Involvement of activating transcription factors JNK, NF-kappaB, and AP-1 in apoptosis induced by pyrrolidine dithiocarbamate/Cu complex.
Pyrrolidine dithiocarbamate (PDTC) is a metal chelator. Biologically, slight toxic affects EC50, 100+/-5.9 microM are observed when added to cultured HL-60 cells. CuCl2 at a physiological concentration (1 microM), but not FeCl2, Pb potentiated the cytotoxic effect of PDTC by 700 fold (EC50, 0.14+/-0.02 microM). Furthermore, results indicated that the PDTC/Cu complex induced an apoptotic process, evidenced by apoptotic bodies, DNA ladder and hypodiploidy cells. Additional studies showed that PDTC/Cu complex significantly decreased mitochondrial membrane potential, increased cytochrome c release, and reactive oxygen species production, and depleted reduced non-protein thiols in a time-dependent manner. Following oxidative stress, the PDTC/Cu complex sequentially activated JNK, NF-kappaB and AP-1 signaling pathways while IkappaB kinase activity was enhanced. The apoptotic process was eventually induced by caspase 3 activation and PARP degradation. The non-permeable copper-specific chelator-bathocuproine disulfonate (BCPS) and vitamin C were able to inhibit apoptosis and the elevation of intracellular Cu. Based on these findings; we conclude that PDTC/Cu complex-induced apoptosis is mediated by activation of JNK, NF-kappaB, AP-1 and caspase 3. Due to its high potency, PDTC may be useful as a therapeutic anti-cancer drug.
Chen
Sung-Ho
SH
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Lin
Jen-Kun
JK
Liang
Yu-Chih
YC
Pan
Min-Hsiung
MH
Liu
Shing-Hwa
SH
Lin-Shiau
Shoei-Yn
SY
D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000494:pharmacology*; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D024202:Electrophoretic Mobility Shift Assay; D005434:Flow Cytometry; D005609:Free Radicals / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000187:drug effects; D016328:NF-kappa B / Q000187:drug effects / Q000502:physiology*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology*; D013054:Spectrophotometry, Atomic; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013859:Thiocarbamates / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000187:drug effects / Q000502:physiology*
D005609:Free Radicals; D016328:NF-kappa B; D011759:Pyrrolidines; D013438:Sulfhydryl Compounds; D013859:Thiocarbamates; D018808:Transcription Factor AP-1; C020972:pyrrolidine dithiocarbamic acid; D003300:Copper; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D051550:I-kappa B Kinase; D048031:JNK Mitogen-Activated Protein Kinases; D053148:Caspase 3