Inhibition by squalene of the tumor‐promoting activity of 12‐O‐Tetradecanoylphorbol‐13‐acetate in mouse‐skin carcinogenesis

Abstract
Squalene inhibited the effect of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), such as increased 32Pi incorporation into phospholipids of HeLa cell membrane, induction of Epstein-Barr-virus early antigen in Raji cell and induction of ornithine decarboxylase in mouse skin. Squalene also markedly suppressed the promoting activity of TPA on skin carcinogenesis in 7, 12-dimethylbenz[a]anthracene-initiated mice.