Latest Publications

@article{mickova_skp2_2021,

title = {Skp2 and Slug Are Coexpressed in Aggressive Prostate Cancer and Inhibited by Neddylation Blockade.},

author = {Alena Mickova and Gvantsa Kharaishvili and Daniela Kurfurstova and Mariam Gachechiladze and Milan Kral and Ondrej Vacek and Barbora Pokryvkova and Martin Mistrik and Karel Soucek and Jan Bouchal},

doi = {10.3390/ijms22062844},

issn = {1422-0067},

year  = {2021},

date = {2021-03-01},

journal = {International journal of molecular sciences},

volume = {22},

number = {6},

abstract = {Prostate cancer (PCa) is the second leading cause of cancer-related deaths in men in Western countries, and there is still an urgent need for a better understanding of PCa progression to inspire new treatment strategies. Skp2 is a substrate-recruiting component of the E3 ubiquitin ligase complex, whose activity is regulated through neddylation. Slug is a transcriptional repressor involved in the epithelial-to-mesenchymal transition, which may contribute to therapy resistance. Although Skp2 has previously been associated with a mesenchymal phenotype and prostate cancer progression, the relationship with Slug deserves further elucidation. We have previously shown that a high Gleason score (≥8) is associated with higher Skp2 and lower E-cadherin expression. In this study, significantly increased expression of Skp2, AR, and Slug, along with E-cadherin downregulation, was observed in primary prostate cancer in patients who already had lymph node metastases. Skp2 was slightly correlated with Slug and AR in the whole cohort (Rs 0.32 and 0.37, respectively), which was enhanced for both proteins in patients with high Gleason scores (Rs 0.56 and 0.53, respectively) and, in the case of Slug, also in patients with metastasis to lymph nodes (Rs 0.56). Coexpression of Skp2 and Slug was confirmed in prostate cancer tissues by multiplex immunohistochemistry and confocal microscopy. The same relationship between these two proteins was observed in three sets of prostate epithelial cell lines (PC3, DU145, and E2) and their mesenchymal counterparts. Chemical inhibition of Skp2, but not RNA interference, modestly decreased Slug protein in PC3 and its docetaxel-resistant subline PC3 DR12. Importantly, chemical inhibition of Skp2 by MLN4924 upregulated p27 and decreased Slug expression in PC3, PC3 DR12, and LAPC4 cells. Novel treatment strategies targeting Skp2 and Slug by the neddylation blockade may be promising in advanced prostate cancer, as recently documented for other aggressive solid tumors.},

note = {Place: Switzerland},

keywords = {*Protein Processing, Androgen/genetics/metabolism, Antigens, Antineoplastic Agents/pharmacology, Cadherins/genetics/metabolism, CD/genetics/metabolism, Cell Line, Cell Survival/drug effects, Cyclin-Dependent Kinase Inhibitor p27/genetics/metabolism, Cyclopentanes/pharmacology, Docetaxel/pharmacology, Epithelial-Mesenchymal Transition/genetics, Gene Expression Regulation, Humans, Immunohistochemistry, Lymphatic Metastasis, Male, multiplex, NEDD8 Protein/*genetics/metabolism, neddylation, Neoplasm Grading, Neoplastic, PC-3 Cells, Post-Translational, Prostate cancer, Prostate/metabolism/pathology, Prostatic Neoplasms/*genetics/metabolism/pathology, Pyrimidines/pharmacology, Receptors, RNA, S-Phase Kinase-Associated Proteins/antagonists & inhibitors/*genetics/metabolism, Skp2 (S-phase kinase-associated protein 2), Slug, Small Interfering/genetics/metabolism, Snail Family Transcription Factors/*genetics/metabolism, Tumor},

pubstate = {published},

tppubtype = {article}

}

@article{svobodova_2378-tetrachlorodibenzo-p-dioxin_2019,

title = {2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) Disrupts Control of Cell Proliferation and Apoptosis in a Human Model of Adult Liver Progenitors.},

author = {Jana Svobodová and Jiřina Procházková and Markéta Kabátková and Martin Krkoška and Lenka Šmerdová and Helena Líbalová and Jan Topinka and Jiří Kléma and Alois Kozubík and Miroslav Machala and Jan Vondráček},

doi = {10.1093/toxsci/kfz202},

issn = {1096-0929},

year  = {2019},

date = {2019-12-01},

journal = {Toxicological sciences : an official journal of the Society of Toxicology},

