Cadherin switching: essential for behavioral but not morphological changes during an epithelium-to-mesenchyme transition

Abstract

Epithelium-to-mesenchyme transitions (EMTs) are characterized by morphological and behavioral changes in cells. During an EMT, E-cadherin is downregulated while N-cadherin is upregulated. The goal of this study was to understand the role cadherin switching plays in EMT using a classical model system: transforming growth factor β1 (TGF-β1)-mediated EMT in mammary epithelial cells. We showed that stress fibers and focal adhesions are increased, and cell-cell junctions are decreased in response to TGF-β1. Moreover, these changes were reversible upon removal of TGF-β1. Downregulation of E-cadherin and upregulation of N-cadherin were both transcriptional. Neither experimental knockdown nor experimental overexpression of N-cadherin interfered with the morphological changes. In addition, the morphological changes associated with EMT preceded the downregulation of E-cadherin. Interestingly, TGF-β1-induced motility in N-cadherin-knockdown cells was significantly reduced. Together, these data suggest that cadherin switching is necessary for increased motility but is not required for the morphological changes that accompany EMT.

Regulation of vimentin by SIP1 in human epithelial breast tumor cells

“…Indeed, a high level of SIP1 has been detected during the formation of the neural tube and this has been shown to play a key role in the migration of neural crest cells (Eisaki et al, 2000;van Grunsven et al, 2000;, a system largely described as a physiological archetypal model of EMT (Duband et al, 1995;Tucker, 2004). Also, an increased expression of SIP1 has been described in NMuMG cells which have undergone a TGFβ1-induced EMT characterized by decreased E-cadherin expression and increased N-cadherin expression (Maeda et al, 2005). Our results thus demonstrate a relationship between SIP1 and an EMT-derived phenotype characterized by vimentin expression, and further emphasize the implication of this relationship in dynamic cell migration.…”

Reduced Expression of E-cadherin and β-catenin and High Expression of Basal Cytokeratins in Feline Mammary Carcinomas With Regional Metastasis

“…In reports studying human breast cancer, some authors claim that vimentin is one of the first steps in carcinoma progression and that these vimentin positive cells are prone to develop subsequent EMT changes, such as loss of cadherins. 17 In the field of veterinary pathology, the carcinogenesis of canine mammary tumors has been widely studied, 12 and several attempts have been made to establish a model of a molecular-based subgrouping of malignant tumors similar to that developed for human breast cancer. 9,35 To our knowledge, no studies on molecular subgrouping have been performed in feline mammary tumors, although the loss of hormone receptors in tumor progression is well known, 19,21,23 and several reports have evaluated the role of HER-2 overexpression in mammary carcinomas of cats.…”

The regulatory or phosphorylation domain of p120 catenin controls E-cadherin dynamics at the plasma membrane

“…Protein concentration was determined using a BioRad protein assay kit (Bio-Rad, Hercules, CA). TNE extracts were used for immunoprecipitation as described [20]. In experiments comparing soluble vs. insoluble proteins, we used the detergent solubility assay described by Gimond et al [21], where the detergent insoluble pellet was resuspended in SDS sample buffer (2% SDS, 10% glycerol, 62.5 mM Tris-HCl, pH 6.8) followed by sonication.…”

“…Constructs were inserted into pLZRS and transfected into Phoenix 293 cells using a TransIT-LT1 Reagent (Mirus, Madison, WT). Conditioned medium containing recombinant retrovirus was supplemented with 4 μg/ml polybrene and added to target cells as described [20,30].…”