Cells grown on a sterile cover slip in six-well tissue culture
plates were treated with compounds for a certain range of time. The
culture medium containing compounds was removed, and the cells
were fixed in 4% paraformaldehyde for 10 min. After being washed
twice with PBS, the cells were stained with 0.5 mL of Hoechst
33258 (Beyotime) for 5 min and then againwashed twice with PBS.
The stained nuclei were observed under a Nikon ECLIPSETE2000-S
fluorescence microscope using 350 nm excitation and 460 nm
emission.