volume = {172},

number = {2},

pages = {368–384},

abstract = {The aryl hydrocarbon receptor (AhR) activation has been shown to alter proliferation, apoptosis, or differentiation of adult rat liver progenitors. Here, we investigated the impact of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated AhR activation on a human model of bipotent liver progenitors, undifferentiated HepaRG cells. We used both intact undifferentiated HepaRG cells, and the cells with silenced Hippo pathway effectors, yes-associated protein 1 (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), which play key role(s) in tissue-specific progenitor cell self-renewal and expansion, such as in liver, cardiac, or respiratory progenitors. TCDD induced cell proliferation in confluent undifferentiated HepaRG cells; however, following YAP, and, in particular, double YAP/TAZ knockdown, TCDD promoted induction of apoptosis. These results suggested that, unlike in mature hepatocytes, or hepatocyte-like cells, activation of the AhR may sensitize undifferentiated HepaRG cells to apoptotic stimuli. Induction of apoptosis in cells with silenced YAP/TAZ was associated with upregulation of death ligand TRAIL, and seemed to involve both extrinsic and mitochondrial apoptosis pathways. Global gene expression analysis further suggested that TCDD significantly altered expression of constituents and/or transcriptional targets of signaling pathways participating in control of expansion or differentiation of liver progenitors, including EGFR, Wnt/β-catenin, or tumor growth factor-β signaling pathways. TCDD significantly upregulated cytosolic proapoptotic protein BMF (Bcl-2 modifying factor) in HepaRG cells, which could be linked with an enhanced sensitivity of TCDD-treated cells to apoptosis. Our results suggest that, in addition to promotion of cell proliferation and alteration of signaling pathways controlling expansion of human adult liver progenitors, AhR ligands may also sensitize human liver progenitor cells to apoptosis.},

note = {Place: United States},

keywords = {*Models, Adaptor Proteins, Apoptosis, Apoptosis/*drug effects/genetics, Aryl hydrocarbon receptor, Aryl Hydrocarbon/metabolism, Biological, Cell Line, Cell Proliferation, Cell Proliferation/*drug effects/genetics, Gene Expression/drug effects, HepaRG cells, Hippo signaling, Humans, Liver/*drug effects/pathology, Polychlorinated Dibenzodioxins/*toxicity, Receptors, RNA, Signal Transducing/genetics, Signal Transduction, Small Interfering/genetics, Stem Cells/*drug effects/pathology, Trans-Activators/genetics, Transcription Factors/genetics, Transcriptional Coactivator with PDZ-Binding Motif Proteins, Transfection, YAP-Signaling Proteins},

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}

}

@article{uhlik_bacterial_2014,

title = {Bacterial acquisition of hexachlorobenzene-derived carbon in contaminated soil.},

author = {Ondrej Uhlik and Michal Strejcek and Jan Vondracek and Lucie Musilova and Jakub Ridl and Petra Lovecka and Tomas Macek},

doi = {10.1016/j.chemosphere.2014.04.110},

issn = {1879-1298 0045-6535},

year  = {2014},

date = {2014-10-01},

journal = {Chemosphere},

volume = {113},

pages = {141–145},

abstract = {Pesticides are a class of xenobiotics intentionally released into the environment. Hexachlorobenzene (HCB) was used as a fungicide from 1945, leaving behind many contaminated sites. Very few studies have examined the biodegradation of HCB or the fate of HCB-derived carbon. Here we report that certain bacterial populations are capable of deriving carbon from HCB in contaminated soil under aerobic conditions. These populations are primarily Proteobacteria, including Methylobacterium and Pseudomonas, which predominated as detected by stable isotope probing (SIP) and 16S rRNA gene amplicon pyrosequencing. Due to the nature of SIP, which can be used as a functional method solely for assimilatory processes, it is not possible to elucidate whether these populations metabolized directly HCB or intermediates of its metabolism produced by different populations. The possibility exists that HCB is degraded via the formation of pentachlorophenol (PCP), which is further mineralized. With this in mind, we designed primers to amplify PCP 4-monooxygenase-coding sequences based on the available pcpB gene sequence from Methylobacterium radiotolerans JCM 2831. Based on 16S rRNA gene analysis, organisms closely related to this strain were detected in (13)C-labeled DNA. Using the designed primers, we were able to amplify pcpB genes in both total community DNA and (13)C-DNA. This indicates that HCB might be transformed into PCP before it gets assimilated. In summary, this study is the first report on which bacterial populations benefit from carbon originating in the pesticide HCB in a contaminated soil.},

