Alterations of ribonucleotide reductase activity following induction of the nitrite-generating pathway in adenocarcinoma cells.
The murine adenocarcinoma cell line TA 3 synthesized nitrite from L-arginine upon stimulation with gamma-interferon (IFN-gamma) associated with tumor necrosis factor (TNF), and/or bacterial lipopolysaccharide (LPS), but not with IFN-gamma, TNF, or LPS added separately. Induction of the NO2(-)-generating activity caused an inhibition of DNA synthesis in TA 3 cells. This inhibition was prevented by the L-arginine analog N omega-nitro-L-arginine, which inhibited under the same conditions nitrite production by TA 3 cells. The TA 3 M2 subclone, selected for enhanced ribonucleotide reductase activity, was found to be less sensitive than the wild phenotype TA 3 WT to the cytostatic activity mediated by the NO2(-)-generating system. Cytosolic preparations from TA 3 M2 cells treated for 24 or 48 h with IFN-gamma, TNF, and LPS exhibited a reduced ribonucleotide reductase activity, compared to untreated control cells. No reduction in ribonucleotide reductase activity was observed when N omega-nitro-L-arginine was added to treated cells. Addition of L-arginine, NADPH, and tetrahydrobiopterin into cytosolic extracts from 24-h treated TA 3 M2 cells triggered the synthesis of metabolic products from the NO2(-)-generating pathway. This resulted in a dramatic inhibition of the residual ribonucleotide reductase activity present in the extracts. The inhibition was reversed by NG-monomethyl-L-arginine, another specific inhibitor of the NO2(-)-generating activity. No L-arginine-dependent inhibition of ribonucleotide reductase activity was observed using extracts from untreated cells that did not express NO2(-)-generating activity. These results demonstrate that, in an acellular preparation, molecules derived from the NO2(-)-generating pathway exert an inhibitory effect on the ribonucleotide reductase enzyme. This negative action might explain the inhibition of DNA synthesis induced in adenocarcinoma cells by the NO2(-)-generating pathway.
Lepoivre
M
M
Institut de Biochimie, Unité de Recherche Associée au Centre National de la Recherche Scientifique, Université de Paris-Sud, Orsay, France.
Chenais
B
B
Yapo
A
A
Lemaire
G
G
Thelander
L
L
Tenu
J P
JP
D000230:Adenocarcinoma; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008325:Mammary Neoplasms, Experimental; D051379:Mice; D009573:Nitrites / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D012264:Ribonucleotide Reductases / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000201:enzymology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019323:omega-N-Methylarginine
D007375:Interleukin-1; D008070:Lipopolysaccharides; D009573:Nitrites; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003609:Dactinomycin; D019323:omega-N-Methylarginine; D007371:Interferon-gamma; D001120:Arginine; D012264:Ribonucleotide Reductases; D013936:Thymidine