Interactions of tumor cells with intact capillaries: a model for intravasation

Abstract

The interactions of metastatic variants of the B16 and K-1735 melanoma cell lines with intact capillaries isolated from rabbit brain were studied in vitro. The abilities of various cells to attach to and flatten out on the surface of blood vessels were monitored with phase contrast and scanning electron microscopy. In general, cells highly metastatic in vivo were capable of attaching to and flattening out on the surface of capillaries at a faster rate than cells of low metastatic potential or normal cells. In addition, K-1735 melanoma cells and normal fibroblasts were labeled with 125I-iododeoxyuridine, incubated with capillaries, and subsequently passed through filters. This procedure separated unattached cells from cells attached to capillaries. This assay provided quantitative information on the adhesion of metastatic tumor cells and normal cells to capillaries. Tumor cells attached to capillaries in significantly greater numbers than normal cells. Cells with high metastatic potential attached to the capillaries in greater numbers than cells with low metastatic potential, but not significantly. This model may be useful for elucidating some of the mechanisms involved in tumor cell attachment and penetration of the capillary wall during intravasation in vivo.

Characterization of the Gene Expression Profile of Human Hippocampus in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis

“…MVECs were isolated as described by [14, 15]. Briefly, ependym, large vessels and pia membrane were dissected away with the help of a microscope, and the remaining tissue minced and homogenized with a 10 mL-syringe in 10 mL MCDB 131 medium (Gibco, Invitrogen, Basel, Switzerland), containing 2% FBS (PAA Laboratories, Linz, Austria), 16 U/mL heparin (Sigma, Fluka Chemie, AG Buchs, Switzerland), 20  μ L BBE, 5  μ L hEGF, 5  μ L hydrocortisone, 5  μ L FGF (all from Cell System Inc. Kirkland.…”

Differential expression of cell surface glycoproteins on various organ‐derived microvascular endothelia and endothelial cell cultures

“…The tissue homogenates were washed twice by centrifugation in 15-50 ml PBS and filtered sequentially through 150-pm and then 50-pm mesh nylon screens to obtain endothelial microvessels. Brain homogenates were fractionated by centrifugation in a 20% dextran solution to remove myelin (Repesh and Fitzgerald, 1984) before the nylon screen filtration. The 50-pm nylon-screen retentate contained a n enriched fraction of endothelial microvessels, as determined by observing both the retentate and the filtrate by phase contrast and scanning electron washed twice in PBS and solublized in buffer containing 0.5% NP-40, 5mM CaC12, 30 pg/ml DNase, and a cocktail of protease inhibitors (2 mM PMSF, 5 mM EDTA, 5 mM NEM, 5 mM benzamidine, 13 mU/ml aprotinine, 20 pg/ml leupeptin, 0.1 mM TPCK, and 50 mM aminocaproic acid) overnight at 4°C.…”

Organ specificity of tumor metastasis: role of preferential adhesion, invasion and growth of malignant cells at specific secondary sites

“…Using three metastatic and three nonmetastatic tumor cell lines, they found that only the metastatic cells were able to adhere to and invade lung tissue. Using metastatic variants of B16 and K-1735 melanoma, Repesh and Fitzgerald [252] studied the ability of these tumor sublines to attach to and invade the external surfaces of isolated syngeneic brain capillaries. In general, only the highly metastatic cells were capable of attaching to and invading the capillary surfaces.…”