Action of Daunomycin on Nucleic Acid Synthesis in Hepatoma Ascites Cells Incubated « in vitro »

Abstract

The action of Dannomycin, an antibiotic of Rhodomycin group, was studied following the incorporation of Adenine-8-¹⁴C into nucleic acid of hepatoma ascites cells incubated « in vitro ». Doses of 20 μg/ml of the antibiotic were able to inhibit the uptake of the precursor by RNA; the activity of the drug appeared to be dependent on the density of the cell population. As it was noted that, under our experimental conditions, a partial inhibition of the incorporation was caused by these doses of Daunomycin, some RNA fractions were isolated from cells and tested for their sensitivity to the antibiotic. A high-activity RNA extracted from nuclei appeared to be the most sensitive to the Daunomycin action. At higher doses of Daunomycin the incorporation into DNA was also lowered.