Cell-to-cell heterogeneity in the expression of carbohydrate-based epitopes of a mucin-type glycoprotein on the surface of human mammary carcinoma cells.
Cell-to-cell heterogeneity in the expression of carbohydrate-based epitopes of a mucin-type glycoprotein on the surface of human mammary carcinoma cells.
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人乳腺癌细胞表面粘蛋白型糖蛋白的碳水化合物表位表达的细胞间异质性。
DOI：
10.1002/jcp.1041370215
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发表时间：
1988
影响因子：
5.6
通讯作者：
Parry,G
中科院分区：
文献类型：
--
作者：
Moss,L;Greenwalt,D;Cullen,B;Dinh,N;Ranken,R;Parry,G
PAS-O是一种大的、O-连接的糖蛋白，是正常乳腺上皮表面的主要分化抗原，也存在于许多乳腺肿瘤和乳腺癌细胞系的表面。表达PAS-O的肿瘤细胞群体的一个特征是细胞间的异质性与分子的存在或不存在有关。在这项研究中，我们使用人乳腺癌细胞系734B和一组6个与PAS-O反应的单抗来研究这种异质性的基础。对乳脂球膜和脱脂牛奶中与PAS-O结合的抗体进行了广泛的Western印迹分析，结果表明，这些抗体都识别PAS-O的不同表位，并且这些表位被高碘酸氧化破坏，证明了它们的寡糖基础。6株单抗对734B细胞均呈异质性染色。此外，来自亲本734B群体的5个克隆在每个表位的表达上也表现出异质性。对734B克隆的染色分析表明，在某些情况下，克隆群体中的某些细胞与一种单抗染色，而不与另一种抗体染色。然而，值得注意的是，当在抗体染色之前用神经氨酸酶处理734B细胞时，大多数异质性被消除，除了一种外，所有的单抗都染色了90%-100%的细胞。细胞染色的增加与蛋白质印迹上PAS-O染色的增加相匹配。我们得出结论，734B细胞上PAS-O表达的异质性部分是由于唾液酸掩盖了表位，以及PAS-O唾液酸化程度的变化(在细胞间的基础上)。
A large, O‐linked glycoprotein, termed PAS‐O, is a major differentiation antigen on the surface of normal lactating breast epithelia and is also found on the surface of many mammary tumors and mammary carcinoma cell lines. A characteristic feature of populations of tumor cells that express PAS‐O is thecell‐to‐cellheterogeneity with respect to the presence or absence of the molecule. In this study, we used the human mammary carcinoma line 734B and a set of six monoclonal antibodies reactive with PAS‐O to study the basis of this heterogeneity. Extensive Western blot analysis of antibody binding to PAS‐O in milk fat globule membranes and in skim milk revealed that the antibodies all recognized different epitopes of PAS‐O. Moreover, the epitopes were destroyed by periodic acid oxidation, demonstrating their oligosaccharide basis. All six monoclonal antibodies stained the 734B cells heterogeneously. In addition, five clones derived from the parent 734B population also exhibited heterogeneity in the expression of each of the epitopes. An analysis of staining of the 734B clones revealed that, in some cases, certain cells within the cloned population stained with one monoclonal antibody but not with another antibody. Significantly, though, when the 734B cells were treated with neuraminidase prior to antibody staining, most of the heterogeneity was eliminated, and all but one of the monoclonal antibodies stained 90–100% of the cells. This increase in cell staining was matched by an increase in PAS‐O staining on Western blots. We conclude that heterogeneity in PAS‐O expression on 734B cells is due partly to masking of epitopes by sialic acid and a variation (on a cell‐to‐cell basis) in the extent of PAS‐O sialylation.