note = {Place: England},

keywords = {*Soil Microbiology, 16S rRNA genes, 16S/genetics, Amplicon pyrosequencing, Biodegradation, Bioremediation, Carbon Isotopes/metabolism, Czech Republic, DNA, DNA Primers, Environmental, Hexachlorobenzene/chemistry/*metabolism, Isotope Labeling, Methylobacterium/*metabolism, Mixed Function Oxygenases/metabolism, Molecular Structure, Pentachlorophenol 4-monooxygenase, Pentachlorophenol/chemistry/metabolism, Pesticides, Pseudomonas/*metabolism, Real-Time Polymerase Chain Reaction, Ribosomal, RNA, Sequence Analysis, Soil Pollutants/*metabolism, Stable isotope probing},

pubstate = {published},

tppubtype = {article}

}

@article{smerdova_inflammatory_2013,

title = {Inflammatory mediators accelerate metabolism of benzo[a]pyrene in rat alveolar type II cells: the role of enhanced cytochrome P450 1B1 expression.},

author = {Lenka Smerdová and Jiří Neča and Jana Svobodová and Jan Topinka and Jana Schmuczerová and Alois Kozubík and Miroslav Machala and Jan Vondráček},

doi = {10.1016/j.tox.2013.09.001},

issn = {1879-3185 0300-483X},

year  = {2013},

date = {2013-12-01},

journal = {Toxicology},

volume = {314},

number = {1},

pages = {30–38},

abstract = {Long-term deregulated inflammation represents one of the key factors contributing to lung cancer etiology. Previously, we have observed that tumor necrosis factor-α (TNF-α), a major pro-inflammatory cytokine, enhances genotoxicity of benzo[a]pyrene (B[a]P), a highly carcinogenic polycyclic aromatic hydrocarbon, in rat lung epithelial RLE-6TN cells, a model of alveolar type II cells. Therefore, we analyzed B[a]P metabolism in RLE-6TN cells under inflammatory conditions, simulated using either recombinant TNF-α, or a mixture of inflammatory mediators derived from activated alveolar macrophage cell line. Inflammatory conditions significantly accelerated BaP metabolism, as evidenced by decreased levels of both parent B[a]P and its metabolites. TNF-α altered production of the metabolites associated with dihydrodiol-epoxide and radical cation pathways of B[a]P metabolism, especially B[a]P-dihydrodiols, and B[a]P-diones. We then evaluated the role of cytochrome P450 1B1 (CYP1B1), which is strongly up-regulated in cells treated with B[a]P under inflammatory conditions, in the observed effects. The siRNA-mediated CYP1B1 knock-down increased levels of B[a]P and reduced formation of stable DNA adducts, thus confirming the essential role of CYP1B1 in B[a]P metabolism under inflammatory conditions. TNF-α also reduced expression of aldo-keto reductase 1C14, which may compete with CYP1B1 for B[a]P-7,8-dihydrodiol and divert it from the formation of ultimate B[a]P dihydrodiol epoxide. Together, the present data suggests that the CYP1B1-catalyzed metabolism of polycyclic aromatic hydrocarbons might contribute to their enhanced bioactivation and genotoxic effects under inflammatory conditions.},

note = {Place: Ireland},

keywords = {Animals, Aryl Hydrocarbon Hydroxylases/*biosynthesis/genetics, ATP Binding Cassette Transporter, Benzo(a)pyrene/*metabolism, Blotting, Cell Line, Conditioned, Culture Media, CYP1B1, Cytochrome P-450 CYP1B1, Cytokines/metabolism, DNA adducts, Inflammation, Inflammation Mediators/*pharmacology, metabolism, Oxidoreductases Acting on Aldehyde or Oxo Group Donors/biosynthesis/genetics, Polycyclic aromatic hydrocarbons, Pulmonary Alveoli/cytology/drug effects/*metabolism, Rats, Real-Time Polymerase Chain Reaction, RNA, Small Interfering, Subfamily B/biosynthesis/genetics, Tandem Mass Spectrometry, Transfection, Western},

pubstate = {published},

tppubtype = {article}

}

@article{knopfova_c-myb_2012,

title = {c-Myb regulates matrix metalloproteinases 1/9, and cathepsin D: implications for matrix-dependent breast cancer cell invasion and metastasis.},

author = {Lucia Knopfová and Petr Beneš and Lucie Pekarčíková and Markéta Hermanová and Michal Masařík and Zuzana Pernicová and Karel Souček and Jan Smarda},

