Epithelial-mesenchymal transition events during human embryonic stem cell differentiation
Epithelial-mesenchymal transition events during human embryonic stem cell differentiation
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DOI：
10.1158/0008-5472.can-07-2253
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发表时间：
2007-12-01
期刊：
影响因子：
11.2
通讯作者：
Ward, Christopher M.
中科院分区：
文献类型：
--
作者：
Eastham, Angela M.;Spencer, Helen;Ward, Christopher M.
上皮-间质转化（EMT）发生在胚胎发育过程中，也可能与上皮肿瘤的转移扩散有关。在EMT期间，E-钙粘蛋白下调，这与细胞运动性和侵袭性增加相关。我们发现，在单层培养的人胚胎干细胞（ES）的分化与E-到N-钙粘蛋白开关，波形蛋白表达增加，上调E-钙粘蛋白阻遏分子（蜗牛和蛞蝓蛋白），并增加明胶酶（基质金属蛋白酶; MMP-2和MMP-9）的活性和细胞运动，所有特征EMT事件。5 T4癌胚抗原，以前被证明与早期人类胚胎干细胞分化，也是这一过程的一部分。使用中和抗体（nAb）SHE78.7在未分化的ES细胞中消除E-钙粘蛋白介导的细胞-细胞接触导致细胞运动性增加、肌动蛋白细胞骨架排列改变和间充质表型以及5 T4抗原在细胞表面的呈递。nAb处理的ES细胞保持在未分化状态，如通过OCT-4蛋白表达所评估的，并且不表达EMT相关转录物。从ES细胞中去除nAb导致细胞-细胞接触恢复，细胞表面5 T4缺失，间充质细胞形态和运动性降低，并且使得细胞在从成纤维细胞饲养层中去除后能够分化为三个胚层。我们的结论是，E-钙粘蛋白在人ES细胞的功能，以稳定皮质肌动蛋白cyoskeleton的安排，这可以防止5 T4抗原的细胞表面定位。此外，人ES细胞是研究胚胎发育和肿瘤细胞转移相关EMT事件的有用模型系统。
Epithelial-mesenchymal transition (EMT) occurs during embryonic development and may also be associated with the metastatic spread of epithelial tumors. During EMT, E-cadherin is down-regulated and this correlates with increased motility and invasion of cells. We show that differentiation of human embryonic stem (ES) cells in monolayer culture is associated with an E- to N-cadherin switch, increased vimentin expression, up-regulation of E-cadherin repressor molecules (Snail and Slug proteins), and increased gelatinase (matrix metalloproteinases; MMP-2 and MMP-9) activity and cellular motility, all characteristic EMT events. The 5T4 oncofetal antigen, previously shown to be associated with early human ES cell differentiation, is also part of this process. Abrogation of E-cadherin-mediated cell-cell contact in undifferentiated ES cells using neutralizing antibody (nAb) SHE78.7 resulted in increased cellular motility, altered actin cytoskeleton arrangement and a mesenchymal phenotype together with presentation of the 5T4 antigen at the cell surface. nAb-treated ES cells remained in an undifferentiated state, as assessed by OCT-4 protein expression, and did not express EMT-associated transcripts. Removal of nAb from ES cells resulted in the restoration of cell-cell contact, absence of cell surface 5T4, decreased mesenchymal cellular morphology and motility, and enabled the differentiation of the cells to the three germ layers upon their removal from the fibroblast feeder layer. We conclude that E-cadherin functions in human ES cells to stabilize the cortical actin cyoskeletal arrangement and this prevents cell surface localization of the 5T4 antigen. Furthermore, human ES cells represent a useful model system with which to study EMT events relevant to embryonic development and tumor cell metastasis.