Alteration of cell cycle‐related protein levels induced by JTE‐607 and effect of N‐acetyl‐L‐cysteine (LNAC) on apoptosis in U‐937 cells. (A,B,C) U‐937 cells were cultured with indicated concentrations of JTE‐607 for 1 or 2 days, then cell cycle‐related proteins were detected by Western blotting. Panel (B) shows data from a duplicate experiment, and representative images from multiple experiments are shown in the panels. (D) U‐937 cells were cultured in the presence of JTE‐607 and/or indicated concentrations of LNAC for 2 days, and were stained FITC‐labeled anti‐Annexin V and PI, then analyzed using a flow‐cytometer. Each bar represents the mean of duplicate measurements.