Construction of epithelioid sheets by transfection of mouse sarcoma cells with cDNAs for chicken cell adhesion molecules.

Abstract

Pleiomorphic mouse sarcoma S180 cells were transfected with cDNAs for the liver cell adhesion molecule (L-CAM), the neural cell adhesion molecule (N-CAM), or both CAMs. Transfected cells expressed the appropriate CAMs at their surface and those expressing L-CAM (S180L cells) changed from adjoining spindle or round shapes to a closely linked "epithelioid" sheet when grown to confluence. Cells transfected with cDNA for N-CAM (S180N cells) also expressed this CAM on the cell surfaces and bound brain vesicles containing N-CAM but showed no phenotypic change to an epithelioid state. In S180L cells and doubly transfected (S180L/N) cells, L-CAM was concentrated at regions of cell contact and was codistributed with cortical actin. In S180N cells, N-CAM was uniformly distributed on the cell surface. When S180L cells were cocultured with S180L/N cells, N-CAM was not concentrated at boundaries between the S180L and S180L/N cells but was concentrated at boundaries between pairs of S180L/N cells. Fab' fragments of anti-L-CAM dissociated the epithelioid sheets of S180L or S180L/N cells into cells with shapes resembling those of untransfected cells. Cells in epithelioid sheets were polygonal in shape but, unlike cells in true epithelia, had no basement membrane or polar structure; they also lacked tight junctions and desmosomes. Ultrastructural examination showed that, in contrast to the untransfected phenotype, cells in epithelioid sheets had large increases in adherens junctions and gap junctions. Dye coupling experiments indicated that the gap junctions were functional. The frequency of expression of both kinds of junctions was sharply decreased by treatment with anti-L-CAM Fab' fragments. These experiments provide support for the precedence hypothesis, which proposes that the linkage of cells by means of CAMs is a necessary event for the extensive expression of junctional structures.

Mechanism of the Mesenchymal–Epithelial Transition and Its Relationship with Metastatic Tumor Formation

“…In addition to this, it was found that E-cadherin alone can induce MET. As early as 1988, expression of E-cadherin was found to induce MET in pleiomorphic mouse sarcoma S180 cells (65). Reexpression of E-cadherin also induced MET in pancreatic tumor cell line MIA PaCa-2 cells and resulted in upregulation of a-and b-catenin mRNAs and protein concentrations (66).…”

The mesenchymal cell, its role in the embryo, and the remarkable signaling mechanisms that create it

“…Over the years, it has been demonstrated over and over again that transfection of mesenchymal cells with plasmids carrying the E-cadherin gene reverts mesenchyme to epithelium (Nagafuchi et al, 1987;Mege et al, 1988;Chen and Obrink, 1991;Behrens et al, 1992;Hay, 1995;Takeichi, 1995;Vanderburg and Hay, 1996. Transfection of invasive corneal fibroblasts with the E-cadherin gene causes their dramatic transformation from mesenchyme to stratified epithelia with desmosomes (Vanderburg and Hay, 1996).…”

N‐cadherin transcripts in Xenopus laevis from early tailbud to tadpole

“…A series of elegant experiments have shown that fibroblastic cells transfected with cadherins acquire an epitheloid morphology Nagafuchi et al, 1987;Friedlander et al, 1989;Miyatani et al, 1989). Mixed aggregates of transfected cells expressing different levels of cadherin or distinct cadherins will sort out, emphasizing the importance of cadherins in the function of tissue boundaries and positioning of cells within tissues (Matsuzaki et al, 1990;Mege et al, 1988;Nose et al, 1988).…”