Enhancement of Metabolic Oxidative Stress-Induced Cytotoxicity by the Thioredoxin Inhibitor 1-Methylpropyl 2-Imidazolyl Disulfide Is Mediated through the ASK1-SEK1-JNK1 Pathway
- 1Department of Surgery, Pharmacology and Cancer Institute, School of Medicine (Y.J.L., J.H.K., J.J.S.), and 2Department of Neurology (J.C.), University of Pittsburgh, Pittsburgh, Pennsylvania
- Dr. Yong J. Lee, Department of Surgery, University of Pittsburgh Cancer Institute, E1056 BST, 200 Lothrop Street, Pittsburgh, PA 15213. E-mail: leeyj{at}msx.upmc.edu
Abstract
We observed previously that glucose deprivation induces cytotoxicity, increases the intracellular levels of hydroperoxide, and activates the stress-activated protein kinase (SEK) pathway. In this study, we hypothesized that 1-methylpropyl 2-imidazolyl disulfide (IV-2), a thioredoxin (TRX) inhibitor, augments glucose deprivation-induced cytotoxicity by promoting c-Jun N-terminal kinase (JNK) activation. Human prostatic carcinoma DU-145 cells were exposed to glucose-free medium containing various concentrations of IV-2 (10–50 μM). Glucose deprivation alone or IV-2 alone induced minimal cytotoxicity within 7 h. However, the combination of glucose deprivation and IV-2 increased cell death in a dose-dependent manner. The cytotoxicity was suppressed by treatment with an antioxidant,N-acetyl-l-cysteine or overexpressing TRX. The combined glucose deprivation and IV-2 treatment also promoted glucose deprivation-induced JNK1 activation by disrupting the interaction between TRX and apoptosis signal-regulating kinase 1 (ASK1). Overexpression of the JNK1 dominant-negative mutant inhibited the activation of the SEK pathway and protected cells from glucose deprivation and IV-2–induced cytotoxicity. Therefore, IV-2 enhances glucose deprivation-induced cytotoxicity by promoting glucose deprivation-induced activation of the ASK1-SEK1-JNK1 pathway.
Footnotes
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This research was supported by National Cancer Institute grant CA48000 and Competitive Medical Research Funds of The University of Pittsburgh Medical Center Health System.
- Abbreviations:
- NAC
- N-acetyl-l-cysteine
- IV-2
- 1-methylpropyl 2-imidazolyl disulfide
- SEK
- stress-activated protein kinase
- TRX
- thioredoxin
- JNK
- c-Jun N-terminal kinase
- NAC
- N-acetyl-l-cysteine
- ASK1
- apoptosis signal-regulating kinase 1
- DMEM
- Dulbecco's modified Eagle medium
- PBS
- phosphate-buffered saline
- PAGE
- polyacrylamide gel electrophoresis
- PMSF
- phenylmethylsulfonyl fluoride
- Ad.TRX
- adenoviral vector containing TRX
- ROS
- reactive oxygen species
- m.o.i.
- multiplicity of infection
- 8-OhdG
- 8-hydroxyl-2′-deoxyguanosine
- 2-dG
- 2-deoxyguanosine
- MEK
- mitogen-activated protein kinase kinase
- MAPK
- mitogen-activated protein kinase
- HPLC-EC
- high-performance liquid chromatography with electrochemical detection
- pfu
- plaque-forming units
- HA
- hemagglutinin
- GST
- glutathioneS-transferase
- Ad.ASK1
- HA-tagged ASK1
- pcDNA3-FLAG-JNK1(APF)
- dominant-negative mutant c-Jun N-terminal kinase 1 cDNA
- HA
- hemagglutinin
-
- Received March 15, 2002.
- Accepted September 3, 2002.
- The American Society for Pharmacology and Experimental Therapeutics
