Latest Publications

@article{besse_hiv-protease_2024,

title = {HIV-protease inhibitors potentiate the activity of carfilzomib in triple-negative breast cancer.},

author = {Andrej Besse and Lenka Sedlarikova and Lorina Buechler and Marianne Kraus and Chieh-Hsiang Yang and Nicol Strakova and Karel Soucek and Jiri Navratil and Marek Svoboda and Alana L. Welm and Markus Joerger and Christoph Driessen and Lenka Besse},

doi = {10.1038/s41416-024-02774-9},

issn = {1532-1827 0007-0920},

year  = {2024},

date = {2024-09-01},

journal = {British journal of cancer},

volume = {131},

number = {5},

pages = {918–930},

abstract = {BACKGROUND: Resistance to chemotherapy is a major problem in the treatment of patients with triple-negative breast cancer (TNBC). Preclinical data suggest that TNBC is dependent on proteasomes; however, clinical observations indicate that the efficacy of proteasome inhibitors in TNBC may be limited, suggesting the need for combination therapies. METHODS: We compared bortezomib and carfilzomib and their combinations with nelfinavir and lopinavir in TNBC cell lines and primary cells with regard to their cytotoxic activity, functional proteasome inhibition, and induction of the unfolded protein response (UPR). Furthermore, we evaluated the involvement of sXBP1, ABCB1, and ABCG2 in the cytotoxic activity of drug combinations. RESULTS: Carfilzomib, via proteasome β5 + β2 inhibition, is more cytotoxic in TNBC than bortezomib, which inhibits β5 + β1 proteasome subunits. The cytotoxicity of carfilzomib was significantly potentiated by nelfinavir or lopinavir. Carfilzomib with lopinavir induced endoplasmic reticulum stress and pro-apoptotic UPR through the accumulation of excess proteasomal substrate protein in TNBC in vitro. Moreover, lopinavir increased the intracellular availability of carfilzomib by inhibiting carfilzomib export from cells that express high levels and activity of ABCB1, but not ABCG2. CONCLUSION: Proteasome inhibition by carfilzomib combined with nelfinavir/lopinavir represents a potential treatment option for TNBC, warranting further investigation.},

note = {Place: England},

keywords = {*ATP Binding Cassette Transporter, *Bortezomib/pharmacology, *Drug Synergism, *HIV Protease Inhibitors/pharmacology, *Lopinavir/pharmacology, *Nelfinavir/pharmacology, *Oligopeptides/pharmacology, *Triple Negative Breast Neoplasms/drug therapy/pathology, *Unfolded Protein Response/drug effects, Antineoplastic Combined Chemotherapy Protocols/pharmacology, Apoptosis/drug effects, ATP Binding Cassette Transporter, Cell Line, Endoplasmic Reticulum Stress/drug effects, Female, Humans, Member 2/metabolism/antagonists & inhibitors, Neoplasm Proteins/antagonists & inhibitors/metabolism, Proteasome Inhibitors/pharmacology, Subfamily B/metabolism, Subfamily G, Tumor, X-Box Binding Protein 1/metabolism/genetics},

pubstate = {published},

tppubtype = {article}

}

@article{herudkova_chk1_2017,

title = {Chk1 Inhibitor SCH900776 Effectively Potentiates the Cytotoxic Effects of Platinum-Based Chemotherapeutic Drugs in Human Colon Cancer Cells.},

author = {Jarmila Herůdková and Kamil Paruch and Prashant Khirsariya and Karel Souček and Martin Krkoška and Olga Vondálová Blanářová and Petr Sova and Alois Kozubík and Alena Hyršlová Vaculová},

