Interaction of cytocidal drugs and the inhibition of caspase-3 by 3-nitrosobenzamide.
The effect of 3-nitrosobenzamide (NOBA) on the etoposide, staurosporine and dexamethason induced rapid (4-6 hr), caspase-dependent apoptosis was investigated in thymocytes and lymphoma cells by flow cytometric assay of DNA fragmentation. When NOBA (ED(50) = 4 microM) was added to these cell systems, the rapid onset of apoptosis was prevented. Such apparent protection by NOBA was related to the inactivation of caspase-3, by s-nitrosylation of 1.3 mol -SH per enzyme molecule out of 7 -SH groups. Since NOBA by itself induces DNA fragmentation within 18 hr in lymphoma cells, our results indicate that at least two active cell death pathways exist with apparent dissimilar kinetics and molecular mechanisms.
Mihalik
R
R
I. Institute of Pathology and Experimental Cancer Research, Semmelweis University of Medicine, Budapest, Hungary.
Bauer
P
P
Peták
I
I
Krajcsi
P
P
Marton
A
A
Kun
E
E
Kopper
L
L
D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D053148:Caspase 3; D061945:Caspase Inhibitors; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D053938:DNA Fragmentation; D003907:Dexamethasone / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors; D005047:Etoposide / Q000633:toxicity*; D005434:Flow Cytometry; D006801:Humans; D007700:Kinetics; D016393:Lymphoma, B-Cell; D051379:Mice; D008807:Mice, Inbred BALB C; D009603:Nitroso Compounds / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014407:Tumor Cells, Cultured
D001549:Benzamides; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D004792:Enzyme Precursors; D009603:Nitroso Compounds; D011994:Recombinant Proteins; D005047:Etoposide; D003907:Dexamethasone; C076039:3-nitrosobenzamide; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3