CPT induces single-strand breaks in a transcription- and
proteasome-dependent manner in quiescent WI-38 cells.
a, WI-38
cells cultured in DMEM supplemented with 0.2% serum were pretreated with APH
(10 μm), DRB (150 μm), or MG132 (2
μm) for 30 min, followed by co-treatment with CPT (25
μm) for 1 h. SSBs were analyzed by alkaline comet assay as
described under “Experimental Procedures.” Left panel,
representative comet images. Right panel, the histogram of the tail
moment plotted against each treatment condition. b, WI-38 cells
cultured in DMEM supplemented with 0.2% serum were treated with
Me2SO or CPT (25 μm) for 1 h. DSBs were analyzed by
neutral comet assay as described under “Experimental Procedures.”
Upper panel, representative comet images. Lower panel, the
histogram of the tail moment.