doi = {10.1016/j.neo.2017.08.002},

issn = {1476-5586 1522-8002},

year  = {2017},

date = {2017-10-01},

journal = {Neoplasia (New York, N.Y.)},

volume = {19},

number = {10},

pages = {830–841},

abstract = {Although Chk1 kinase inhibitors are currently under clinical investigation as effective cancer cell sensitizers to the cytotoxic effects of numerous chemotherapeutics, there is still a considerable uncertainty regarding their role in modulation of anticancer potential of platinum-based drugs. Here we newly demonstrate the ability of one of the most specific Chk1 inhibitors, SCH900776 (MK-8776), to enhance human colon cancer cell sensitivity to the cytotoxic effects of platinum(II) cisplatin and platinum(IV)- LA-12 complexes. The combined treatment with SCH900776 and cisplatin or LA-12 results in apparent increase in G1/S phase-related apoptosis, stimulation of mitotic slippage, and senescence of HCT116 cells. We further show that the cancer cell response to the drug combinations is significantly affected by the p21, p53, and PTEN status. In contrast to their wt counterparts, the p53- or p21-deficient cells treated with SCH900776 and cisplatin or LA-12 enter mitosis and become polyploid, and the senescence phenotype is strongly suppressed. While the cell death induced by SCH900776 and cisplatin or LA-12 is significantly delayed in the absence of p53, the anticancer action of the drug combinations is significantly accelerated in p21-deficient cells, which is associated with stimulation of apoptosis beyond G2/M cell cycle phase. We also show that cooperative killing action of the drug combinations in HCT116 cells is facilitated in the absence of PTEN. Our results indicate that SCH900776 may act as an important modulator of cytotoxic response triggered by platinum-based drugs in colon cancer cells.},

note = {Place: United States},

keywords = {Antineoplastic Agents/*pharmacology, Apoptosis/drug effects, Cell Cycle/drug effects/genetics, Cell Line, Cell Survival/drug effects, Cellular Senescence/drug effects, Checkpoint Kinase 1/*antagonists & inhibitors/genetics/*metabolism, Cisplatin/pharmacology, Colonic Neoplasms/drug therapy/genetics/*metabolism/pathology, Cyclin-Dependent Kinase Inhibitor p21/genetics/metabolism, DNA Damage/drug effects, Gene Knockout Techniques, Humans, Platinum Compounds/*pharmacology, Pyrazoles/*pharmacology, Pyrimidines/*pharmacology, Tumor, Tumor Suppressor Protein p53/genetics/metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{samadder_synthesis_2017,

title = {Synthesis and Profiling of a Novel Potent Selective Inhibitor of CHK1 Kinase Possessing Unusual N-trifluoromethylpyrazole Pharmacophore Resistant to Metabolic N-dealkylation.},

author = {Pounami Samadder and Tereza Suchánková and Ondřej Hylse and Prashant Khirsariya and Fedor Nikulenkov and Stanislav Drápela and Nicol Straková and Petr Vaňhara and Kateřina Vašíčková and Hana Kolářová and Lucia Binó and Miroslava Bittová and Petra Ovesná and Peter Kollár and Radek Fedr and Milan Ešner and Josef Jaroš and Aleš Hampl and Lumír Krejčí and Kamil Paruch and Karel Souček},

doi = {10.1158/1535-7163.MCT-17-0018},

issn = {1538-8514 1535-7163},

year  = {2017},

date = {2017-09-01},

journal = {Molecular cancer therapeutics},

volume = {16},

number = {9},

pages = {1831–1842},

abstract = {Checkpoint-mediated dependency of tumor cells can be deployed to selectively kill them without substantial toxicity to normal cells. Specifically, loss of CHK1, a serine threonine kinase involved in the surveillance of the G(2)-M checkpoint in the presence of replication stress inflicted by DNA-damaging drugs, has been reported to dramatically influence the viability of tumor cells. CHK1's pivotal role in maintaining genomic stability offers attractive opportunity for increasing the selectivity, effectivity, and reduced toxicity of chemotherapy. Some recently identified CHK1 inhibitors entered clinical trials in combination with DNA antimetabolites. Herein, we report synthesis and profiling of MU380, a nontrivial analogue of clinically profiled compound SCH900776 possessing the highly unusual N-trifluoromethylpyrazole motif, which was envisioned not to undergo metabolic oxidative dealkylation and thereby provide greater robustness to the compound. MU380 is a selective and potent inhibitor of CHK1 which sensitizes a variety of tumor cell lines to hydroxyurea or gemcitabine up to 10 times. MU380 shows extended inhibitory effects in cells, and unlike SCH900776, does not undergo in vivo N-dealkylation to the significantly less selective metabolite. Compared with SCH900776, MU380 in combination with GEM causes higher accumulation of DNA damage in tumor cells and subsequent enhanced cell death, and is more efficacious in the A2780 xenograft mouse model. Overall, MU380 represents a novel state-of-the-art CHK1 inhibitor with high potency, selectivity, and improved metabolic robustness to oxidative N-dealkylation. Mol Cancer Ther; 16(9); 1831-42. ©2017 AACR.},