doi = {10.1186/1476-4598-11-15},

issn = {1476-4598},

year  = {2012},

date = {2012-03-01},

journal = {Molecular cancer},

volume = {11},

pages = {15},

abstract = {BACKGROUND: The c-Myb transcription factor is essential for the maintenance of stem-progenitor cells in bone marrow, colon epithelia, and neurogenic niches. c-Myb malfunction contributes to several types of malignancies including breast cancer. However, the function of c-Myb in the metastatic spread of breast tumors remains unexplored. In this study, we report a novel role of c-Myb in the control of specific proteases that regulate the matrix-dependent invasion of breast cancer cells. RESULTS: Ectopically expressed c-Myb enhanced migration and ability of human MDA-MB-231 and mouse 4T1 mammary cancer cells to invade Matrigel but not the collagen I matrix in vitro. c-Myb strongly increased the expression/activity of cathepsin D and matrix metalloproteinase (MMP) 9 and significantly downregulated MMP1. The gene coding for cathepsin D was suggested as the c-Myb-responsive gene and downstream effector of the migration-promoting function of c-Myb. Finally, we demonstrated that c-Myb delayed the growth of mammary tumors in BALB/c mice and affected the metastatic potential of breast cancer cells in an organ-specific manner. CONCLUSIONS: This study identified c-Myb as a matrix-dependent regulator of invasive behavior of breast cancer cells.},

note = {Place: England},

keywords = {Animals, Breast Neoplasms/genetics/*metabolism, Cathepsin D/genetics/*metabolism, Cell Line, Cell Movement/genetics/physiology, Electrophoresis, Female, Humans, Immunoblotting, Inbred BALB C, Matrix Metalloproteinase 1/genetics/*metabolism, Matrix Metalloproteinase 9/genetics/*metabolism, Mice, Neoplasm Metastasis/genetics/physiopathology, Polyacrylamide Gel, Proto-Oncogene Proteins c-myb/genetics/*metabolism, Real-Time Polymerase Chain Reaction, RNA, Small Interfering, Tumor},

pubstate = {published},

tppubtype = {article}

}

@article{umannova_benzopyrene_2011,

title = {Benzo[a]pyrene and tumor necrosis factor-α coordinately increase genotoxic damage and the production of proinflammatory mediators in alveolar epithelial type II cells.},

author = {Lenka Umannová and Miroslav Machala and Jan Topinka and Jana Schmuczerová and Pavel Krčmář and Jiří Neča and Klára Šujanová and Alois Kozubík and Jan Vondráček},

doi = {10.1016/j.toxlet.2011.06.029},

issn = {1879-3169 0378-4274},

year  = {2011},

date = {2011-10-01},

journal = {Toxicology letters},

volume = {206},

number = {2},

pages = {121–129},

abstract = {Alveolar type II epithelial (AEII) cells regulate lung inflammatory response and, simultaneously, they are a target of environmental carcinogenic factors. We employed an in vitro model of rat AEII cells, the RLE-6TN cell line, in order to analyze the interactive effects of tumor necrosis factor-α (TNF-α), a cytokine which plays a key role in the initiation of inflammatory responses in the lung, and benzo[a]pyrene (BaP), a highly carcinogenic polycyclic aromatic hydrocarbon. TNF-α strongly augmented the formation of stable BaP diol epoxide-DNA adducts in AEII cells, which was associated with enhanced p53-Ser15 phosphorylation and decreased cell survival. The increased genotoxicity of BaP was associated with altered expression of cytochrome P450 (CYP) enzymes involved in its bioactivation, a simultaneous suppression of CYP1A1 and enhancement of CYP1B1 expression. Importantly, BaP and TNF-α acted synergistically to upregulate key inflammatory regulators in AEII cells, including the expression of inducible NO synthase and cyclooxygenase-2 (COX-2), and enhanced prostaglandin E2 production and expression of proinflammatory cytokines, such as TNF-α, interleukin-1β and interleukin-6. We observed that BaP and TNF-α together strongly activated p38 kinase, a principal regulator of inflammatory response. SB202190, a specific p38 inhibitor, prevented induction of both COX-2 and proinflammatory cytokines, thus confirming that p38 activity was crucial for the observed inflammatory reaction. Taken together, our data demonstrated, for the first time, that a proinflammatory cytokine and an environmental PAH may interact to potentiate both DNA damage and the inflammatory response in AEII cells, which may occur through coordinated upregulation of p38 activity.},

