Latest Publications

@article{hyzdalova_transcriptional_2024,

title = {Transcriptional and phenotypical alterations associated with a gradual benzo[a]pyrene-induced transition of human bronchial epithelial cells into mesenchymal-like cells.},

author = {Martina Hýžďalová and Jiřina Procházková and Nicol Straková and Kateřina Pěnčíková and Simona Strapáčová and Jana Slováčková and Simona Kajabová and Helena Líbalová and Jan Topinka and Markéta Kabátková and Jan Vondráček and Steen Mollerup and Miroslav Machala},

doi = {10.1016/j.etap.2024.104424},

issn = {1872-7077 1382-6689},

year  = {2024},

date = {2024-04-01},

journal = {Environmental toxicology and pharmacology},

volume = {107},

pages = {104424},

abstract = {The role of benzo[a]pyrene (BaP), a prominent genotoxic carcinogen and aryl hydrocarbon receptor (AhR) ligand, in tumor progression remains poorly characterized. We investigated the impact of BaP on the process of epithelial-mesenchymal transition (EMT) in normal human bronchial epithelial HBEC-12KT cells. Early morphological changes after 2-week exposure were accompanied with induction of SERPINB2, IL1, CDKN1A/p21 (linked with cell cycle delay) and chemokine CXCL5. After 8-week exposure, induction of cell migration and EMT-related pattern of markers/regulators led to induction of further pro-inflammatory cytokines or non-canonical Wnt pathway ligand WNT5A. This trend of up-regulation of pro-inflammatory genes and non-canonical Wnt pathway constituents was observed also in the BaP-transformed HBEC-12KT-B1 cells. In general, transcriptional effects of BaP differed from those of TGFβ1, a prototypical EMT inducer, or a model non-genotoxic AhR ligand, TCDD. Carcinogenic polycyclic aromatic hydrocarbons could thus induce a unique set of molecular changes linked with EMT and cancer progression.},

note = {Place: Netherlands},

keywords = {*Benzo(a)pyrene/toxicity, *Epithelial Cells/metabolism, 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin, Aryl hydrocarbon receptor, Aryl Hydrocarbon/genetics/metabolism, Benzo[a]pyrene, DNA Damage, Epithelial-Mesenchymal Transition, Human bronchial epithelial cells, Humans, Ligands, Receptors},

pubstate = {published},

tppubtype = {article}

}

@article{vazquez-gomez_aryl_2023,

title = {Aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) play both distinct and common roles in the regulation of colon homeostasis and intestinal carcinogenesis.},

author = {Gerardo Vázquez-Gómez and Jiří Petráš and Zdeněk Dvořák and Jan Vondráček},

doi = {10.1016/j.bcp.2023.115797},

issn = {1873-2968 0006-2952},

year  = {2023},

date = {2023-10-01},

journal = {Biochemical pharmacology},

volume = {216},

pages = {115797},

abstract = {Both aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) belong among key regulators of xenobiotic metabolism in the intestinal tissue. AhR in particular is activated by a wide range of environmental and dietary carcinogens. The data accumulated over the last two decades suggest that both of these transcriptional regulators play a much wider role in the maintenance of gut homeostasis, and that both transcription factors may affect processes linked with intestinal tumorigenesis. Intestinal epithelium is continuously exposed to a wide range of AhR, PXR and dual AhR/PXR ligands formed by intestinal microbiota or originating from diet. Current evidence suggests that specific ligands of both AhR and PXR can protect intestinal epithelium against inflammation and assist in the maintenance of epithelial barrier integrity. AhR, and to a lesser extent also PXR, have been shown to play a protective role against inflammation-induced colon cancer, or, in mouse models employing overactivation of Wnt/β-catenin signaling. In contrast, other evidence suggests that both receptors may contribute to modulation of transformed colon cell behavior, with a potential to promote cancer progression and/or chemoresistance. The review focuses on both overlapping and separate roles of the two receptors in these processes, and on possible implications of their activity within the context of intestinal tissue.},

note = {Place: England},

keywords = {*Receptors, Animals, Aryl hydrocarbon receptor, Aryl Hydrocarbon/genetics/metabolism, Carcinogenesis/genetics/metabolism, Colon cancer, Colon/metabolism, Dietary contaminants, Epithelial barrier, Inflammation, Inflammation/metabolism, Intestine, Mice, Microbial agonists, Pregnane X receptor, Pregnane X Receptor/metabolism, Steroid/metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{simeckova_vitro_2022,

title = {In vitro profiling of toxic effects of environmental polycyclic aromatic hydrocarbons on nuclear receptor signaling, disruption of endogenous metabolism and induction of cellular stress.},

author = {Pavlína Šimečková and Kateřina Pěnčíková and Ondrej Kováč and Josef Slavík and Martina Pařenicová and Jan Vondráček and Miroslav Machala},

