Isolation and identification of fresh tumor-derived endothelial cells from a murine RIF-1 fibrosarcoma

Tumor vasculature is anatomically heterogeneous and distinct from the vasculature found in normal mature tissues. Examination of the differences between tumor and normal vasculature is critical to the future design of therapeutic modalities which either target tumor vasculature or potentially enable more efficient delivery of tumor cytotoxic agents. Such efforts to date have been hampered due to the inability to isolate live endothelial cells from solid tumors. We report here the isolation of fresh, noncultured endothelial cells from a C3H/HeJ RIF-1 murine fibrosarcoma through the use of fluorescence-activated cell sorting based on antibody staining for angiotensin-converting enzyme with further characterization by uptake and metabolism of acetylated low-density lipoprotein, factor VIII staining, and electron microscopy.