Induction of DNA single strand breaks by 4-OHEN measured using the comet
assay. Cells were treated with various concentrations of 4-OHEN for 90 min
in S30 and MDA-MB-231 cells. A, squares, 4-OHEN in S30 cells;
circles, 4-OHEN in MDA-MB-231 cells. B, closed squares,
4-OHEN in S30 cells; open squares, 4-OHEN + 4-OHTAM (10
nm, 1 h) in S30 cells; closed circles, 4-OHEN + ICI
182,780 (1 μm, 24 h) in S30 cells. C, closed circles,
4-OHEN in MDA-MB-231 cells; open circles, 4-OHEN + 4-OHTAM (10
nm, 1 h) in MDA-MB-231 cells. Data represent the mean ± S.E.
(n = 3).