Deman J J, Van Larebeke N A, Bruyneel E A, Bracke M E, Vermeulen S J, Vennekens K M, Mareel M M
Department of Radiotherapy, University Hospital, Gent, Belgium.
In Vitro Cell Dev Biol Anim. 1995 Sep;31(8):633-9. doi: 10.1007/BF02634317.
MCF-7 human breast cancer cells express E-cadherin and show, at least in some circumstances, E-cadherin-dependent cell-cell adhesion (Bracke et al., 1993). The MCF-7/AZ variant spontaneously displays E-cadherin-dependent fast aggregation; in the MCF-7/6 variant, E-cadherin appeared not to be spontaneously functional in the conditions of the fast aggregation assay, but function could be induced by incubation of the suspended cells in the presence of insulinlike growth factor I (IGF-I) (Bracke et al., 1993). E-cadherin from MCF-7 cells was shown to contain sialic acid. Treatment with neuraminidase was shown to remove this sialic acid, as well as most of the sialic acid present at the cell surface. Applied to MCF-7/AZ, and MCF-7/6 cells, pretreatment with neuraminidase abolished spontaneous as well as IGF-I induced, E-cadherin-dependent fast cell-cell adhesion of cells in suspension, as measured in the fast aggregation assay. Treatment with neuraminidase did not, however, inhibit the possibly different, but equally E-cadherin-mediated, process of cell-cell adhesion of MCF-7 cells on a flat plastic substrate as assessed by determining the percentage of cells remaining isolated (without contact with other cells) 24 h after plating.
MCF - 7人乳腺癌细胞表达E - 钙黏蛋白，并且至少在某些情况下表现出E - 钙黏蛋白依赖性细胞间黏附（Bracke等人，1993年）。MCF - 7/AZ变体自发地表现出E - 钙黏蛋白依赖性快速聚集；在MCF - 7/6变体中，在快速聚集试验条件下，E - 钙黏蛋白似乎不具有自发功能，但通过在胰岛素样生长因子I（IGF - I）存在下孵育悬浮细胞可以诱导其功能（Bracke等人，1993年）。已证明MCF - 7细胞的E - 钙黏蛋白含有唾液酸。用神经氨酸酶处理可去除这种唾液酸以及细胞表面存在的大部分唾液酸。应用于MCF - 7/AZ和MCF - 7/6细胞时，用神经氨酸酶预处理可消除悬浮细胞中自发的以及IGF - I诱导的、E - 钙黏蛋白依赖性快速细胞间黏附，这在快速聚集试验中进行测量。然而，通过测定接种24小时后仍保持分离（不与其他细胞接触）的细胞百分比评估，用神经氨酸酶处理并未抑制MCF - 7细胞在平坦塑料底物上可能不同但同样由E - 钙黏蛋白介导的细胞间黏附过程。
