Differential effects of butyric acid on mouse skin tumorigenesis.

We studied the effects of butyric acid (BA) on mouse skin tumorigenesis using chronic animal bioassays. Topical application of BA immediately after each treatment with 12-0-tetradecanoylphorbol-13-acetate (TPA) promoter-inhibited skin tumors. The effect was dependent on the dose of BA applied. BA showed no marked inhibitory effect on either skin tumor initiation or complete tumorigenesis induced by dimethylbenzanthracene (DMBA). Since tumor promotion reportedly involves epigenetic events whereas tumor initiation or complete tumorigenesis takes place through genetic pathways, it is possible that BA exerts its antitumorigenic effects mainly by altering the epigenetic events responsible for tumor promotion. The results of the study could further be used to study the mechanism of action and modification of antitumorigenic effects of BA in combination with other substances.