Prostaglandin modulation of phorbol ester skin tumor promotion

Abstract

TPA promotion of skin tumors in mice can be modified by application of various prostaglandins or their precursors. The effects depend on the particular prostaglandin used: PGF2alpha enhances promotion, whereas PGE1 consistently inhibits promotion. Time of application of the prostaglandin with respect to TPA determines whether PGE2 enhances or inhibits. Dose-dependent inhibition was observed for arachidonic acid. The prostaglandins alone were unable to elicit tumors in initiated mice.