note = {Place: Netherlands},

keywords = {Alveolar Epithelial Cells/*drug effects/immunology/*metabolism, Animals, Apoptosis/drug effects, Aryl Hydrocarbon Hydroxylases/genetics/metabolism, Benzo(a)pyrene/metabolism/*toxicity, Carcinogens, Cell Line, Cell Proliferation/drug effects, Cytochrome P-450 CYP1A1/genetics/metabolism, Cytochrome P-450 CYP1B1, DNA Adducts/*metabolism, Environmental/toxicity, Enzyme Activation/drug effects, Gene Expression Regulation/drug effects, Inflammation Mediators/*metabolism, Messenger/metabolism, Mutagens/*toxicity, p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism, Phosphorylation/drug effects, Post-Translational/drug effects, Protein Kinase Inhibitors/pharmacology, Protein Processing, Rats, RNA, Tumor Necrosis Factor-alpha/*metabolism, Tumor Suppressor Protein p53/metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{slabakova_tgf-1-induced_2011,

title = {TGF-β1-induced EMT of non-transformed prostate hyperplasia cells is characterized by early induction of SNAI2/Slug.},

author = {Eva Slabáková and Zuzana Pernicová and Eva Slavíčková and Andrea Staršíchová and Alois Kozubík and Karel Souček},

doi = {10.1002/pros.21350},

issn = {1097-0045 0270-4137},

year  = {2011},

date = {2011-09-01},

journal = {The Prostate},

volume = {71},

number = {12},

pages = {1332–1343},

abstract = {BACKGROUND: Epithelial-mesenchymal transition (EMT) underlying cancer cell invasion and metastasis has been thoroughly studied in prostate cancer. Although EMT markers have been clinically observed in benign prostate hyperplasia, molecular events underlying the onset and progression of EMT in benign prostate cells have not been described. METHODS: EMT in BPH-1 cells was induced by TGF-β1 treatment and the kinetics of expression of EMT markers, regulators, and selected miRNAs was assessed by western blotting and quantitative RT-PCR. RESULTS: EMT in BPH-1 cells was accompanied by rapid up-regulation of SNAI2/Slug and ZEB1 transcription factors, while changes in expression levels of ZEB2 and miR-200 family members were observed after extended time intervals. Invasive phenotype with EMT hallmarks, characterizing tumorigenic clones derived from BPH-1 cells, was associated with increased mRNA levels of SNAI2, ZEB1, and ZEB2, but was not associated with significant changes in basal levels of miR-200 family members. RNA interference revealed that SNAI2/Slug is crucial for TGF-β1-induced vimentin up-regulation and migration of BPH-1 cells. CONCLUSIONS: This study suggests that in BPH-1 cells the transcription factor SNAI2/Slug is important for EMT initiation, while the ZEB family of transcription factors in cooperation with the miR-200 family may oppose the reversal of the EMT phenotype.},

note = {Place: United States},

keywords = {*Epithelial-Mesenchymal Transition/genetics, Biomarkers/metabolism, Cell Line, Cell Movement, Homeodomain Proteins/genetics, Humans, Kinetics, Male, Messenger/metabolism, MicroRNAs/metabolism, Neoplasm Invasiveness/genetics, Phenotype, Prostatic Hyperplasia/*physiopathology, Repressor Proteins/genetics, RNA, Snail Family Transcription Factors, Transcription Factors/*biosynthesis/genetics, Transforming Growth Factor beta1/*pharmacology, Up-Regulation/drug effects, Vimentin/metabolism, Zinc Finger E-box Binding Homeobox 2, Zinc Finger E-box-Binding Homeobox 1},

pubstate = {published},

tppubtype = {article}

}

@article{starsichova_tgf-beta1_2010,

title = {TGF-beta1 suppresses IL-6-induced STAT3 activation through regulation of Jak2 expression in prostate epithelial cells.},

author = {Andrea Starsíchová and Eva Lincová and Zuzana Pernicová and Alois Kozubík and Karel Soucek},

