Establishment of an immortalized Copenhagen rat bone marrow endothelial cell line.

Bone marrow endothelial cells are critical mediators in the processes of cell trafficking as well as cancer metastasis, however few established models exist. An immortal cell line of Copenhagen rat bone marrow endothelium was established after infection of primary cultured cells with Adenovirus-12 SV40 hybrid virus and designated YPBE-1. The established cell line has continued to proliferate more than 70 population doublings and has not undergone "crisis". It stains positively for SV40 T-antigen in its nuclei by immunohistochemistry and grows in a monolayer with a cobblestone appearance. It demonstrates Dil-Ac-LDL uptake as an endothelial marker. YPBE-1 does not express Integrin beta 3 or endothelin, but does express Integrin alpha 6 beta 1 on the plasma membrane and demonstrates tube formation in Matrigel. This cell line of rat bone marrow endothelial origin should be useful for studying mechanisms of bone metastasis and cell trafficking.