Differential effects of TPA and pristane on gene expression and transformation in mouse epidermal cells.

The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) or 2,6,10,14-tetramethylpentadecane (pristane) on gene expression and transformation were examined using two clones (P+, TPA transformation sensitive and P-, TPA resistant) of the mouse epidermal cell line JB6. Results from transformation studies indicated pristane was more efficient, i.e., lower concentrations were required to elicit an equivalent response, in transforming the P+, but not the P-, clone of JB6 compared to TPA. Furthermore, results from these studies demonstrated either TPA or pristane was effective in the transactivation of the chloramphenicol acetyltransferase gene under the regulatory control of most viral promoter/enhancer elements transfected into the P+, but not the P-, clone of JB6. However, if a consensus cAMP response element was linked to the simian virus 40 early promoter, pristane activation was observed in both P+ and P- cells. The differential effects of these two compounds suggest that while they have similar characteristics, they may utilize different pathways to elicit their effects.