Abstract
This study was performed to prove our hypothesis that the metabolite(s) of polycyclic aromatic hydrocarbons (PAHs) caused the activation or phosphorylation of p53 via DNA damage to suppress the liver X receptor (LXR)-mediated signal transductions as a probably more direct mechanism. We found that LXR-mediated trans-activation was inhibited by 3-methylchoranthrene (MC) and doxorubicin (Dox) in HepG2 cells carrying wild-type p53, but not in Hep3B cells possessing mutant p53. The exogenous expression of wild-type p53 suppressed the LXR-mediated trans-activation in Hep3B cells. The expression of mRNA for ATP binding cassette A1 was suppressed by MC and Dox in HepG2 cells. The protein expression of retinoid X receptor (RXR), a partner of LXR to form a heterodimer, was suppressed by MC and Dox in HepG2 cells.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Antibiotics, Antineoplastic / metabolism
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Antibiotics, Antineoplastic / pharmacology*
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Cell Line, Tumor
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DNA Damage / drug effects
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DNA-Binding Proteins / metabolism*
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Dimerization
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Doxorubicin / metabolism
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Doxorubicin / pharmacology*
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Gene Expression Regulation, Neoplastic / drug effects
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Gene Expression Regulation, Neoplastic / genetics
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Humans
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Liver X Receptors
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Methylcholanthrene / metabolism
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Methylcholanthrene / pharmacology
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Mutation
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Orphan Nuclear Receptors
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Phosphorylation / drug effects
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Protein Processing, Post-Translational / drug effects*
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Receptors, Cytoplasmic and Nuclear / metabolism*
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Retinoid X Receptors / biosynthesis
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Signal Transduction / drug effects
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Transcriptional Activation / drug effects*
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Tumor Suppressor Protein p53 / genetics
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Tumor Suppressor Protein p53 / metabolism*
Substances
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Antibiotics, Antineoplastic
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DNA-Binding Proteins
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Liver X Receptors
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Orphan Nuclear Receptors
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Receptors, Cytoplasmic and Nuclear
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Retinoid X Receptors
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Tumor Suppressor Protein p53
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Methylcholanthrene
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Doxorubicin