WK175, a novel antitumor agent, decreases the intracellular nicotinamide adenine dinucleotide concentration and induces the apoptotic cascade in human leukemia cells.
We recently developed a class of novel antitumor agents that elicit a potent growth-inhibitory response in many tumor cells cultured in vitro. WK175, a member of this class, was chosen as a model compound that showed strong in vitro efficacy. WK175 interferes with the intracellular steady-state level of NAD(+), resulting in a decreased cellular NAD(+) concentration. We found that WK175 induces apoptotic cell death without any DNA-damaging effect. The apoptotic death signaling pathway initiated by WK175 was examined in detail: mitochondrial membrane potential, cytochrome c release, caspase 3 activation, caspase 3 and poly(ADP-ribose) polymerase cleavage, and the appearance of a sub-G(1) cell cycle population were determined in time course studies in THP-1 (a human monocytic leukemia cell line) cells. We found activation of this cascade after 24 h of treatment with 10 nM WK175. Induction of apoptosis was prevented by bongkrekic acid, Z-Asp-Glu-Val-Asp-fluoromethylketone, and Z-Leu-Glu-His-Asp-fluoromethylketone, inhibitors of the mitochondrial permeability transition and of caspase 3 and 9, respectively, but not by Ac-Tyr-Val-Ala-Asp-CHO, a specific caspase 1 inhibitor, suggesting the involvement of the permeability transition pore, caspase 3, and caspase 9 in the WK175-induced apoptotic cascade. These results imply that decreased NAD(+) concentration initiates the apoptotic cascade, resulting in the antitumor effect of WK175.
Wosikowski
Katja
K
Pharmacology Department, Klinge Pharma, 81673 Munich, Germany. katja.wosikowski@wilex.de
Mattern
Karin
K
Schemainda
Isabel
I
Hasmann
Max
M
Rattel
Benno
B
Löser
Roland
R
D000970:Antineoplastic Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001865:Bongkrekic Acid / Q000494:pharmacology; D053148:Caspase 3; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D003574:Cytochrome c Group / Q000378:metabolism; D004273:DNA, Neoplasm / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007425:Intracellular Membranes / Q000187:drug effects / Q000502:physiology; D007948:Leukemia, Monocytic, Acute / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D009243:NAD / Q000378:metabolism*; D009930:Organic Chemicals; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D061945:Caspase Inhibitors; D003574:Cytochrome c Group; D004273:DNA, Neoplasm; D004791:Enzyme Inhibitors; D009930:Organic Chemicals; C450199:WK175; D009243:NAD; D001865:Bongkrekic Acid; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases