The endothelin B receptor antagonist A-192621 decreases glioma cell proliferation. (A) A-192621 suppresses cell proliferation. LN-229 and SW1088 cells were stained with CFSE and analyzed by FACS at 9, 24, 48 and 72 h after addition of A-192621. The exponential dilution of CFSE was converted to the number of cell divisions. (B) A high concentration of A-192621 (100 μM) induces G2/M cell cycle arrest in both LN-229 and SW1088 cells by 72 h. Cells were pulsed-labeled with BrdU, stained with propidium iodide and analyzed by FACS. Values are expressed as means of three replicates ± SEM. Symbols for statistical significance as compared with vehicle-treated controls are displayed at the bottom of the figure and are applicable to all panels.