doi = {10.1016/j.scitotenv.2021.151967},

issn = {1879-1026 0048-9697},

year  = {2022},

date = {2022-04-01},

journal = {The Science of the total environment},

volume = {815},

pages = {151967},

abstract = {Polycyclic aromatic hydrocarbons (PAHs) may interact with multiple intracellular receptors and related signaling pathways. We comprehensively evaluated the toxicity profiles of six environmentally relevant PAHs differing in structure, genotoxicity and their ability to activate the aryl hydrocarbon receptor (AhR). We focused particularly on their impact on intracellular hormone-, xenobiotic- and lipid-sensing receptors, as well as on cellular stress markers, combining a battery of human reporter gene assays and qRT-PCR evaluation of endogenous gene expression in human hepatocyte-like HepaRG cells, with LC/MS-MS analysis of cellular sphingolipids. The effects of PAHs included: activation of estrogen receptor α (in case of fluoranthene (Fla), pyrene (Pyr), benz[a]anthracene (BaA), benzo[a]pyrene (BaP)), suppression of androgen receptor activity (Fla, BaA, BaP and benzo[k]fluoranthene (BkF)), enhancement of dexamethasone-induced glucocorticoid receptor activity (chrysene (Chry), BaA, and BaP), and potentiation of triiodothyronine-induced thyroid receptor α activity (all tested PAHs). PAHs also induced transcription of endogenous gene targets of constitutive androstane receptor (Fla, Pyr), or repression of target genes of pregnane X receptor and peroxisome proliferator-activated receptor α (in case of the AhR-activating PAHs - Chry, BaA, BaP, and BkF) in HepaRG cells. In the same cell model, the AhR agonists reduced the expression of glucose metabolism genes (PCK1, G6PC and PDK4), and they up-regulated levels of glucosylceramides, together with a concomitant induction of expression of UGCG, glucosylceramide synthesis enzyme. Finally, both BaP and BkF were found to induce expression of early stress and genotoxicity markers: ATF3, EGR1, GDF15, CDKN1A/p21, and GADD45A mRNAs, while BaP alone increased levels of IL-6 mRNA. Overall, whereas low-molecular-weight PAHs exerted significant effects on nuclear receptors (with CYP2B6 induction observed already at nanomolar concentrations), the AhR activation by 4-ring and 5-ring PAHs appeared to be a key mechanism underlying their impact on nuclear receptor signaling, endogenous metabolism and induction of early stress and genotoxicity markers.},

note = {Place: Netherlands},

keywords = {*Polycyclic Aromatic Hydrocarbons/toxicity, Aryl Hydrocarbon/genetics/metabolism, Benzo(a)pyrene, Cellular stress response, Cytoplasmic and Nuclear/genetics, Energy Metabolism, Humans, Nuclear receptors, Polycyclic aromatic hydrocarbons, Receptors, Signal Transduction, Sphingolipids, Xenobiotics},

pubstate = {published},

tppubtype = {article}

}

@article{kabatkova_inhibition_2015,

title = {Inhibition of β-catenin signalling promotes DNA damage elicited by benzo[a]pyrene in a model of human colon cancer cells via CYP1 deregulation.},

author = {Markéta Kabátková and Ondřej Zapletal and Zuzana Tylichová and Jiří Neča and Miroslav Machala and Alena Milcová and Jan Topinka and Alois Kozubík and Jan Vondráček},

doi = {10.1093/mutage/gev019},

issn = {1464-3804 0267-8357},

year  = {2015},

date = {2015-07-01},

journal = {Mutagenesis},

volume = {30},

number = {4},

pages = {565–576},

abstract = {Deregulation of Wnt/β-catenin signalling plays an important role in the pathogenesis of colorectal cancer. Interestingly, this pathway has been recently implicated in transcriptional control of cytochrome P450 (CYP) family 1 enzymes, which are responsible for bioactivation of a number of dietary carcinogens. In the present study, we investigated the impact of inhibition of Wnt/β-catenin pathway on metabolism and genotoxicity of benzo[a]pyrene (BaP), a highly mutagenic polycyclic aromatic hydrocarbon and an efficient ligand of the aryl hydrocarbon receptor, which is known as a primary regulator of CYP1 expression, in cellular models derived from colorectal tumours. We observed that a synthetic inhibitor of β-catenin, JW74, significantly increased formation of BaP-induced DNA adducts in both colorectal adenoma and carcinoma-derived cell lines. Using the short interfering RNA (siRNA) targeting β-catenin, we then found that β-catenin knockdown in HCT116 colon carcinoma cells significantly enhanced formation of covalent DNA adducts by BaP and histone H2AX phosphorylation, as detected by (32)P-postlabelling technique and immunocytochemistry, respectively, and it also induced expression of DNA damage response genes, such as CDKN1A or DDB2. The increased formation of DNA adducts formed by BaP upon β-catenin knockdown corresponded with enhanced production of major BaP metabolites, as well as with an increased expression/activity of CYP1 enzymes. Finally, using siRNA-mediated knockdown of CYP1A1, we confirmed that this enzyme plays a major role in formation of BaP-induced DNA adducts in HCT116 cells. Taken together, the present results indicated that the siRNA-mediated inhibition of β-catenin signalling, which is aberrantly activated in a majority of colorectal cancers, modulated genotoxicity of dietary carcinogen BaP in colon cell model in vitro, via a mechanism involving up-regulation of CYP1 expression and activity.},

note = {Place: England},

keywords = {*DNA Damage, Apoptosis, Aryl Hydrocarbon/genetics/metabolism, Benzo(a)pyrene/*adverse effects, beta Catenin/*antagonists & inhibitors/genetics/metabolism, Blotting, Carcinogens, Cell Proliferation, Colonic Neoplasms/drug therapy/*etiology/*pathology, Cultured, Cytochrome P-450 CYP1A1/antagonists & inhibitors/genetics/*metabolism, DNA Adducts/*adverse effects, Environmental/adverse effects, Enzymologic/*drug effects, Gene Expression Regulation, Humans, Immunoenzyme Techniques, Messenger/genetics, Neoplastic/*drug effects, Real-Time Polymerase Chain Reaction, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Small Interfering/genetics, Tumor Cells, Western},

pubstate = {published},

tppubtype = {article}

}