note = {Place: United States},

keywords = {Animal, Animals, Antineoplastic Agents/*chemical synthesis/*pharmacology, Apoptosis/drug effects, Biomarkers, Cell Cycle Checkpoints/drug effects, Cell Cycle/drug effects, Cell Line, Checkpoint Kinase 1/*antagonists & inhibitors, Dealkylation/drug effects, Disease Models, Dose-Response Relationship, Drug, Drug resistance, Humans, Methylation, Mice, Molecular Structure, Neoplasm/*drug effects, Protein Kinase Inhibitors/*chemical synthesis/*pharmacology, Pyrazoles/pharmacology, Pyrimidines/pharmacology, Tumor, Xenograft Model Antitumor Assays},

pubstate = {published},

tppubtype = {article}

}

@article{hofmanova_dietary_2017,

title = {Dietary fatty acids specifically modulate phospholipid pattern in colon cells with distinct differentiation capacities.},

author = {Jiřina Hofmanová and Josef Slavík and Petra Ovesná and Zuzana Tylichová and Jan Vondráček and Nicol Straková and Alena Hyršlová Vaculová and Miroslav Ciganek and Alois Kozubík and Lucie Knopfová and Jan Šmarda and Miroslav Machala},

doi = {10.1007/s00394-016-1196-y},

issn = {1436-6215 1436-6207},

year  = {2017},

date = {2017-06-01},

journal = {European journal of nutrition},

volume = {56},

number = {4},

pages = {1493–1508},

abstract = {PURPOSE: Although beneficial effects of the dietary n-3 docosahexaenoic acid (DHA) or butyrate in colon carcinogenesis have been implicated, the mechanisms of their action are not fully clear. Here, we investigated modulations of composition of individual phospholipid (PL) classes, with a particular emphasis on cardiolipins (CLs), in colon cells treated with DHA, sodium butyrate (NaBt), or their combination (DHA/NaBt), and we evaluated possible associations between lipid changes and cell fate after fatty acid treatment. METHODS: In two distinct human colon cell models, foetal colon (FHC) and adenocarcinoma (HCT-116) cells, we compared patterns and composition of individual PL classes following the fatty acid treatment by HPLC-MS/MS. In parallel, we measured the parameters reflecting cell proliferation, differentiation and death. RESULTS: In FHC cells, NaBt induced primarily differentiation, while co-treatment with DHA shifted their response towards cell death. In contrast, NaBt induced apoptosis in HCT-116 cells, which was not further affected by DHA. DHA was incorporated in all main PL types, increasing their unsaturation, while NaBt did not additionally modulate these effects in either cell model. Nevertheless, we identified an unusually wide range of CL species to be highly increased by NaBt and particularly by DHA/NaBt, and these effects were more pronounced in HCT-116 cells. DHA and DHA/NaBt enhanced levels of high molecular weight and more unsaturated CL species, containing DHA, which was specific for either differentiation or apoptotic responses. CONCLUSIONS: We identified a wide range of CL species in the colon cells which composition was significantly modified after DHA and NaBt treatment. These specific CL modulations might contribute to distinct cellular differentiation or apoptotic responses.},

note = {Place: Germany},

keywords = {Apoptosis, Apoptosis/drug effects, Butyrate, Butyric Acid/pharmacology, Cardiolipins, Caspase 3/genetics/metabolism, Cell Differentiation/*drug effects, Cell Line, Cell Proliferation/drug effects, Colon cancer, Colon/cytology/*drug effects, Docosahexaenoic acid, Docosahexaenoic Acids/*pharmacology, HCT116 Cells, Humans, Phospholipids, Phospholipids/*chemistry, Tandem Mass Spectrometry, Tumor},

pubstate = {published},

tppubtype = {article}

}

@article{palkova_aryl_2015,

title = {The aryl hydrocarbon receptor-mediated and genotoxic effects of fractionated extract of standard reference diesel exhaust particle material in pulmonary, liver and prostate cells.},

author = {Lenka Pálková and Jan Vondráček and Lenka Trilecová and Miroslav Ciganek and Kateřina Pěnčíková and Jiří Neča and Alena Milcová and Jan Topinka and Miroslav Machala},

