Latest Publications

@article{prochazkova_adaptive_2018,

title = {Adaptive changes in global gene expression profile of lung carcinoma A549 cells acutely exposed to distinct types of AhR ligands.},

author = {Jiřina Procházková and Simona Strapáčová and Lucie Svržková and Zdeněk Andrysík and Martina Hýžďalová and Eva Hrubá and Kateřina Pěnčíková and Helena Líbalová and Jan Topinka and Jiří Kléma and Joaquín M. Espinosa and Jan Vondráček and Miroslav Machala},

doi = {10.1016/j.toxlet.2018.04.024},

issn = {1879-3169 0378-4274},

year  = {2018},

date = {2018-08-01},

journal = {Toxicology letters},

volume = {292},

pages = {162–174},

abstract = {Exposure to persistent ligands of aryl hydrocarbon receptor (AhR) has been found to cause lung cancer in experimental animals, and lung adenocarcinomas are often associated with enhanced AhR expression and aberrant AhR activation. In order to better understand the action of toxic AhR ligands in lung epithelial cells, we performed global gene expression profiling and analyze TCDD-induced changes in A549 transcriptome, both sensitive and non-sensitive to CH223191 co-treatment. Comparison of our data with results from previously reported microarray and ChIP-seq experiments enabled us to identify candidate genes, which expression status reflects exposure of lung cancer cells to TCDD, and to predict processes, pathways (e.g. ER stress, Wnt/β-cat, IFNɣ, EGFR/Erbb1), putative TFs (e.g. STAT, AP1, E2F1, TCF4), which may be implicated in adaptive response of lung cells to TCDD-induced AhR activation. Importantly, TCDD-like expression fingerprint of selected genes was observed also in A549 cells exposed acutely to both toxic (benzo[a]pyrene, benzo[k]fluoranthene) and endogenous AhR ligands (2-(1H-Indol-3-ylcarbonyl)-4-thiazolecarboxylic acid methyl ester and 6-formylindolo[3,2-b]carbazole). Overall, our results suggest novel cellular candidates, which could help to improve monitoring of AhR-dependent transcriptional activity during acute exposure of lung cells to distinct types of environmental pollutants.},

note = {Place: Netherlands},

keywords = {A549 Cells, Aryl hydrocarbon receptor, Aryl Hydrocarbon/*agonists/metabolism, Azo Compounds/toxicity, Basic Helix-Loop-Helix Transcription Factors/*agonists/metabolism, Benzo(a)pyrene/toxicity, Carbazoles/toxicity, Dioxins, Environmental Pollutants/*toxicity, Fluorenes/toxicity, Gene Expression Profiling/methods, Gene Expression Regulation, Gene Regulatory Networks/drug effects, Genetic/drug effects, Global gene expression profiling, Humans, Indoles/toxicity, Ligands, Lung cancer, Lung Neoplasms/*genetics/metabolism, Neoplastic/*drug effects, Oligonucleotide Array Sequence Analysis, Polychlorinated Dibenzodioxins/toxicity, Pyrazoles/toxicity, Receptors, Signal Transduction/drug effects, Thiazoles/toxicity, Time Factors, Transcription, Transcriptional Activation/drug effects, Transcriptome/*drug effects},

pubstate = {published},

tppubtype = {article}

}

@article{faust_ahr-mediated_2013,

title = {AhR-mediated changes in global gene expression in rat liver progenitor cells.},

author = {Dagmar Faust and Jan Vondráček and Pavel Krčmář and Lenka Smerdová and Jiřina Procházková and Eva Hrubá and Petra Hulinková and Bernd Kaina and Cornelia Dietrich and Miroslav Machala},

