Establishment of a new murine-phenotypic angiosarcoma cell line (ISOS-1).

A cell line, designated ISOS-1, was established from a tumor formed by transplantation of a human angiosarcoma into mice with severe combined immunodeficiency (SCID). The cells showed endothelial properties, based on the uptake of Dil-Ac-LDL and binding of UEA-I/GSA-I lectins, but were negative for CD11b and Pan Cytokeratin. However, the cells lost differentiated characteristics such as expression of von Willebrand factor, contact inhibition growth and tube formation activity. These findings indicate that ISOS-1 is a poorly-differentiated endothelial cell line. At the 81st passage, all of the cells were positive for H-2Dd in various intensity, but not HLA-ABC. The metaphase chromosomes consistently showed a characteristic mouse, but not human, telocentric form. Furthermore, this cell line produced fatal tumor growth in SCID mice and also in BALB/c mice. These results suggest that ISOS-1 is a murine-phenotypic angiosarcoma cell line.