QCE-6: a clonal cell line with cardiac myogenic and endothelial cell potentials.

A clonal cell line (QCE-6) sharing many properties with splanchnic mesodermal cells has been derived from 20-methylcholanthrene-treated cardiogenic mesoderm of the Japanese quail. QCE-6 cells which have been stably maintained for over 4 years in vitro display positive staining with antibodies to cytokeratin, vimentin, cingulin, and N-cadherin but were negative for markers of endothelial, fibroblastic, smooth, and skeletal muscle cell lineages. In the present study, we show that addition of retinoic acid and growth factors initiated cardiomyogenic differentiation in approximately 50% of QCE-6 cells as indicated by the expression of muscle- and cardiac-specific proteins. The distribution of these proteins in induced cells was similar to precontractile cardiac myocytes. In addition to these myogenic cells, cultures of induced QCE-6 cells contained endothelial cells as visualized by the presence of QH1 antigen and extracellular matrix molecules associated with endothelial cells. These data demonstrate that the QCE-6 cell is a progenitor of both cardiac myogenic and endothelial cell lineages and along with other recent studies (Linask and Lash, 1993; Garcia-Martinez and Schoenwolf, 1993) suggest that these two cell lineages may have a common embryonic origin.