*3.7. Cell Cycle Analysis*

Cell cycles were analyzed by flow cytometry in triplicate. Cells were seeded, treated with PN at 0.5, 1, 2, or 4 μg/mL for 24 h, detached, fixed in ice-cold 70% ethanol, and stained with PI solution containing RNase for 10 min in the dark. Cell cycle distributions were analyzed by flow cytometry (FC 500).
