A new common marker for premalignant and malignant hepatocytes induced in the rat by chemical carcinogens.

A new common antigen, preneoplastic (PN), was found in every early and late hyperplastic nodule and in every primary hepatoma induced by N-2-fluorenylacetamide, ethionine, 3-methyl-4-dimethylaminoazobenzene, dimethylnitrosamine, or diethylnitrosamine in three strains of rats (CFN, F344, and BUF). It so far has not been found in normal adult rat liver, liver surrounding nodules or cancer, fetal liver, amniotic fluid, adult rat serum, sera from rats with hyperplastic nodules or primary hepatomas, or various normal rat tissues. Immunofluorescent staining indicated the PN antigen was present in the cytoplasm of hepatocytes in hyperplastic nodules and in primary hepatomas.