Fig. 1

Soluble E-selectin induces adhesion and migration of CD44^+/high BCs: a Effect of sE-selectin on shear resistant adhesion of BCs to endothelial cells. A monolayer of ES-HMVECs was grown on the flow chamber. For endothelial E-selectin expression, ES-HMVECs were incubated with or without doxycycline (1500 ng/ml) for 4 h. BCs suspensions were incubated with 100 nM sE-selectin for 10 min and then were infused into flow chambers. The shear-resistant adhesion of BC cell lines (10⁵ cells/ml) was tested at 37 °C for 5 min at a rate of 1 dyn/cm². BCs adhering to endothelial cells were counted under a light microscope. Data were expressed as percentage of control (-Dox/-sEselectin as 100 %). b Effect of CD44 knockdown of MDA-MB-231 cells on sE-selectin-induced shear-resistant adhesion. Suspensions of MDA-MB-231 cells with CD44 shRNA or control shRNA clone (10⁵ cells/ml) were treated with sE-selectin or saline and infused into flow chambers after a brief wash. The adhesion of the cells to non-activated ES-HMVECs (-Dox) were counted under a light microscope. Data were expressed as percentage of control (saline treated as 100 %). c Effect of sE-selectin on the migration of BCs. BCs were seeded into the upper chambers (12-μm pore), soluble E-selectin (100 nM) was added to the lower chambers, and plates were incubated overnight at 37 °C. Migrated cells were stained using an HEMA3 staining kit and were counted under light microscopy. Data were expressed as percentage of control (saline treated as 100 %). d Effect of CD44 knockdown of MDA-MB-231 cells on sE-selectin-induced migration. CD44 knockdown clones of MDA-MB-231 cells or control shRNA were added to the upper chambers and migrated cells were counted after overnight incubation at 37 °C. The data represent Mean ± S.D. *p < 0.05; **p < 0.01; ***p < 0.001 vs. saline, Student’s t-test. Data were summarized from an experiment conducted in triplicate and repeated twice