Abstract
This work presents direct evidence that the bcl-2 gene is transcriptionally regulated by nuclear factor-kappa B (NF-kappa B) and directly links the TNF-alpha/NF-kappa B signaling pathway with Bcl-2 expression and its pro-survival response in human prostate carcinoma cells. DNase I footprinting, gel retardation and supershift analysis identified a NF-kappa B site in the bcl-2 p2 promoter. In the context of a minimal promoter, this bcl-2 p2 site 1 increased transcription 10-fold in the presence of the p50/p65 expression vectors, comparable to the increment observed with the consensus NF-kappa B site, while for the full p2 promoter region transcriptional activity was increased sixfold by over-expression of NF-kappa B, an effect eliminated by mutating the bcl-2 p2 site 1. The expression of Bcl-2 has been linked to the hormone-resistant phenotype of advanced prostate cancer. Here we show that an increase in the level of expression of Bcl-2 in the human prostate carcinoma cell line LNCaP observed in response to hormone withdrawal is further augmented by TNF-alpha treatment, and this effect is abated by inhibitors of NF-kappa B. Concomitantly, bcl-2 p2 promoter studies in LNCaP cells show a 40-fold increase in promoter activity after stimulation with TNF-alpha in the absence of hormone.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenocarcinoma / genetics*
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Adenocarcinoma / pathology
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Androgens* / pharmacology
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Antineoplastic Agents / pharmacology
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Binding Sites
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Consensus Sequence
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DNA Footprinting
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DNA-Binding Proteins / antagonists & inhibitors
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Dimerization
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Gene Expression Regulation, Neoplastic / physiology*
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Genes, bcl-2*
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Genetic Vectors / genetics
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Humans
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I-kappa B Proteins*
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Male
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Mutagenesis, Site-Directed
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NF-KappaB Inhibitor alpha
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NF-kappa B / antagonists & inhibitors
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NF-kappa B / chemistry
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NF-kappa B / physiology*
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Neoplasms, Hormone-Dependent / genetics*
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Neoplasms, Hormone-Dependent / pathology
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Nitriles*
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Organic Chemicals*
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Peptide Fragments / pharmacology
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Promoter Regions, Genetic / genetics*
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Prostatic Neoplasms / genetics*
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Prostatic Neoplasms / pathology
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Protein Subunits
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Proto-Oncogene Proteins c-bcl-2 / biosynthesis
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Signal Transduction
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Sulfones*
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Transcriptional Activation*
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Transfection
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Tumor Cells, Cultured / drug effects
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Tumor Cells, Cultured / metabolism
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Tumor Necrosis Factor-alpha / pharmacology
Substances
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3-(4-methylphenylsulfonyl)-2-propenenitrile
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Androgens
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Antineoplastic Agents
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DNA-Binding Proteins
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I-kappa B Proteins
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NF-kappa B
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NFKBIA protein, human
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Nitriles
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Organic Chemicals
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Peptide Fragments
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Protein Subunits
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Proto-Oncogene Proteins c-bcl-2
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Sulfones
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Tumor Necrosis Factor-alpha
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NF-KappaB Inhibitor alpha