An in vitro model to study mesenchymal-epithelial transformation.

Mesenchymal-epithelial transformation (MET) is an important process in the embryogenesis of organisms. In an attempt to study the mechanism of MET, we present here the identification of a cloned human chondrosarcoma cell line, the SW1353, that is capable of converting to cells with an obvious epithelial phenotype. The transformation of the fibroblast-like SW1353 cells to epithelial cells occurred in a defined culture condition and the transformed cells displayed features characteristic expected to be epithelial cells and formed aggregates with cobblestone appearances. We also demonstrated that SW1353 cells not only secreted hepatic growth factor (HGF)/scatter factor (SF) but also expressed large amounts of p140c-met, the receptor tyrosine kinase for HGF/SF. These results suggest that mesenchymal cells, like epithelial cells, are able to express c-met proto-oncogene product, and the SW1353 cell culture system can provide us with a potential avenue to identify genes responsible for MET.