doi = {10.1016/j.tiv.2014.12.002},

issn = {1879-3177 0887-2333},

year  = {2015},

date = {2015-04-01},

journal = {Toxicology in vitro : an international journal published in association with BIBRA},

volume = {29},

number = {3},

pages = {438–448},

abstract = {Diesel exhaust particles (DEP) and the associated complex mixtures of organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), or their derivatives, have been suggested to exert deleterious effects on human health. We used a set of defined cellular models representing liver, lung and prostate tissues, in order to compare non-genotoxic and genotoxic effects of crude and fractionated extract of a standard reference DEP material - SRM 1650b. We focused on the aryl hydrocarbon receptor (AhR)-mediated activity, modulation of cell proliferation, formation of DNA adducts, oxidative DNA damage, and induction of DNA damage responses, including evaluation of apoptosis, and phosphorylation of p53 tumor suppressor and checkpoint kinases (Chk). Both PAHs and the polar aromatic compounds contributed to the AhR-mediated activity of DEP-associated organic pollutants. The principal identified AhR agonists included benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene, chrysene and several non-priority PAHs, including benzochrysenes and methylated PAHs. In contrast to PAHs, polar compounds contributed more significantly to overall formation of DNA adducts associated with phosphorylation of p53, Chk1 or Chk2, and partly with apoptosis. Therefore, more attention should be paid to identification of DEP-associated polar organic compounds, contributing to the AhR activation and cytotoxic/genotoxic effects of complex airborne mixtures of organic contaminants produced by diesel engines.},

note = {Place: England},

keywords = {Air Pollutants/*toxicity, Air pollution, Animals, Apoptosis, Apoptosis/drug effects, Aryl Hydrocarbon/*drug effects, Cell Cycle/drug effects, Cell Death/drug effects, Cell Proliferation, DNA adducts, DNA Damage, DNA damage response, Liver/*pathology, Lung/*pathology, Male, Mutagens/*toxicity, PAHs, Particulate Matter/*toxicity, Prostate/*pathology, Rats, Receptors, SRM 1650b, Vehicle Emissions/*toxicity},

pubstate = {published},

tppubtype = {article}

}

@article{steinmetz_oncogene_2014,

title = {The oncogene EVI1 enhances transcriptional and biological responses of human myeloid cells to all-trans retinoic acid.},

author = {Birgit Steinmetz and Hubert Hackl and Eva Slabáková and Ilse Schwarzinger and Monika Smějová and Andreas Spittler and Itziar Arbesu and Medhat Shehata and Karel Souček and Rotraud Wieser},

doi = {10.4161/15384101.2014.946869},

issn = {1551-4005 1538-4101},

year  = {2014},

date = {2014-01-01},

journal = {Cell cycle (Georgetown, Tex.)},

volume = {13},

number = {18},

pages = {2931–2943},

abstract = {The product of the ecotropic virus integration site 1 (EVI1) gene, whose overexpression is associated with a poor prognosis in myeloid leukemias and some epithelial tumors, regulates gene transcription both through direct DNA binding and through modulation of the activity of other sequence specific transcription factors. Previous results from our laboratory have shown that EVI1 influenced transcription regulation in response to the myeloid differentiation inducing agent, all-trans retinoic acid (ATRA), in a dual manner: it enhanced ATRA induced transcription of the RARβ gene, but repressed the ATRA induction of the EVI1 gene itself. In the present study, we asked whether EVI1 would modulate the ATRA regulation of a larger number of genes, as well as biological responses to this agent, in human myeloid cells. U937 and HL-60 cells ectopically expressing EVI1 through retroviral transduction were subjected to microarray based gene expression analysis, and to assays measuring cellular proliferation, differentiation, and apoptosis. These experiments showed that EVI1 modulated the ATRA response of several dozens of genes, and in fact reinforced it in the vast majority of cases. A particularly strong synergy between EVI1 and ATRA was observed for GDF15, which codes for a member of the TGF-β superfamily of cytokines. In line with the gene expression results, EVI1 enhanced cell cycle arrest, differentiation, and apoptosis in response to ATRA, and knockdown of GDF15 counteracted some of these effects. The potential clinical implications of these findings are discussed.},

