Effect of daunomycin on HeLa cell nucleic acid synthesis

Abstract

In the presence of daunomycin (0.5 μg/ml) HeLa cell DNA synthesis was irreversibly inhibited. RNA synthesis although initially inhibited gradually reversed and returned to normal levels by 24 hr. Analysis showed that the drug selectively inhibited ribosomal RNA and only partially inhibited heterogeneous RNA which was altered in physical characteristics. Inhibition of protein synthesis was a late event indicating the continued synthesis of messenger RNA in the presence of daunomycin. A possible mechanism to explain these differential effects is discussed.