Exp Mol Med.  2000 Dec;32(4):197-203.

Induction of apoptosis in human leukemia cells by 3-deazaadenosine is mediated by caspase-3-like activity

• Kim HS
• Jeong SY
• Lee JH
• Kim BE
• Kim JW
• Jeong SW
• Kim IK

Abstract

3-Deazaadenosine (DZA), one of the potent inhibitors of S-adenosylhomocysteine hydrolase, is known to possess several biological properties including an induction of apoptosis. To evaluate a possibility that DZA may be utilized for the treatment of human leukemia, we studied molecular events of cell death induced by DZA in human leukemia HL-60 and U-937 cells. DZA induced a specific cleavage of poly ADP-ribose polymerase (PARP) and an activation of the cysteine protease caspase-3/CPP32 which is known to cleave PARP. DZA-mediated nuclear DNA-fragmentation was completely blocked in the presence of a universal inhibitor of caspases (z-VAD-fmk) or the specific inhibitor of caspase-3 (z-DEVD-fmk) unlike of cycloheximide (CHX). DNA fragmentation was preceded by the lowering of c-myc mRNA in the DZA treated cells. In addition, DZA-induced apoptosis was blocked by pretreatment with adenosine transporter inhibitors such as nitrobenzylthioinosine (NBTI) and dipyridamole (DPD). Taken together, these results demonstrate that DZA-induced apoptosis initiated through an active transport of DZA into human leukemia cells, is dependent on the caspase-3-like activity without de novo synthesis of proteins and possibly involves c-myc down-regulation.

Keyword

3-deazaadenosine; leukemia; apoptosis; caspase; c-myc

MeSH Terms

Adenosine/metabolism
*Apoptosis
Biological Transport, Active
Carrier Proteins/metabolism
Caspases/*metabolism
Down-Regulation
Enzyme Activation
Genes, myc
HL-60 Cells
Human
Leukemia, Promyelocytic, Acute/*drug therapy
Thioinosine/*analogs & derivatives/pharmacology
Transcription Factors/genetics
Tubercidin/*pharmacology
U937 Cells