The incorporation of 6-thioguanine into RNA fractions and its effect on RNA and protein biosynthesis in mouse sarcoma 180 ascites cells

S W Kwan, S P Kwan, H G Mandel
1973 Cancer Research  
We examined the incorporation of 6-thioguanine into the RNA of Sarcoma 180 to determine the relative distribution of this drug in the various RNA fractions. 6-Thioguanine-3 s S was recovered from ribosomal RNA, transfer RNA, and rapidly labeled RNA (probably messenger RNA) as the intact compound. The incorporation of the analog into microsomal RNA was inhibited by actinomycin D and was enhanced by azaserine. 6-Thioguanine caused an immediate decrease of uridine labeling of the cytoplasmic
more » ... mal RNA and transfer RNA; at the same time, protein biosynthesis was inhibited. Maximal inhibition was observed 3 to 4 hr after the administration of the base analog. No inhibition of uridine labeling of the rapidly labeled cytoplasmic RNA was evident until 3 hr after drug treatment. The possible role of macromolecular effects of thioguanine on growth inhibition is discussed.
pmid:4574059 fatcat:s4aomemhjjegpndmzioa5cejwi