note = {Place: United States},

keywords = {*Oncogenes, acute myeloid leukemia, acute promyelocytic leukemia, all-trans retinoic acid, AML, APL, Apoptosis, Apoptosis/drug effects, Ar, ATRA, ATRA regulation, Cell Cycle, Cell Cycle Checkpoints/drug effects, Cell Differentiation/drug effects, dimethyl sulfoxide, DMSO, DNA-Binding Proteins/genetics/*metabolism, Down-Regulation/drug effects, Em, Epithelial Cells/drug effects/metabolism, Er, EVI1, EVI1 modulation, EVI1 regulation, false discovery rate, FBS, FC, FDR, fetal bovine serum, fold change, GDF15, Gene Expression Profiling, Gene Knockdown Techniques, Genetic/*drug effects, GFP, green fluorescent protein, Growth Differentiation Factor 15/genetics/metabolism, HL-60 Cells, Humans, mcoEvi1, MDS, MDS1 and EVI1 Complex Locus Protein, murine codon optimized Evi1, myelodysplastic syndrome, Myeloid Cells/drug effects/*metabolism, myeloid differentiation, penicillin streptomycin glutamine, Proto-Oncogenes/genetics, PSG, RAR, RARE, Real-Time Polymerase Chain Reaction, Reproducibility of Results, retinoic acid receptor, retinoic acid response element, SE, standard error, Transcription, Transcription Factors/genetics/*metabolism, Tretinoin/*pharmacology},

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{andrysik_activation_2011,

title = {Activation of the aryl hydrocarbon receptor is the major toxic mode of action of an organic extract of a reference urban dust particulate matter mixture: the role of polycyclic aromatic hydrocarbons.},

author = {Zdeněk Andrysík and Jan Vondráček and Soňa Marvanová and Miroslav Ciganek and Jiří Neča and Kateřina Pěnčíková and Brinda Mahadevan and Jan Topinka and William M. Baird and Alois Kozubík and Miroslav Machala},

doi = {10.1016/j.mrfmmm.2011.06.011},

issn = {0027-5107},

year  = {2011},

date = {2011-09-01},

journal = {Mutation research},

volume = {714},

number = {1-2},

pages = {53–62},

abstract = {Many of the toxic and carcinogenic effects of urban air pollution have been linked to polycyclic aromatic hydrocarbons (PAHs) adsorbed to airborne particulate matter (PM). The carcinogenic properties of PAHs in complex organic mixtures derived from PM have been chiefly attributed to their mutagenicity. Nevertheless, PAHs are also potent activators of the aryl hydrocarbon receptor (AhR), which may contribute to their nongenotoxic effects, including tumor promotion. As the genotoxicity of carcinogenic PAHs in complex mixtures derived from urban PM is often inhibited by other mixture constituents, the AhR-mediated activity of urban PM extracts might significantly contribute to the carcinogenic activity of such mixtures. In the present study, we used an organic extract of the urban dust standard reference material, SRM1649a, as a model mixture to study a range of toxic effects related to DNA damage and AhR activation. Both the organic extract and its neutral aromatic fraction formed a low number of DNA adducts per nucleotide in the liver epithelial WB-F344 cells model, without inducing DNA damage response, such as tumor suppressor p53 activation and apoptosis. In contrast, we found that this extract, as well as its neutral and polar fractions, were potent inducers of a range of AhR-mediated responses, including induction of the AhR-mediated transcription, such as cytochrome P450 1A1/1B1 expression, and the AhR-dependent cell proliferation. Importantly, these toxic events occurred at doses one order of magnitude lower than DNA damage. The AhR-mediated activity of the neutral fraction was linked to PAHs and their derivatives, as polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls were only minor contributors to the overall AhR-mediated activity. Taken together, our data suggest that more attention should be paid to the AhR-dependent nongenotoxic events elicited by urban PM constituents, especially PAHs and their derivatives.},

note = {Place: Netherlands},

keywords = {Animals, Apoptosis/drug effects, Aryl Hydrocarbon/*metabolism, Cell Line, Cell Proliferation/drug effects, Cytochrome P-450 CYP1A1/metabolism, DNA Adducts/drug effects, DNA Damage/*drug effects, Dose-Response Relationship, Drug, Genes, Liver/drug effects, Mutagens/*toxicity, Organic Chemicals/*toxicity, p53/drug effects, Particulate Matter/*toxicity, Polycyclic Aromatic Hydrocarbons/*toxicity, Rats, Receptors},

pubstate = {published},

tppubtype = {article}

}

@article{trilecova_toxic_2011,

title = {Toxic effects of methylated benzo[a]pyrenes in rat liver stem-like cells.},

