Culturing tumor endothelial cell (HBTAEC) in the vascular compartment for 48 h significantly
decreased permeability compared to bMTM with no cells. Permeability of the fluorescent 40 kD dextran from
vascular compartment to the tumor compartment in a cell-free bMTM were quantified by normalizing the
fluorescent intensity in the tumor to the vascular compartment while fluorescent dextrans diffuse from the
vascular compartment to the tumor compartment (panel A). Permeability increased when endothelial cells were
treated with TNF-α but was still significantly lower than in cell-free bMTM (panel B). Data are presented as
mean ± SEM (n = 3). *Significant difference by ANOVA.