Establishment and characterization of a tumorigenic murine vascular endothelial cell line (F-2).

A new murine cell line, designated F-2, was established from an ultraviolet light-induced tumor which developed on the back skin of a BALB/c x C57BL/6 F1-nu/nu nude mouse. More than 1 x 10(5) F-2 cells injected into nude mouse skin produced rapidly developing hemangiomatous lesions. F-2 had a 14-h doubling time under 10% fetal calf serum-containing Dulbecco's modified Eagle's medium culture conditions without any cell growth factor supplementation, and it showed "cobblestone" appearance at confluency. F-2 was able to rapidly differentiate on Matrigel with resultant fine network structure and tubule formation. Ultrastructural observations of the tubule demonstrated that the F-2 cells were connected to each other by intermediate junctions and arranged to form spaces, but that no Weibel-Palade bodies were found in the cytoplasm. F-2 also showed the active uptake of fluorescent-labeled acetylated low-density lipoprotein at 37 degrees C but not at 4 degrees C, and it showed prominent binding to the lectin, Griffonia simplicifolia I agglutinin. The addition of fibroblast growth factor did not facilitate the growth of F-2 cells. These findings strongly suggest that F-2 is a transformed cell line with tumorigenicity and vascular endothelial cell properties, and it may be useful in the study of vascular tumor biology.