doi = {10.1016/j.cellsig.2010.06.014},

issn = {1873-3913 0898-6568},

year  = {2010},

date = {2010-11-01},

journal = {Cellular signalling},

volume = {22},

number = {11},

pages = {1734–1744},

abstract = {Chronic inflammation plays an important role in the initiation and progression of various human diseases including benign prostatic hyperplasia or prostate cancer. Here we show that the proinflammatory cytokine interleukin-6 (IL-6) has prosurvival effects and chronically activates the Jak2/STAT3 signalling pathway in a model of benign prostatic hyperplasia (BPH-1). We demonstrate that the antiinflammatory cytokine transforming growth factor-beta1 (TGF-beta1), which also permanently activates its canonical signalling pathway through SMAD proteins in BPH-1 cells, modifies the effects of IL-6 on cell proliferation. Importantly, TGF-beta1 inhibits IL-6 signal transduction by decreasing the phosphorylation levels of STAT3. This effect is associated with decreased expression of Jak2 at both mRNA and protein levels. Moreover, we showed that TGF-beta1 inhibits IL-6-induced expression of the cancer-associated gene MUC1. These observations demonstrated a novel interaction between TGF-beta1 and IL-6 signalling and suggested another mechanism of how defects in TGF-beta signalling, frequently associated with prostate pathologies, can contribute to the disruption of tissue homeostasis.},

note = {Place: England},

keywords = {Cell Line, Cell Proliferation, Epithelial Cells/*metabolism, Humans, Interleukin-6/*antagonists & inhibitors/pharmacology, Janus Kinase 2/genetics/*metabolism, Male, Mucin-1/metabolism, Phosphorylation, Prostate/cytology/enzymology/*metabolism, Prostatic Hyperplasia/enzymology/*metabolism, RNA, RNA Interference, Signal Transduction, Smad Proteins/metabolism, Small Interfering/metabolism, STAT3 Transcription Factor/*metabolism, Transforming Growth Factor beta1/*pharmacology},

pubstate = {published},

tppubtype = {article}

}

@article{gavelova_reduction_2008,

title = {Reduction of doxorubicin and oracin and induction of carbonyl reductase in human breast carcinoma MCF-7 cells.},

author = {Martina Gavelová and Jana Hladíková and Lenka Vildová and Romana Novotná and Jan Vondrácek and Pavel Krcmár and Miroslav Machala and Lenka Skálová},

doi = {10.1016/j.cbi.2008.07.011},

issn = {0009-2797},

year  = {2008},

date = {2008-10-01},

journal = {Chemico-biological interactions},

volume = {176},

number = {1},

pages = {9–18},

abstract = {In cancer cells, the drug-metabolizing enzymes may deactivate cytostatics, thus contributing to their survival. Moreover, the induction of these enzymes may also contribute to development of drug-resistance through acceleration of cytostatics deactivation. However, the principal metabolic pathways contributing to deactivation of many cytostatics still remain poorly defined. The main aims of the present study were: (i) to compare the reductive deactivation of cytostatic drugs doxorubicin (DOX) and oracin (ORC) in human breast cancer MCF-7 cells; (ii) to identify major enzyme(s) involved in the carbonyl reduction; and iii) to evaluate the activities and expression of selected carbonyl reducing enzymes in MCF-7 cells upon a short-term (48 h) exposure to either DOX or ORC. We found that MCF-7 cells were able to effectively metabolize both DOX and ORC through reduction of their carbonyl groups. The reduction of ORC was stereospecific, with a preferential formation of + enantiomer of dihydrooracin (DHO). The cytosolic carbonyl reductase CBR1 seemed to be a principal enzyme reducing both drugs, while cytosolic aldo-keto reductase AKR1C3 or microsomal reductases probably did not play important role in metabolism of either DOX or ORC. The exposure of MCF-7 cells to low (nanomolar) concentrations of DOX or ORC caused a significant elevation of reduction rates of both cytostatics, accompanied with an increase of CBR1 protein levels. Taken together, the present results seem to suggest that the accelerated metabolic deactivation of ORC or DOX might contribute to the survival of breast cancer cells during exposure to these cytostatics.},

note = {Place: Ireland},

keywords = {3-Hydroxysteroid Dehydrogenases/antagonists & inhibitors/genetics/metabolism, Alcohol Oxidoreductases/antagonists & inhibitors/*biosynthesis/genetics/metabolism, Aldehyde Reductase, Aldo-Keto Reductase Family 1 Member C3, Aldo-Keto Reductases, Biotransformation/drug effects, Blotting, Breast Neoplasms/*enzymology/genetics, Cell Line, Dose-Response Relationship, Doxorubicin/analogs & derivatives/chemistry/*metabolism/pharmacology, Drug, Enzyme Induction/drug effects, Enzyme Inhibitors/pharmacology, Ethanolamines/chemistry/*metabolism/pharmacology, Gene Expression Regulation, Humans, Hydroxyprostaglandin Dehydrogenases/antagonists & inhibitors/genetics/metabolism, Isoquinolines/chemistry/*metabolism/pharmacology, Kinetics, Messenger/genetics/metabolism, Methacrylates/pharmacology, Neoplastic/drug effects, Oxidation-Reduction/drug effects, Phenylpropionates/pharmacology, Quercetin/analogs & derivatives/pharmacology, RNA, Subcellular Fractions/drug effects/metabolism, Tumor, Western},

