Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants that interact in a complex manner with both the aryl hydrocarbon receptor (AhR) and estrogen receptors (ER). Their potential endocrine-disrupting activities may depend on both inhibitory AhR-ER cross-talk and on AhR-dependent metabolic production of estrogenic PAH metabolites. Here, we analyzed the impact of AhR on estrogen-like effects of PAHs, such as benzo[a]pyrene (BaP), in particular, on control of cell cycle progression/cell proliferation. Using AhR knockout variant of estrogen-sensitive human breast cancer MCF-7 cells (MCF-7 AhRKO cells), we observed that the AhR-dependent control of cytochrome P450 family 1 (CYP1) expression played a major role in formation of estrogenic BaP metabolites, most notably 3-OH-BaP, which contributed to the ER-dependent induction of cell cycle progression/cell proliferation. Both BaP metabolism and the BaP-induced S-phase transition/cell proliferation were inhibited in MCF-7 AhRKO cells, whereas these cells remained sensitive towards both endogenous estrogen 17β-estradiol or hydroxylated BaP metabolites. BaP was found to increase the activity of ER-dependent luciferase reporter gene in wild-type MCF-7 cells; however, unlike its hydroxylated metabolite, BaP failed to stimulate luciferase activity in MCF-7 AhRKO cells. Similarly, estrogen-like effects of other known estrogenic PAHs, such as benz[a]anthracene or 3-methylcholanthrene, were diminished in MCF-7 AhRKO cells. Ectopic expression of human CYP1A1 and CYP1B1 enzymes partly restored both BaP metabolism and its effects on cell proliferation. Taken together, our data suggest that the AhR-dependent metabolism of PAHs contributes significantly to the impact of PAHs on cell proliferation in estrogen-sensitive cells.

• MeSH
• buněčné kultury MeSH
• buněčný cyklus účinky léků   genetika   MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• cytochrom P450 CYP1B1 genetika   metabolismus   MeSH
• endokrinní disruptory metabolismus   toxicita   MeSH
• exprese genu účinky léků   MeSH
• genetické vektory MeSH
• genový knockdown MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• plazmidy MeSH
• polycyklické aromatické uhlovodíky metabolismus   toxicita   MeSH
• proliferace buněk účinky léků   genetika   MeSH
• receptory aromatických uhlovodíků genetika   metabolismus   MeSH
• receptory pro estrogeny genetika   metabolismus   MeSH
• reportérové geny MeSH
• transfekce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Stable cell lines obtained by spontaneous immortalization might represent early stages of malignant transformation and be useful experimental models for studies of mechanisms of cancer development. The FHC (fetal human cells) cell line has been established from normal fetal colonic mucosa. Detailed characterization of this cell line and mechanism of spontaneously acquired immortality have not been described yet. Therefore, we characterized the FHC cell line in terms of its tumorigenicity, cytogenetics, and TP53 gene mutation analysis. FHC cells displayed capability for anchorage-independent growth in semisolid media in vitro and formed solid tumors after transplantation into SCID (severe combined immunodeficiency) mice. This tumorigenic phenotype was associated with hypotriploidy and chromosome number ranging from 66 to 69. Results of comparative genetic hybridization arrays showed that most chromosomes included regions of copy number gains or losses. Region 8q23 approximately 8q24.3 (containing, e.g., MYC proto-oncogene) was present in more than 20 copies per nucleus. Moreover, we identified mutation of TP53 gene in codon 273; triplet CGT coding Arg was changed to CAG coding His. Expression of Pro codon 72 polymorphic variant of p53 was also detected. Mutation of TP53 gene was associated with abolished induction of p21(Waf1/Cip1) and MDM-2 proteins and resistance to apoptosis after genotoxic treatment. Because of their origin from normal fetal colon and their relative resistance to the induction of apoptosis, FHC cells can be considered a valuable experimental model for various studies.

• MeSH
• apoptóza fyziologie   MeSH
• buněčná adheze fyziologie   MeSH
• buňky - růstové procesy fyziologie   MeSH
• cytogenetické vyšetření metody   MeSH
• fenotyp MeSH
• geny p53 MeSH
• HCT116 buňky MeSH
• hybridizace in situ fluorescenční MeSH
• karcinoembryonální antigen metabolismus   MeSH
• karyotypizace MeSH
• keratiny metabolismus   MeSH
• kolon cytologie   metabolismus   fyziologie   MeSH
• lidé MeSH
• mutační analýza DNA metody   MeSH
• myši SCID MeSH
• myši MeSH
• nádorová transformace buněk genetika   patologie   MeSH
• nádory tračníku genetika   patologie   MeSH
• plod cytologie   MeSH
• poškození DNA MeSH
• signální transdukce MeSH
• srovnávací genomová hybridizace MeSH
• transformované buněčné linie MeSH
• transplantace nádorů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH