Flow cytometry assay
For cell cycle analysis, cells treated with or without PDS were harvested and fixed in ice-cold 70% ethanol, stained with 1X PBS based propidium iodide solution (50μg/mL PI, 100μg/mL RNase A, 0.1% sodium citrate, 0.1% Triton X-100), and analyzed by flow cytometry (Agilent).