all-trans-Retinoic acid inhibits the appearance of two phorbol ester-induced ornithine decarboxylase mRNAs in mouse epidermis.

Two ornithine decarboxylase mRNA species are seen in mouse epidermis in response to the topical application of the phorbol ester tumor promoter, 12-O-tetradecanoyl phorbol-13-acetate (TPA). This induction occurs in a time- and dose-dependent fashion and appears to be relatively specific as alpha-actin mRNA reveals no change with treatment. Both mRNA species are inhibited in a dose-dependent manner by treating mouse skin with all-trans-retinoic acid prior to TPA. These results indicate that these two compounds are active at the transcriptional level.