SSE arrests cell cycle progression at G
/M phase. AGS (A) and B16F10 (B) cells were treated with 50 μg/mL SSE for the indicated incubation times (6, 12, and 24 h), fixed with ice-cold 70% ethanol, and stained with propidium iodide solution and then subjected to flow cytometry for the determination of cell cycle distribution. Expression of cell cycle-related proteins was examined with western blot analysis in SSE-treated AGS (C) and B16F10 (D) cells. The amount of α-tubulin served as the protein loading control, and relative band intensity compared to untreated “control” cells was calculated using ImageJ after normalization to α-tubulin expression. The data represent 3 independent experiments.