in the Treatment of Malignancies

ABSTRACT The mechanism of the antitumor action of polyinosinic-poly-cytidylic acid is probably multifaceted. The compound induces the synthesis of interferon, and interferon probably is active against some tumors. Poly I: poly C alters protein and RNA synthesis in tissue culture. It specifically in-hibits such macromolecule synthesis in tumors in vivo, while having less in-hibitory action on synthesis in normal organs, or it may actually enhance. Finally, poly I:poly C strongly enhances graft vs. host rejection mechanisms, which may play a role in the rejection of some tumors. It was originally proposed by Isaacs that the interferon response is induced by the presence in a cell of a foreign nucleic acid. The net effect of this response is, in effect, to reduce the damage brought about by the presence of this foreign nucleic acid, which usually would be viral nucleic acid. Isaacs' hypothesis was supported by some data showing that foreign nucleic acids do indeed lead to the production of some slight amount of interferon. His data were not very convincing, and general acceptance of this concept wa