Influence of Synthetic (Poly I:C) and Viral Double-Stranded Ribonucleic Acids on Adenovirus 12 Oncogenesis in Hamsters ∗

Abstract

Summary

Synthetic double-stranded ribonucleic acid (Poly I:C) and replicative form RNA from MU9 coliphage reduced the occurrence of internal but not subcutaneous tumor after injection of adenovirus 12 subcutaneously into newborn hamsters. The effect was more evident in female than in male animals. Poly I:C treatment was consistently effective only when started prior to virus. The single homopolymers Poly I and Poly C were also protective even though they exert little, if any, interferon-inducing capacity. The action of the ribonucleotides might have been related both to interferon and to ordinary immune mechanisms. The greater activity in females as compared with male animals and the fact that the single-stranded Poly I and Poly C homopolymers were active favors the latter possibility. Pyran copolymer and endotoxin showed a minor reduction in internal but not subcutaneous tumor when given prior to and after adenovirus.