RRR-alpha-tocopheryl succinate induction of prolonged activation of c-jun amino-terminal kinase and c-jun during induction of apoptosis in human MDA-MB-435 breast cancer cells.
We have demonstrated that RRR-alpha-tocopheryl succinate (10 microg/mL vitamin E succinate (VES) treatment of estrogen receptor-negative MDA-MB-435 human breast cancer cells induces 9, 19, 51, and 72% apoptotic cells on days 1-4, respectively, after treatment, which involves transforming growth factor-beta signaling. Here, we show that VES-triggered apoptosis of MDA-MB-435 cells induced prolonged elevated expression of c-jun mRNA and protein (neither of which was caused by major increases in stability) and also induced enhanced activator protein-1 (AP-1) binding to the consensus DNA oligomer. Furthermore, VES treatments resulted in increased AP-1 transactivation activity, as measured with an AP-1 promoter/luciferase reporter construct and by the measurement of increased mRNA expression of the AP-1-dependent endogenous gene collagenase. Evidence of VES-induced involvement of the c-jun amino-terminal kinase in these AP-1-dependent events was suggested by data showing prolonged activity of this kinase, as measured by a kinase assay using glutathione S-transferase-c-jun as the substrate. The c-jun-dependent transcriptional activity was verified by cotransfection of a chimeric transcription factor having a galactose 4 DNA-binding domain coupled with the transactivation domain of c-jun plus the reporter plasmid 5X GAL4-luciferase. MDA-MB-435 cells infected with an adenovirus expression vector containing the TAM-67 sequence for dominant/negative-acting mutant c-jun or transiently transfected with c-jun antisense exhibited a 50-77% reduction in VES-mediated apoptosis as compared with control adenovirus-infected or control sense oligomer-transfected cells.
Yu
W
W
Department of Zoology, The University of Texas at Austin, 78712-1097, USA.
Simmons-Menchaca
M
M
You
H
H
Brown
P
P
Birrer
M J
MJ
Sanders
B G
BG
Kline
K
K
D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D016384:Consensus Sequence; D004273:DNA, Neoplasm / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D009154:Mutation; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010766:Phosphorylation; D011494:Protein Kinases / Q000096:biosynthesis / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013237:Stereoisomerism; D024505:Tocopherols; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015533:Transcriptional Activation / Q000187:drug effects; D014407:Tumor Cells, Cultured; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology
D004273:DNA, Neoplasm; D016376:Oligonucleotides, Antisense; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014810:Vitamin E; D011494:Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D024505:Tocopherols