Brefeldin A activates CHOP promoter at the AARE, ERSE and AP-1 elements.
Brefeldin A induces apoptosis in PC-3 and MCF-7 cells at a concentration of 30 ng/ml. RT-PCR analyses showed up-regulation of CHOP/GADD153 and splicing of XBP-1 mRNA in brefeldin A-treated cells. CHOP promoter-luciferase reporter assays demonstrated activation of AARE, ERSE, and AP-1 elements of CHOP promoter by brefeldin A treatment. The activation of these elements was not affected by preincubation of cells with N-acetyl-cysteine (NAC), L: -buthionine-(S,R)-sulfoximine (BSO), and c-Jun N-terminal kinase (JNK) inhibitor (SP600125), suggesting that activation of CHOP promoter by brefeldin A may not involve oxidative stress or JNK signaling pathway. On the other hand, brefeldin A-induced apoptosis was not affected by NAC and BSO pretreatment, but was completely suppressed by JNK inhibitor pretreatment. Our results suggest that although CHOP is up-regulated by brefeldin A, it is not a major mediator of brefeldin A-induced apoptosis.
Kwok
Simon C M
SC
Department of Pathology and Laboratory Medicine, Albert Einstein Medical Center, Philadelphia, PA 19141-3098, USA. kwoks@einstein.edu
Daskal
Ierachmiel
I
D000111:Acetylcysteine / Q000494:pharmacology; D000873:Anthracenes / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D020126:Brefeldin A / Q000494:pharmacology*; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D000071701:Regulatory Factor X Transcription Factors; D020218:Response Elements; D051742:Transcription Factor CHOP / Q000096:biosynthesis*; D014157:Transcription Factors / Q000096:biosynthesis; D015854:Up-Regulation / Q000187:drug effects*; D000071717:X-Box Binding Protein 1
D000873:Anthracenes; C497249:DDIT3 protein, human; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D011500:Protein Synthesis Inhibitors; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors; D000071717:X-Box Binding Protein 1; C000605543:XBP1 protein, human; D051742:Transcription Factor CHOP; C432165:pyrazolanthrone; D020126:Brefeldin A; D019328:Buthionine Sulfoximine; D048031:JNK Mitogen-Activated Protein Kinases; D000111:Acetylcysteine