Miura S, Kim Y S
Int J Cancer. 1986 Aug 15;38(2):197-205. doi: 10.1002/ijc.2910380209.
The effect of the glycosylation inhibitor, tunicamycin, on synthesis and secretion of the membrane-associated glycoprotein carcinoembryonic antigen (CEA), was studied in the LS174T human colon cancer cell line. Tunicamycin treatment inhibited total cellular glycoprotein synthesis but did not affect CEA levels of cellular homogenate, membrane or cytosol fractions as determined by enzyme immunoassay. Control cells metabolically labelled with 3H-glucosamine, 3H-leucine or 35S-cysteine exhibited membranous and extracellular (i.e. secreted) CEA with an MW of 200 kDa as judged by SDS-gel electrophoresis following immunoprecipitation. However, in the tunicamycin-treated cells several forms of CEA with lower MWs and representing molecules with decreased glycosylation could be detected in addition to the original CEA molecule of 200 kDa present in control cells. The rates of synthesis, secretion and turnover of the lower-molecular-weight forms of poorly glycosylated CEA that appear after tunicamycin treatment are similar to those of CEA in control cells. These data suggest that the carbohydrate portion of the CEA molecule is not essential in synthesis, incorporation into the membrane, and secretion of CEA by colon cancer cells in vitro.
在LS174T人结肠癌细胞系中研究了糖基化抑制剂衣霉素对膜相关糖蛋白癌胚抗原（CEA）合成和分泌的影响。衣霉素处理抑制了细胞总糖蛋白合成，但通过酶免疫测定法测定，并未影响细胞匀浆、膜或胞质溶胶组分中的CEA水平。用³H - 葡糖胺、³H - 亮氨酸或³⁵S - 半胱氨酸进行代谢标记的对照细胞，经免疫沉淀后通过SDS - 凝胶电泳判断，显示出分子量为200 kDa的膜性和细胞外（即分泌型）CEA。然而，在衣霉素处理的细胞中，除了对照细胞中存在的200 kDa原始CEA分子外，还可检测到几种分子量较低且糖基化程度降低的CEA形式。衣霉素处理后出现的糖基化程度低的低分子量CEA形式的合成、分泌和周转速率与对照细胞中CEA的相似。这些数据表明，在体外，CEA分子的碳水化合物部分对于结肠癌细胞合成、整合到膜中以及分泌CEA并非必不可少。
