Fig. 4

Impact of UBC cell SN on the integrity of the endothelial cell layer. a HUVECs grown on gelatine coated ECIS electrodes were treated with starvation medium (control) or UBC cell SN. The impedance was measured continuously up to 12 h after treatment. T24 cell SN led to marked breakdown of the endothelial impedance. RT4 cell SN had a lower impact whereas RT112 cell SN, UROtsa cell SN or starvation medium (control) did not cause significant alterations after 12 h; n = 5; ** P ≤ 0.01. b HUVEC cells were incubated for 12 h with T24 cell SN (T24) or starvation medium (control) and then analysed by immunofluorescence staining of β-Actin (red) and CD31/PECAM-1 (green). In comparison to the control (left), treatment with T24 cell SN (right) induced the disintegration of adherent junctions (CD31/PECAM-1) indicating a weakening of the endothelial barrier. c Inhibition of cytokine signalling partially conserved endothelial barrier function. Antibodies against IL-6, CXCL-1 slightly mitigated impedance breakdown. In contrast, IL-1ra strongly attenuated tumour mediated endothelial dysfunction, whereas IL-8 neutralization had no impact; n = 4; ** P ≤ 0.01