pubstate = {published},

tppubtype = {article}

}

@article{marvanova_toxic_2008,

title = {Toxic effects of methylated benz[a]anthracenes in liver cells.},

author = {Sona Marvanová and Jan Vondrácek and Katerrina Penccíková and Lenka Trilecová and Pavel Krcmárr and Jan Topinka and Zuzana Nováková and Alena Milcová and Miroslav Machala},

doi = {10.1021/tx700305x},

issn = {0893-228X},

year  = {2008},

date = {2008-02-01},

journal = {Chemical research in toxicology},

volume = {21},

number = {2},

pages = {503–512},

abstract = {Monomethylated benz[ a]anthracenes (MeBaAs) are an important group of methylated derivatives of polycyclic aromatic hydrocarbons (PAHs). Although the methyl substitution reportedly affects their mutagenicity and tumor-initiating activity, little is known about the impact of methylation on the effects associated with activation of the aryl hydrocarbon receptor (AhR)-dependent gene expression and/or toxic events associated with tumor promotion. In the present study, we studied the effects of a series of MeBaAs on the above-mentioned end points in rat liver cell lines and compared them with the effects of benz[ a]anthracene (BaA) and the potent carcinogen 7,12-dimethylbenz[ a]anthracene (DMBA). Methyl substitution enhanced the AhR-mediated activity of BaA derivatives determined in a reporter gene assay, as the induction equivalency factors (IEFs) of all MeBaAs were higher than that of BaA. IEFs of 6-MeBaA and 9-MeBaA, two of the most potent MeBaAs, were more than two orders of magnitude higher than the IEF of BaA. Correspondingly, all MeBaAs induced higher levels of cytochrome P450 1A1 mRNA. Both BaA and MeBaAs had similar effects on the expression of cytochrome P450 1B1 or aldo-keto reductase 1C9 in rat liver epithelial WB-F344 cells. In contrast to genotoxic DMBA, MeBaAs induced low DNA adduct formation. Only 10-MeBaA induced apoptosis and accumulation of phosphorylated p53, which could be associated with the induction of oxidative stress, similar to DMBA. With the exception of 10-MeBaA, all MeBaAs induced cell proliferation in contact-inhibited WB-F344 cells, which corresponded with their ability to activate AhR. 1-, 2-, 8-, 10-, 11-, and 12-MeBaA inhibited gap junctional intercellular communication (GJIC) in WB-F344 cells. This mode of action, like disruption of cell proliferation control, might contribute to tumor promotion. Taken together, these data showed that the methyl substitution significantly influences those effects of MeBaAs associated with AhR activation or GJIC inhibition.},

note = {Place: United States},

keywords = {10-Dimethyl-1, 2-benzanthracene/chemistry/metabolism/toxicity, 9, Animals, Apoptosis/drug effects, Benz(a)Anthracenes/chemistry/metabolism/*toxicity, Carcinoma, Cell Line, Cell Proliferation/drug effects, Cytochrome P-450 Enzyme System/genetics/metabolism, DNA Adducts/analysis/metabolism, DNA/drug effects/metabolism, Dose-Response Relationship, Drug, Enzyme Induction, Enzymologic/drug effects, Gap Junctions/drug effects, Gene Expression Regulation, Genes, Hepatocellular, Hepatocytes/*drug effects/metabolism/pathology, Inbred F344, Liver Neoplasms, Messenger/metabolism, Methylation, Rats, Reporter/drug effects, RNA, Stem Cells/*drug effects/metabolism/pathology, Tumor},

pubstate = {published},

tppubtype = {article}

}

@article{topinka_dna_2008,

title = {DNA adducts formation and induction of apoptosis in rat liver epithelial 'stem-like' cells exposed to carcinogenic polycyclic aromatic hydrocarbons.},

author = {Jan Topinka and Sona Marvanová and Jan Vondrácek and Oksana Sevastyanova and Zuzana Nováková and Pavel Krcmár and Katerina Pencíková and Miroslav Machala},

