The aryl hydrocarbon receptor-dependent deregulation of cell cycle control induced by polycyclic aromatic hydrocarbons in rat liver epithelial cells
Language English Country Netherlands Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
17141280
DOI
10.1016/j.mrfmmm.2006.10.004
PII: S0027-5107(06)00309-5
Knihovny.cz E-resources
- MeSH
- Apoptosis drug effects MeSH
- Benz(a)Anthracenes toxicity MeSH
- Benzo(a)pyrene toxicity MeSH
- Cell Line MeSH
- Cell Cycle drug effects physiology MeSH
- Cyclin A metabolism MeSH
- Cyclin-Dependent Kinase 2 metabolism MeSH
- Cytochrome P-450 CYP1A1 genetics MeSH
- Epithelial Cells cytology drug effects metabolism MeSH
- Gene Expression drug effects MeSH
- Fluorenes toxicity MeSH
- Hepatocytes cytology drug effects metabolism MeSH
- Rats MeSH
- RNA, Small Interfering genetics MeSH
- RNA, Messenger genetics metabolism MeSH
- Multiprotein Complexes MeSH
- Mutation MeSH
- Mutagens toxicity MeSH
- Polycyclic Aromatic Hydrocarbons toxicity MeSH
- Cell Proliferation drug effects MeSH
- Cell Cycle Proteins metabolism MeSH
- Receptors, Aryl Hydrocarbon antagonists & inhibitors genetics metabolism MeSH
- Base Sequence MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- benz(a)anthracene MeSH Browser
- Benz(a)Anthracenes MeSH
- benzo(b)fluoranthene MeSH Browser
- Benzo(a)pyrene MeSH
- Cdk2 protein, rat MeSH Browser
- Cyclin A MeSH
- Cyclin-Dependent Kinase 2 MeSH
- Cytochrome P-450 CYP1A1 MeSH
- Fluorenes MeSH
- RNA, Small Interfering MeSH
- RNA, Messenger MeSH
- Multiprotein Complexes MeSH
- Mutagens MeSH
- Polycyclic Aromatic Hydrocarbons MeSH
- Cell Cycle Proteins MeSH
- Receptors, Aryl Hydrocarbon MeSH
Disruption of cell proliferation control by polycyclic aromatic hydrocarbons (PAHs) may contribute to their carcinogenicity. We investigated role of the aryl hydrocarbon receptor (AhR) in disruption of contact inhibition in rat liver epithelial WB-F344 'stem-like' cells, induced by the weakly mutagenic benz[a]anthracene (BaA), benzo[b]fluoranthene (BbF) and by the strongly mutagenic benzo[a]pyrene (BaP). There were significant differences between the effects of BaA and BbF, and those of the strongly genotoxic BaP. Both BaA and BbF increased percentage of cells entering S-phase and cell numbers, associated with an increased expression of Cyclin A and Cyclin A/cdk2 complex activity. Their effects were significantly reduced in cells expressing a dominant-negative AhR mutant (dnAhR). Roscovitine, a chemical inhibitor of cdk2, abolished the induction of cell proliferation by BbF. However, neither BaA nor BbF modulated expression of the principal cdk inhibitor involved in maintenance of contact inhibition, p27(Kip1), or pRb phosphorylation. The strongly mutagenic BaP induced apoptosis, a decrease in total cell numbers and significantly higher percentage of cells entering S-phase than either BaA or BbF. Given that BaP induced high levels of Cyclin A/cdk2 activity, downregulation of p27(Kip1) and hyperphosphorylation of pRb, the accumulation of cells in S-phase was probably due to cell proliferation, although S-phase arrest due to blocked replication forks can not be excluded. Both types of effects of BaP were significantly attenuated in dnAhR cells. Transfection of WB-F344 cells with siRNA targeted against AhR decreased induction of Cyclin A induced by BbF or BaP, further supporting the role of AhR in proliferative effects of PAHs. This suggest that activation of AhR plays a significant role both in disruption of contact inhibition by weakly mutagenic PAHs and in genotoxic effects of BaP possibly leading to enhanced cell proliferation. Thus, PAHs may increase proliferative rate and the likelihood of fixation of mutations.
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