|Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥2,000,000 (Direct Cost: ¥2,000,000)
The permeation of macromolecular FITC-labeled dextran (Mw=70,000) through bovine aortic endothelial cells (BAEC) monolayr, which were cultured for 5 days with conditioned medium prepared from mouse melanoma B16, was increased. However, when BAEC,which were cultured with normal medium until confluent, were treated with B16 conditioned medium (B16-CM) for 30 min, the permeability did not increase. The B16-CM also increased the permeability of the endothelial monolayrs of bovine veins and the human umbilical vein, but did not increase that of the epithelial monolayr. The B16-CM did not alter the distribution or content of F-actin on the BAEC.BAEC cultured in the presence of B16-CM for 5 days were detached from the dish, and then seeded into a chamber at one-fifth of confluent cell density. After 5 days of culture in nomal medium, the BAEC were grown to confluence and their permeability was increased. These findings suggest that B16-CM increased the endothelial permeability irreversibly wi
thout the decrease of F-actin, and that soluble factor (s) which were secreted from the tumor cells participate in the construction of the hyperpermeable structure of tumor vessels in vivo.
Rat KMT-17 fibrosarcoma-derived endothelial cells were isolated by Percoll gradient centrifugation with an attaching-speed separation technique, and their properties in culture were examined. The primary cultured 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 cultured TEC monolayr showed greater permeability than normal tissue-derived endothelial cell (aorta, vena cava and epididymal fat capillary) monolayrs 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 vascular endothelium, and were observed both in the primary and first-passage cell cultures, but not in the fourth-passage cell cultures. Our findings indicate that primary or subcultured TEC are applicable for studies of the physiological characteristics of tumor endothelial cells. Less