Yonezawa S, Byrd J C, Dahiya R, Ho J J, Gum J R, Griffiths B, Swallow D M, Kim Y S
Gastrointestinal Research Laboratory, VA Medical Center, San Francisco, CA.
Biochem J. 1991 Jun 15;276 ( Pt 3)(Pt 3):599-605. doi: 10.1042/bj2760599.
The purpose of this study was to determine the quantity and nature of the mucins synthesized and secreted by four different pancreatic cancer cell lines. Well- to moderately-differentiated SW1990 and CAPAN-2 human pancreatic cancer cells were found to produce more high-Mr glycoprotein (HMG) than less-differentiated MIA PaCa-2 and PANC-1 cells. Most of the labelled HMG was secreted within 24 h. The results of chemical and enzymic degradation, ion-exchange chromatography and density-gradient centrifugation indicated that the HMG in SW1990 and CAPAN-2 cells has the properties expected for mucins, whereas much of the HMG in MIA PaCa-2 and PANC-1 cells may not be mucin, but proteoglycan. These results are consistent with immunoblots and Northern blots showing the presence of apomucin and apomucin mRNA in SW1990 and CAPAN-2 cells, but not in MIA PaCa-2 and PANC-1 cells. The Western blots and Northern blots also show that SW1990 and CAPAN-2 cells, like breast cancer cells, have the mammary-type apomucin and mRNA coded by the MUC1 gene, but lack the intestinal type apomucin and mRNA coded by the MUC2 gene. In contrast, the colon cancer cell lines tested in culture express apomucin and mRNA coded by MUC2 but not by MUC1.
本研究的目的是确定四种不同胰腺癌细胞系合成与分泌的黏蛋白的数量和性质。结果发现，高分化至中分化的SW1990和CAPAN-2人胰腺癌细胞产生的高分子量糖蛋白（HMG）比低分化的MIA PaCa-2和PANC-1细胞更多。大多数标记的HMG在24小时内被分泌。化学和酶降解、离子交换色谱和密度梯度离心的结果表明，SW1990和CAPAN-2细胞中的HMG具有黏蛋白预期的特性，而MIA PaCa-2和PANC-1细胞中的许多HMG可能不是黏蛋白，而是蛋白聚糖。这些结果与免疫印迹和Northern印迹一致，后者显示SW1990和CAPAN-2细胞中存在脱辅基黏蛋白和脱辅基黏蛋白mRNA，而MIA PaCa-2和PANC-1细胞中则没有。Western印迹和Northern印迹还表明，SW1990和CAPAN-2细胞与乳腺癌细胞一样，具有由MUC1基因编码的乳腺型脱辅基黏蛋白和mRNA，但缺乏由MUC2基因编码的肠型脱辅基黏蛋白和mRNA。相比之下，培养中测试的结肠癌细胞系表达由MUC2而非MUC1编码的脱辅基黏蛋白和mRNA。
