TXA inhibits cell migration of MDA-MB-231 BAG breast cancer cells in vitro. Two cell lines were studied: the MDA-MB-231 BAG breast cancer cell line (A-B) and the OVMZ6 ovarian adenocarcinoma cell line (C-D). Inhibition of cell migration by TXA is observed in MDA-MB-231 BAG cells (A) but not in the OVMZ6 cell line (C). (B) Endogenous uPA and Plm activities were detected in MDA-MB-231 BAG cells (panel i is the same as panel B with a reduced scale on the y-axis for better illustration). (Bii) The endogenous uPA activity (250 000 cells per reaction) was inhibited by TXA (0-50 mM) in a dose-dependent manner. (D) No uPA activity was recorded in OVMZ6 cells, but a high level of Plm activity (∼30 times that of MDA-MB-231 BAG cells) was recorded. The Transwell cell-migration assay was performed by incubation of cells with TXA at 0, 0.2, 1, and 5 mM or with EACA at 5 mM for 30 minutes,²³  after which migration was allowed to occur at 37°C for 3 hours. Cells were stained with a Quick Dip staining kit (Fronine) and imaged with an Olympus IX71 microscope at ×200 magnification. Migrated cell numbers were counted and averaged from 10 individual microscopic frames in duplicate conditions and plotted as a percentage of 0 mM TXA. Endogenous Plm and uPA activity was measured (as for Figure 1A) using fluorogenic substrates (as for Figure 1C) on a range of cell number inputs. All data points represent the mean ± standard deviation of ≥3 independent experiments. Both cell lines were maintained at 37°C with 5% CO₂ in Dulbecco’s modified Eagle medium supplemented with 10% fetal bovine serum, penicillin (50 U/mL), and streptomycin (50 μg/mL). **P < .005, ***P < .0005, 1-way analysis of variance using GraphPad Prism. AFU, arbitrary fluorescence units.