Specific binding ofadaic acid, a new tumor promoter in mouse skin

Abstract
The tumor promoteradaic acid binds specifically to a particulate as well as a cytosolic fraction of various mouse tissues, e.g., skin, brain, lung and colon. The K D value was 21.7 nM for receptors in the particulate fraction and 1.0 nM for those in the cytosolic fraction of mouse skin. The specific binding of [3H]okadaic acid to the particulate fraction of mouse skin was inhibited dose‐dependently byadaic acid, but notaidaic acid tetramethyl ether, an inactive compound, or by other tumor promoters, such as 12‐O‐tetradecanoylphorbol‐13‐acetate and teleocidin. The results suggest a new pathway of tumor promotion mediated through theadaic acid receptor(s).