ABSTRACT
The antitumour activity of an interferon inducer, the double-stranded complex of polyriboguanylic.polyribocytidylic acid was studied on murine lymphosarcoma LS/BL. The antitumour effect was determined with the aid of an experimental liver-colony model and compared to that exhibited by another synthetic RNA, polyriboinosinic.polyribocytidylic acid. We found that both polynucleotide complexes decreased the number of liver colonies and prolonged the survival of the tumour-bearing mice. This effect was only observed if the complexes were applied in an appropriate dose schedule which included the administration of the drug prior to tumour cell inoculation and subsequent continuous treatment. We have also verified that the polynucleotide complexes did not exert their antitumour effect by a direct action on tumour cells.
Subject(s)
Interferon Inducers/therapeutic use , Liver Neoplasms, Experimental/prevention & control , Liver Neoplasms, Experimental/secondary , Poly C/therapeutic use , Poly G/therapeutic use , Animals , Female , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Poly I-C/therapeutic useABSTRACT
Conformation of double-stranded complexes of polyriboguanylic acid with halogenated polyribocytidylic acid [poly(C)] was studied with the aid of differential pulse polarography, terbium fluorescence and circular dichroism spectrometry. It was shown that halogenation at C(5) of cytosine residues in poly(C) disturbed the ordered structure of the double-helical complex. In addition, this halogenation does not improve antiviral activity of the polynucleotide complex studied in the system of vesicular stomatitis virus and the cell culture of chicken embryos. It was concluded that the regularity of the secondary structure of synthetic RNAs might play an important role in the mechanism of biological activity of these biomacromolecules.