author = {Lenka Trilecová and Simona Krčková and Soňa Marvanová and Kateřina Pĕnčíková and Pavel Krčmář and Jiří Neča and Petra Hulinková and Lenka Pálková and Miroslav Ciganek and Alena Milcová and Jan Topinka and Jan Vondráček and Miroslav Machala},

doi = {10.1021/tx200049x},

issn = {1520-5010 0893-228X},

year  = {2011},

date = {2011-06-01},

journal = {Chemical research in toxicology},

volume = {24},

number = {6},

pages = {866–876},

abstract = {The methylated benzo[a]pyrenes (MeBaPs) are present at significant levels in the environment, especially in the sediments contaminated by petrogenic PAHs. However, the existing data on their toxic effects in vitro and/or in vivo are still largely incomplete. Transcription factor AhR plays a key role in the metabolic activation of PAHs to genotoxic metabolites, but the AhR activation may also contribute to the tumor promoting effects of PAHs. In this study, the AhR-mediated activity of five selected MeBaP isomers was estimated in the DR-CALUX reporter gene assay performed in rat hepatoma cells. Detection of other effects, including induction of CYP1A1, CYP1B1, and AKR1C9 mRNAs, DNA adduct formation, production of reactive oxygen species, oxidation of deoxyguanosine, and cell cycle modulation and apoptosis, was performed in the rat liver epithelial WB-F344 cell line, a model of liver progenitor cells. We identified 1-MeBaP as the most potent inducer of AhR activation, stable DNA adduct formation, checkpoint kinase 1 and p53 phosphorylation, and apoptosis. These effects suggest that 1-MeBaP is a potent genotoxin eliciting a typical sequence of events ascribed to carcinogenic PAHs: induction of CYP1 enzymes, formation of high levels of DNA adducts, activation of DNA damage responses (including p53 phosphorylation), and cell death. In contrast, 10-MeBaP, representing BaP isomers substituted with the methyl group in the angular ring, elicited only low levels DNA adduct formation and apoptosis. Other MeBaPs under study also elicited strong apoptotic responses associated with DNA adduct formation as the prevalent mode of toxic action of these compounds in liver cells. MeBaPs induced a weak production of ROS, which did not lead to significant oxidative DNA damage. Importantly, 1-MeBaP and 3-MeBaP were found to be potent AhR agonists, one order of magnitude more potent than BaP, thus suggesting that the AhR-dependent modulations of gene expression, deregulation of cell survival mechanisms, and further nongenotoxic effects associated with AhR activation may further contribute to their tumor promotion and carcinogenicity.},

note = {Place: United States},

keywords = {Animals, Apoptosis/drug effects, Aryl Hydrocarbon/*metabolism, Benzo(a)pyrene/*chemistry/*toxicity, Cell Cycle/drug effects, Cell Line, Checkpoint Kinase 1, DNA Adducts/metabolism, Epithelial Cells/drug effects/metabolism, Gene Expression Regulation/drug effects, Liver/*cytology, Methylation, Mutagens/*chemistry/*toxicity, Oxidative Stress/drug effects, Protein Kinases/metabolism, Rats, Receptors, Stem Cells/drug effects/metabolism, Tumor, Tumor Suppressor Protein p53/metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{benes_inhibition_2011,

title = {Inhibition of topoisomerase IIα: novel function of wedelolactone.},

author = {Petr Benes and Lucia Knopfova and Filip Trcka and Alice Nemajerova and Diana Pinheiro and Karel Soucek and Miroslav Fojta and Jan Smarda},

doi = {10.1016/j.canlet.2011.01.002},

issn = {1872-7980 0304-3835},

year  = {2011},

date = {2011-04-01},

journal = {Cancer letters},

volume = {303},

number = {1},

pages = {29–38},

abstract = {The naturally occurring coumestan wedelolactone has been previously shown to reduce growth of various cancer cells. So far, the growth-suppressing effect of wedelolactone has been attributed to the inhibition of the NFκB transcription factor and/or androgen receptors. We found that wedelolactone suppressed growth and induced apoptosis of androgen receptor-negative MDA-MB-231 breast cancer cells at concentrations that did not inhibit the NFκB activity. The cells responded to wedelolactone by the S and G2/M phase cell cycle arrest and induction of the DNA damage signaling. Wedelolactone interacted with dsDNA and inhibited the activity of DNA topoisomerase IIα. We conclude that wedelolactone can act as growth suppressor independently of NFκB and androgen receptors.},

