Protein kinase activity-dependent inhibition of urokinase-type plasminogen activator gene transcription by cyclic AMP in human pre-B lymphoma cell line RC-K8.
We investigated the effects of cAMP on the urokinase-type plasminogen activator (uPA) production in human pre-B lymphoma cell line RC-K8 that is consistently secreting uPA in the conditioned medium. Both Bt2cAMP and PGE1 inhibited the uPA accumulation in a dose-dependent manner. Northern blot analysis and nuclear run-on assay revealed that uPA gene transcription was repressed by Bt2cAMP and the repression was negated by inhibition of de novo protein synthesis by cycloheximide. Pretreatment with H89 (N-[2-(p-bromocinnamyl-amino) ethyl]-5-isoquinoline sulfonamide), a specific cAMP-dependent protein kinase (PKA) inhibitor, strongly inhibited both the PKA activation and the supression of uPA mRNA accumulation induced by cAMP. H85 (N-[2-(N-formyl-p-chlorocinnamyl-amino) ethyl]-5-isoquinoline sulfonamide), which closely resembles H89 in its chemical structure but is not a selective inhibitor of PKA, showed little effect on the regulation of uPA gene regulation by Bt2cAMP. These results suggest that cAMP represses uPA gene transcription in human pre-B lymphoma cells through PKA pathway and in which de novo protein synthesis is required.
Shinbo
M
M
Department of Clinical Laboratory Medicine Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
Niiya
K
K
al-Mokdad
M
M
Hayakawa
Y
Y
Hiraga
K
K
Fujimaki
M
M
Sakuragawa
N
N
D000527:Alprostadil / Q000494:pharmacology; D003994:Bucladesine / Q000031:analogs & derivatives / Q000494:pharmacology; D017077:Culture Media, Conditioned; D000242:Cyclic AMP / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics*
D017077:Culture Media, Conditioned; D012333:RNA, Messenger; D011994:Recombinant Proteins; C002373:monobutyryl cyclic AMP; D003994:Bucladesine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D014568:Urokinase-Type Plasminogen Activator; D000527:Alprostadil; C067551:saruplase