Figure 3.

Adhesion of MDA-MB-231/THP1 heteroaggregates to endothelium. A suspension of MDA-MB-231/THP1 aggregates was prepared as described in Fig. 2. The suspension was perfused at 0.5, 1 and 2 dyn/cm² on top of TNF-α-activated HAECs, and the number of adherent MDA-MB-231 cells was surveyed by fluorescence and bright-field microscopy. A) In cell suspension not treated with TNF-α, only THP1 cells (red) bind to the endothelium, but in cell suspension treated with TNF-α, MDA-MB-231/THP1 heteroaggregates (green-red) bind to the endothelium. Arrows represent aggregates attached to endothelium. Scale bars = 20 μm. B) Number of adherent MDA-MB-231 cells (in heteroaggregates) was calculated from 5 fields of view. Results are expressed as means ± sd of a representative experiment performed in triplicate; experiments were performed 3 times. *P < 0.01 vs. untreated controls.