Abstract
In diverse cell types, NF-kappaB transcription factors have been shown to have a role in regulating the apoptotic program, either as essential for the induction of apoptosis or, perhaps more commonly, as blockers of apoptosis. We investigated the role of NF-kappaB activation in the TNF-alpha-mediated apoptosis in lung cancer cells. TNF-alpha-resistant NCI-H157 cells became sensitized to TNF-alpha by prior treatment with cycloheximide, suggesting the presence of newly synthesized antiapoptotic protein(s). We next evaluated whether the transcription of antiapoptotic protein(s) depends on the activation of NF-kappaB. NF-kappaB activation was blocked by either adenovirus-mediated overexpression of IkappaBalpha superrepressor or pretreatment with proteasome inhibitor, MG132. Both methods of blocking NF-kappaB activation enhanced TNF-alpha-induced apoptosis in NCI-H157 cells. These results suggest that NF-kappaB activation confers resistance to TNF-alpha-mediated apoptosis in lung cancer cells.
Copyright 2000 Academic Press.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenoviridae / genetics
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Apoptosis / drug effects*
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Cycloheximide / pharmacology
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Cysteine Endopeptidases / metabolism
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism
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Drug Resistance, Neoplasm
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Enzyme Inhibitors / pharmacology
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Humans
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I-kappa B Proteins*
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Lung Neoplasms / enzymology
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Lung Neoplasms / genetics
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Lung Neoplasms / metabolism*
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Lung Neoplasms / pathology*
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Multienzyme Complexes / metabolism
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NF-KappaB Inhibitor alpha
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NF-kappa B / antagonists & inhibitors
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NF-kappa B / metabolism*
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Neoplasm Proteins / biosynthesis
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Proteasome Endopeptidase Complex
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Protein Processing, Post-Translational / drug effects
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Tumor Cells, Cultured
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Tumor Necrosis Factor-alpha / agonists
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Tumor Necrosis Factor-alpha / antagonists & inhibitors*
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Tumor Necrosis Factor-alpha / pharmacology*
Substances
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DNA-Binding Proteins
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Enzyme Inhibitors
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I-kappa B Proteins
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Multienzyme Complexes
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NF-kappa B
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NFKBIA protein, human
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Neoplasm Proteins
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Tumor Necrosis Factor-alpha
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NF-KappaB Inhibitor alpha
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Cycloheximide
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Cysteine Endopeptidases
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Proteasome Endopeptidase Complex