The vacuolar-type ATPase inhibitor archazolid increases tumor cell adhesion to endothelial cells by accumulating extracellular collagen
Confluent HUVECs were treated either with archazolid or DMSO for 24 h. MDA-MB-231 or PC-3 cells were stained with CellTracker Green CMFDA Dye. (A) The cell adhesion assay was performed after the integrin β1 subunit was blocked by a monoclonal antibody for 30 min on either MDA-MB-231 (n = 6) cells or HUVECs (n = 3). MDA-MB-231 cells were allowed to adhere for 10 min. (B) The cell adhesion assay was performed after the integrin β1 subunit was blocked by a monoclonal antibody for 30 min on either PC-3 cells (n = 5) or HUVECs (n = 3). PC-3 cells were allowed to adhere for 60 min. (A, B) Non-adherent tumor cells were washed off. The adhesion was quantified by measuring the fluorescence signal using a plate reader. Data are expressed as mean ± SEM. *p ≤ 0.05 versus DMSO control, #p ≤ 0.05 versus 1 nM archazolid.