Inhibition of poly(ADP-ribose) polymerase activation attenuates beta-lapachone-induced necrotic cell death in human osteosarcoma cells.
beta-Lapachone, a novel anticancer drug, induces various human carcinoma cells to undergo apoptotic cell death. However, we report here that, in human osteocarcinoma (U2-OS) cells, beta-lapachone induces necrosis rather than apoptosis. beta-Lapachone-induced necrotic cell death in U2-OS cells was characterized by propidium iodide uptake, cytochrome c release, a decreased mitochondrial membrane potential, and ATP depletion. The mitochondrial potential transition (MPT), including the reduction of the mitochondrial transmembrane potential and the release of mitochondrial cytochrome c, occurred in beta-lapachone-treated cells; cotreatment of these cells with cyclosporin A, an inhibitor of MPT pore, failed to prevent necrotic cell death. This indicates that the MPT transition does not play a crucial role in this process. Furthermore, beta-lapachone-induced necrosis was independent of oxidative stress and caspase activation. However, excessive poly(ADP-ribose) polymerase (PARP) activation and subsequent depletion of intracellular NAD(+) and ATP were seen in beta-lapachone-treated U2-OS cells. Cotreatment with a PARP inhibitor, 3-aminobenzamide, decreased beta-lapachone-induced PARP activation and provided significant protection from necrosis by preventing depletion of intracellular NAD(+) and ATP. Taken together, our results suggest that PARP plays an important role in the signaling pathway for beta-lapachone-induced necrosis in U2-OS cells.
Department of Physical Medicine and Rehabilitation, College of Medicine, National Yang-Ming University, Taipei 112, Taiwan, Republic of China.
Tcho-Jen
TJ
Liu
Sheng-Yi
SY
Lin
Yat-Pang
YP
Chau
D000255:Adenosine Triphosphate / Q000378:metabolism; D000972:Antineoplastic Agents, Phytogenic / Q000037:antagonists & inhibitors* / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D001859:Bone Neoplasms / Q000201:enzymology; D002453:Cell Cycle / Q000187:drug effects; D003574:Cytochrome c Group / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D053938:DNA Fragmentation; D004789:Enzyme Activation / Q000187:drug effects; D005434:Flow Cytometry; D016158:Genes, p53 / Q000235:genetics; D006801:Humans; D020287:In Situ Nick-End Labeling; D008564:Membrane Potentials / Q000187:drug effects; D009243:NAD / Q000378:metabolism; D009285:Naphthoquinones / Q000037:antagonists & inhibitors* / Q000633:toxicity; D012516:Osteosarcoma / Q000201:enzymology; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D000972:Antineoplastic Agents, Phytogenic; D003574:Cytochrome c Group; D009285:Naphthoquinones; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D017382:Reactive Oxygen Species; D009243:NAD; C014638:beta-lapachone; D000255:Adenosine Triphosphate; D011065:Poly(ADP-ribose) Polymerases