Establishment and preliminary growth characteristics of a transformed mouse cerebral microvessel endothelial cell line.

A clone of spontaneously transformed mouse cerebral microvessel endothelial cells has been characterized and its growth characteristics have been investigated. The clone has been designated TEn and has been derived from parent nontransformed cerebral microvessel endothelial cells after multiple passages in culture. These transformed endothelial cells maintained characteristics of other transformed cells: anchorage-independent growth in soft agar, nude mouse tumorigenicity, and growth to high saturation density in culture with lack of contact inhibition. Although transformed, these cells still maintained endothelial functions and markers. These cells respond to both epidermal growth factor and platelet-derived growth factor. Although the TEn cells utilize serum factors for growth, they have maintained in completely serum-free media for up to 3 months. Additionally, serum-free media conditioned by these cells contained a growth factor-like activity that was mitogenic for the nontransformed parent endothelial cells. The TEn cells' maintenance of endothelial functions, growth in serum-free media, production of growth factor-like activity, and the response to well-characterized purified mitogens (epidermal growth factor and platelet-derived growth factor) suggest that these cells may be useful in studying growth control of cerebral microvessel-derived endothelial cells as well as in studies of growth factor production by transformed cells.