Chemical carcinogenesis in the hamster cheek pouch. Influence of inhibitors and inducers of alkaline phosphatase.

Squamous cell carcinomas were induced in the hamster cheek pouch with 9,10-dimethyl-1,2-benzanthracene. The process of carcinogenesis was inhibited by phenylphosphate, an inducer of alkaline phosphatase. Orthophosphate and l-phenylalanine, which inhibit alkaline phosphatase, had a promoting effect on tumor formation. The results are in accordance with those of previous studies on the effect of inducers of alkaline phosphatase on chemical carcinogenesis. The effect of the studied substances on carcinogenesis was apparently unrelated to the presence of phenyl or phosphate groups or of steroid rings. The tumor inhibition or promotion seemed to be related to the potential of the tested substances to induce or inhibit alkaline phosphatase activity.