Differential inhibition of the in vivo synthesis of adenovirus type 5-specific ribonucleic acids by cordycepin

Modulation of production of hepatitis B surface antigen by a human hepatoma cell line

Three drugs were assayed for their capacity to inhibit hepatitis B surface antigen (HBsAg) production by the PLC/PRF/5 human hepatoma cell line. The effect on cell growth and HBsAg production of Cordycepin, 6-azauridine, and Hygromicin B is reported. Hygromicin B, a translation inhibitor unable to penetrate normal cells, greatly reduced HBsAg production by growing and confluent cells.

The effect of cordycepin on the multiplication of Semliki Forest virus and on polyadenylation of viral RNA

Cordycepin (3'-deoxyadenosine), at a concentration of 20 microgram/ml, has a marked effect on Semliki Forest virus multiplication. The appearance of plaque forming units is delayed by about 2 hours and the yield greatly reduced. The incorporation of [3H] uridine into intracellular viral RNAs reaches less than 50 per cent of controls. However, no specific effect on poly (A) synthesis could be detected. The binding efficiency of viral RNAs on nitrocellulose membranes and poly (U) sepharose is not affected by cordycepin. The average poly (A) length of total intracellular viral RNA was calculated on the basis of the ratio of the radioactivity of adenosine-monophosphate: adenosine and found to be about 35 nucleotides in treated and untreated cells.