Role of cellular RNA polymerases in virus-induced leukemogenesis.
Friend murine leukemia virus induces splenic enlargement and an increase in RNA polymerase activity of spleen nuclei. Actinomycin D, administered at 60 mug/kg body weight/day prevents the development os splenomegaly and the elevation of polymerase activity following infection, but it has only a slight effect on the production of virus in spleen tissue. Thus, the alteration of RNA synthesis is not a result of virus proliferation, but instead may be a manifestation of leukemic erythropoiesis. Normal erythropoiesis, stimulated by erythropoietin administration, produces a similar but transient increase in RNA polymerase activity in spleen nuclei. Erythropoietin administered before, but not after, Friend virus infection results in an enhancement of RNA polymerase activity, as measured 9 days after inoculation. This effect is most simply explained by assuming that there is a common target cell pool for both erythropoietin and Friend virus, and that this pool becomes refractory to the influence of the hormone as a result of the leukemic process.
D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D004920:Erythropoiesis / Q000187:drug effects; D004921:Erythropoietin / Q000494:pharmacology; D005622:Friend murine leukemia virus; D007942:Leukemia, Experimental / Q000201:enzymology*; D051379:Mice; D009929:Organ Size; D012313:RNA / Q000096:biosynthesis; D013154:Spleen / Q000033:anatomy & histology / Q000201:enzymology / Q000648:ultrastructure; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
D004921:Erythropoietin; D003609:Dactinomycin; D012313:RNA; D012321:DNA-Directed RNA Polymerases