Brief Communication: Inhibition of Tumor Promotion by a Neutral Fraction of Cigarette Smoke Condensate

Cigarette smoke condensate (CSC) and 2 neutral subfractions were applied to mouse skin concurrently with the tumor promoter 12-O-tetradecanoyl phorbol13- acetate (TPA) after initiation with 7,12-dimethylbenz[a] anthracene. The ether-soluble neutral fraction, which has marginal tumor-promoting activity, inhibited the promoting effect of TPA, as measured by a delayed tumor appearance and a reduction in the number of tumor-bearing mice. Neither the benzo[a]pyrene-containing fraction nor crude CSC altered the promoting activity of TPA