Nuclear deprimerones in rat liver and Novikoff hepatoma.

Extraction of total low molecular weight peptides controlling transcription (deprimerones) from rat liver and Novikoff hepatoma nuclei was perfromed with 80% ethanol at pH 9.5. The extracted material was fractionated on a Sephadex G-25 column and active peptidic fractions were collected as Sephadex fraction II of mol. wt. between 1600 and 600. The yield of this peptide fraction was 600 micrograms/mg DNA from rat liver nuclei and 200 micrograms/mg DNA from Novikoff hepatoma nuclei. The results confirm a previously found decrease in chromatin deprimerones in tumor cells using different experimental approach and remain in accordance with the postulated deprimerone theory of carcinogenesis.