doi = {10.1016/j.mrfmmm.2007.09.004},

issn = {0027-5107},

year  = {2008},

date = {2008-02-01},

journal = {Mutation research},

volume = {638},

number = {1-2},

pages = {122–132},

abstract = {The bipotent liver progenitor cells, so called oval cells, may participate at the early stages of hepatocarcinogenesis induced by chemical carcinogens. Unlike in mature parenchymal cells, little is known about formation of DNA adducts and other genotoxic events in oval cells. In the present study, we employed spontaneously immortalized rat liver WB-F344 cell line, which is an established in vitro model of oval cells, in order to study genotoxic effects of selected carcinogenic polycyclic aromatic hydrocarbons (PAHs). With exception of dibenzo[a,l]pyrene, and partly also benzo[g]chrysene and benz[a]anthracene, all other PAHs under the study induced high levels of CYP1A1 and CYP1B1 mRNA. In contrast, we observed distinct genotoxic and cytotoxic potencies of PAHs. Dibenzo[a,l]pyrene, and to a lesser extent also benzo[a]pyrene, benzo[g]chrysene and dibenzo[a,e]pyrene, formed high levels of DNA adducts. This was accompanied with accumulation of Ser-15 phosphorylated form of p53 protein and induction of apoptosis. Contrary to that, benz[a]anthracene, chrysene, benzo[b]fluoranthene and dibenzo[a,h]anthracene induced only low amounts of DNA adducts formation and minimal apoptosis, without exerting significant effects on p53 phosphorylation. Finally, we studied effects of 2,4,3',5'-tetramethoxystilbene and fluoranthene, inhibitors of CYP1B1 activity, which plays a central role in metabolic activation of dibenzo[a,l]pyrene. In a dose-dependent manner, both compounds inhibited apoptosis induced by dibenzo[a,l]pyrene, suggesting that it interferes with the metabolic activation of the latter one. The present data show that in model cell line sharing phenotypic properties with oval cells, PAHs can be efficiently metabolized to form ultimate genotoxic metabolites. Liver progenitor cells could be thus susceptible to this type of genotoxic insult, which makes WB-F344 cell line a useful tool for studies of genotoxic effects of organic contaminants in liver cells. Our results also suggest that, unlike in mature hepatocytes, CYP1B1 might be a primary enzyme responsible for formation of DNA adducts in liver progenitor cells.},

note = {Place: Netherlands},

keywords = {*Apoptosis, Animals, Aryl Hydrocarbon Hydroxylases/genetics, Cells, Cultured, Cytochrome P-450 CYP1A1/genetics, Cytochrome P-450 CYP1B1, DNA Adducts/*metabolism, Inbred F344, Liver/*cytology, Messenger/analysis, Polycyclic Aromatic Hydrocarbons/*pharmacology, Rats, RNA, Stem Cells/*metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{andrysik_aryl_2007,

title = {The aryl hydrocarbon receptor-dependent deregulation of cell cycle control induced by polycyclic aromatic hydrocarbons in rat liver epithelial cells.},

author = {Zdenek Andrysík and Jan Vondrácek and Miroslav Machala and Pavel Krcmár and Lenka Svihálková-Sindlerová and Anne Kranz and Carsten Weiss and Dagmar Faust and Alois Kozubík and Cornelia Dietrich},

doi = {10.1016/j.mrfmmm.2006.10.004},

issn = {0027-5107},

year  = {2007},

date = {2007-02-01},

journal = {Mutation research},

volume = {615},

number = {1-2},

pages = {87–97},

abstract = {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.},

note = {Place: Netherlands},

keywords = {Animals, Apoptosis/drug effects, Aryl Hydrocarbon/antagonists & inhibitors/genetics/*metabolism, Base Sequence, Benz(a)Anthracenes/toxicity, Benzo(a)pyrene/toxicity, Cell Cycle Proteins/metabolism, Cell Cycle/*drug effects/*physiology, Cell Line, Cell Proliferation/drug effects, Cyclin A/metabolism, Cyclin-Dependent Kinase 2/metabolism, Cytochrome P-450 CYP1A1/genetics, Epithelial Cells/cytology/drug effects/metabolism, Fluorenes/toxicity, Gene Expression/drug effects, Hepatocytes/cytology/*drug effects/*metabolism, Messenger/genetics/metabolism, Multiprotein Complexes, Mutagens/toxicity, Mutation, Polycyclic Aromatic Hydrocarbons/*toxicity, Rats, Receptors, RNA, Small Interfering/genetics},

pubstate = {published},

tppubtype = {article}

}