doi = {10.1007/s00204-012-0979-z},

issn = {1432-0738 0340-5761},

year  = {2013},

date = {2013-04-01},

journal = {Archives of toxicology},

volume = {87},

number = {4},

pages = {681–698},

abstract = {Although the tumor-promoting effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), coplanar polychlorinated biphenyls (PCBs), and related compounds in liver tissue are primarily attributed to the activation of the aryl hydrocarbon receptor (AhR), the underlying molecular mechanisms are still unclear. Liver progenitor (oval) cells have been suggested to constitute a potential target for hepatocarcinogenic chemicals. To better understand AhR-driven pathways, we analyzed the transcriptional program in response to coplanar PCB 126 in contact-inhibited rat liver progenitor WB-F344 cells using high-density microarrays. After 6-h treatment, we identified 145 significantly deregulated genes considered to be direct AhR-dependent target genes. The number of differentially regulated genes increased to 658 and 968 genes after 24 and 72 h, respectively. Gene ontology analysis revealed that these genes were primarily involved in drug and lipid metabolism, cell cycle and growth control, cancer developmental processes, cell-cell communication, and adhesion. Interestingly, the Wnt and TGF-β signaling pathways, both being involved in developmental and tumorigenic processes, belonged to the most affected pathways. AhR- and ARNT-dependent regulation of selected target genes of interest was then confirmed using TCDD as a model AhR agonist, together with pharmacological inhibition of the AhR and by RNA-interference techniques. We demonstrated AhR-dependent regulation of emerging and novel AhR target genes, such as Fst, Areg, Hbegf, Ctgf, Btg2, and Foxq1. Among them, the transcription factor Foxq1, recently suggested to contribute to tumor promotion and/or progression, was found to be regulated at both mRNA and protein levels by AhR/ARNT activation.},

note = {Place: Germany},

keywords = {Animals, Aryl Hydrocarbon/*genetics/metabolism, Cell Line, Epithelial Cells/drug effects/*metabolism/pathology, Estrogen Antagonists/toxicity, Gene Expression Regulation/drug effects/*genetics, Gene Knockdown Techniques, Liver/drug effects/*metabolism/pathology, Oligonucleotide Array Sequence Analysis, Polychlorinated Biphenyls/toxicity, Rats, Receptors, Stem Cells/drug effects/*metabolism/pathology},

pubstate = {published},

tppubtype = {article}

}

@article{hruba_gene_2011,

title = {Gene expression changes in human prostate carcinoma cells exposed to genotoxic and nongenotoxic aryl hydrocarbon receptor ligands.},

author = {Eva Hrubá and Jan Vondráček and Helena Líbalová and Jan Topinka and Vítězslav Bryja and Karel Souček and Miroslav Machala},

doi = {10.1016/j.toxlet.2011.07.011},

issn = {1879-3169 0378-4274},

year  = {2011},

date = {2011-10-01},

journal = {Toxicology letters},

volume = {206},

number = {2},

pages = {178–188},

abstract = {Carcinogenic polycyclic aromatic hydrocarbons (PAHs) are known as efficient mutagens and ligands of the aryl hydrocarbon receptor (AhR), which has been suggested to play an important role in prostate carcinogenesis. In order to evaluate the complex relationship between the genotoxicity and the AhR-mediated activity of PAHs in prostate cells, we selected benzo[a]pyrene (BaP) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), as model genotoxic and nongenotoxic AhR ligands, respectively, to explore global changes in gene expression in LNCaP cells by microarray analysis. We identified 112 genes that were differentially expressed in cells treated for 24h with BaP, TCDD or both compounds. Our data indicated that the impacts of BaP and TCDD on transcriptome of LNCaP cells significantly overlap, since over 64% of significantly up-regulated genes and 47% of down-regulated genes were similarly affected by both AhR ligands. This suggested that the activation of AhR played a prominent role in the nongenotoxic effects of BaP in the prostate carcinoma cell model LNCaP. Both AhR ligands suppressed expression of genes associated with cell cycle progression, DNA replication, spindle assembly checkpoint or DNA repair, which probably occurred secondary to inhibition of cell cycle progression. In contrast, we identified Wnt5a, an important regulator of prostate cancer progression, to be induced as early as 6h after exposure to both AhR ligands. The AhR ligand-induced Wnt5a upregulation, together with other observed alterations of gene expression, may further contribute to enhanced cell plasticity of prostate carcinoma cells.},

note = {Place: Netherlands},

keywords = {Aryl Hydrocarbon/*agonists, Benzo(a)pyrene/*toxicity, Carcinogens, Carcinoma/metabolism, Cell Cycle/drug effects, Cell Line, DNA Repair/drug effects, DNA Replication/drug effects, Environmental/*toxicity, Gene Expression Profiling, Gene Expression Regulation, Humans, Ligands, Male, Mutagens/*toxicity, Neoplastic/*drug effects, Oligonucleotide Array Sequence Analysis, Polychlorinated Dibenzodioxins/*toxicity, Prostatic Neoplasms/*metabolism, Proto-Oncogene Proteins/genetics/metabolism, Receptors, Spindle Apparatus/drug effects, Time Factors, Tumor, Wnt Proteins/genetics/metabolism, Wnt-5a Protein},

pubstate = {published},

tppubtype = {article}

}