Inhibition of salvage synthesis of nucleic acid by adenosine 3',5'-cyclic decylphosphoramidate in mastocytoma P-815 cells.
Constant exposure of mastocytoma P-815 cells to adenosine 3',5'-cyclic decylphosphoramidate (1), which is permeable to the cell membrane and resistant to the action of phosphodiesterase, caused a dose-dependent (1 to 50 microM) inhibition in the synthesis of DNA and cell proliferation. Pretreating the cells with compound 1 (20 microM, 4 h) caused considerable inhibition of the incorporation of [3H]thymidine ([3H]TdR) into [3H]deoxythymidine 5'-triphosphate ([3H]dTTP) and that of [14C]hypoxanthine into nucleic acid, but not the synthesis of [14C]dTTP from [U-14C]aspartate. These results indicate that compound 1 preferentially inhibits the salvage synthesis of intracellular nucleotides and nucleic acids. Thymidine kinase, a key enzyme in salvage synthesis of nucleotides, was almost undetectable in cells pretreated with compound 1 at 20 microM for 4 h or at 5 microM for 15 h. On the other hand, compound 1 activated partially purified cAMP-dependent protein kinase A from bovine heart. Judging from these observations, it is likely that compound 1 readily permeates the cell membrane, activates cAMP-dependent protein kinase, then inhibits the salvage synthesis of nucleotides and nucleic acids by inhibiting thymidine kinase, which results in the inhibition of cell growth.
Saito
M
M
Noda Institute for Scientific Research, Chiba, Japan.
Nasu
A
A
Kataoka
S
S
Yamaji
N
N
Ichikawa
A
A
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D004260:DNA Repair / Q000187:drug effects*; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D006801:Humans; D006868:Hydrolysis; D007042:Hypoxanthines / Q000378:metabolism; D012515:Mast-Cell Sarcoma / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology; D009696:Nucleic Acids / Q000096:biosynthesis*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D013937:Thymidine Kinase / Q000378:metabolism; D013942:Thymine Nucleotides / Q000378:metabolism; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; D007042:Hypoxanthines; D009696:Nucleic Acids; D013942:Thymine Nucleotides; C079545:adenosine 3',5'-cyclic decylphosphoramidate; D001224:Aspartic Acid; D000242:Cyclic AMP; D011494:Protein Kinases; D013937:Thymidine Kinase; D010727:Phosphoric Diester Hydrolases; C024157:thymidine 5'-triphosphate