Although PC 9 cells strongly expressed E-cadherin at the cell membrane, which was indistinguishable immunochemically from functional E-cadherin, they did not show tight cell-cell adhesion and had reduced E-cadherin-mediated aggregation activity. Immunoprecipitation with E-cadherin and Western blot analysis revealed that PC 9 cells did not express alpha-catenin, a cadherin-associated protein, suggesting that this was the cause of the cadherin dysfunction in the cell line. In addition, Northern and Southern blot analyses disclosed homozygous deletion of part of the alpha-catenin gene, which might have resulted in the loss of alpha-catenin expression in PC 9 cells.
对人肺癌细胞系PC 9进行分析，以阐明癌症中钙黏蛋白介导的细胞间黏附功能障碍的分子机制。尽管PC 9细胞在细胞膜上强烈表达E-钙黏蛋白，其在免疫化学上与功能性E-钙黏蛋白无法区分，但它们并未表现出紧密的细胞间黏附，且E-钙黏蛋白介导的聚集活性降低。用E-钙黏蛋白进行免疫沉淀和蛋白质印迹分析表明，PC 9细胞不表达α-连环蛋白（一种与钙黏蛋白相关的蛋白质），这表明这是该细胞系中钙黏蛋白功能障碍的原因。此外，Northern和Southern印迹分析显示α-连环蛋白基因部分存在纯合缺失，这可能导致PC 9细胞中α-连环蛋白表达缺失。
