ISOLATION AND PROPERTIES OF TUMOR-DERIVED ENDOTHELIAL-CELLS FROM RAT KMT-17 FIBROSARCOMA

Rat KMT-17 fibrosarcoma-derived endothelial cells were isolated by Per coll gradient centrifugation with an attaching-speed separation techni que, and their properties in culture were examined. The primary cultur ed tumor-derived endothelial cells (TEC) showed angiotensin-converting enzyme activity, positivity for Factor VIII-related antigen staining, and typical capillary-like formation on Matrigel. The primary culture d TEC monolayer showed greater permeability than normal tissue-derived endothelial cell (aorta, vena cava and epididymal fat capillary) mono layers on FITC-dextran diffusion (molecular weight 70,000). Leukocyte adhesion to TEC was reduced compared to that to fat-derived capillary endothelial cells. These characteristics resembled those of tumor vasc ular endothelium, and were observed both in the primary and first-pass age cell cultures, but not in the fourth-passage cell cultures. Our fi ndings indicate that primary or subcultured TEC are applicable for stu dies of the physiological characteristics of tumor endothelial cells.