Benzoyl peroxide modulates gene expression by epigenetic mechanism in mouse epidermal JB6 cells.

The mechanism by which an oxidant tumor promoter benzoyl peroxide (BP) influences signal transduction, was studied in promotion insensitive (P-), promotion sensitive (P+) and transformed (Tx) mouse epidermal JB6 cells. The basal levels of antioxidant enzymes CuZn-superoxide dismutase and catalase were higher in P+ and Tx JB6 cells. BP decreased the activities of these enzymes transiently in P+ and Tx cells, but induced them in P- JB6 cells. BP increased poly ADPR polymerase activity accompanied by a drop in NAD+ levels more significantly in P- JB6 cells, but did not affect PKC activity. It induced c-jun and c-fos gene expression in JB6 variants but to different extents, suggesting that it mediates its effects via genetic- epigenetic mechanism(s).