note = {Place: Ireland},

keywords = {Antigens, Antineoplastic Agents/pharmacology, Apoptosis/drug effects, Breast Neoplasms/*drug therapy/enzymology/pathology, Cell Cycle/drug effects, Cell Growth Processes/drug effects, Cell Line, Cell Survival/drug effects, Coumarins/*pharmacology, DNA Damage, DNA Topoisomerases, DNA-Binding Proteins/*antagonists & inhibitors/metabolism, Enzyme-Linked Immunosorbent Assay, Female, Humans, Immunoblotting, Neoplasm/metabolism, Signal Transduction, Topoisomerase Inhibitors/*pharmacology, Tumor, Type II/metabolism},

pubstate = {published},

tppubtype = {article}

}

@article{soucek_growthdifferentiation_2010,

title = {Growth/differentiation factor-15 is an abundant cytokine in human seminal plasma.},

author = {Karel Soucek and Eva Slabáková and Petra Ovesná and Alice Malenovská and Alois Kozubík and Ales Hampl},

doi = {10.1093/humrep/deq264},

issn = {1460-2350 0268-1161},

year  = {2010},

date = {2010-12-01},

journal = {Human reproduction (Oxford, England)},

volume = {25},

number = {12},

pages = {2962–2971},

abstract = {BACKGROUND: Transforming growth factor-β cytokines have various biological effects in female reproductive tissue, including modulation of inflammatory response and induction of immune tolerance to seminal antigens in the reproductive tract. However, no studies have analyzed the presence of growth/differentiation factor-15 (GDF-15/macrophage inhibitory cytokine-1) in seminal fluid or demonstrated the quantity and form of GDF-15, its possible role or the relationship between its concentration and semen quality. METHODS: The form and the concentration of GDF-15 were determined in 53 seminal plasma samples of both fertile and infertile men by ELISA and western blot. The sperm cells of three volunteers were treated with recombinant GDF-15, and cell viability and apoptosis were assessed by flow cytometry. The effect of GDF-15 on vaginal epithelial cells and peripheral blood mononuclear cells (PBMCs) was analyzed by quantitative RT-PCR. RESULTS: The GDF-15 concentration in seminal plasma ranged from 0.2 to 6.6 μg/ml as determined by ELISA. Western blot analysis revealed that GDF-15 is present in the active form. In vitro cultivation of sperm cells with GDF-15 did not affect their viability or rates of apoptosis; however, it did inhibit proliferation of PBMCs and induce expression of FOXP3 in CD4+CD25+ cells. CONCLUSIONS: To the best of our knowledge, this is the first demonstration that GDF-15 is an abundant cytokine in seminal plasma, although its concentration is not associated with semen quality or the fertility/infertility status of the donors. Moreover, our data show that GDF-15 displays immunosuppressive characteristics.},

note = {Place: England},

keywords = {Adult, Apoptosis/drug effects, CD4-Positive T-Lymphocytes/metabolism, Cell Proliferation/drug effects, Cell Survival/drug effects, Epithelial Cells/metabolism, Female, Forkhead Transcription Factors/biosynthesis, Growth Differentiation Factor 15/*physiology, Humans, Interleukin-2 Receptor alpha Subunit/metabolism, Leukocytes, Male, Middle Aged, Mononuclear/drug effects, Semen Analysis, Semen/*metabolism, Spermatozoa},

pubstate = {published},

tppubtype = {article}

}

@article{svihalkova-sindlerova_-12_2010,

title = {LA-12 overcomes confluence-dependent resistance of HT-29 colon cancer cells to Pt (II) compounds.},

author = {Lenka Svihálková-Sindlerová and Vendula Foltinová and Alena Vaculová and Viktor Horváth and Karel Soucek and Petr Sova and Jirina Hofmanová and Alois Kozubík},

issn = {1791-7530 0250-7005},

year  = {2010},

date = {2010-04-01},

journal = {Anticancer research},

volume = {30},

number = {4},

pages = {1183–1188},

abstract = {BACKGROUND: LA-12 is a new platinum (IV) drug with promising cytotoxic effects in a wide range of cancer cell lines. Its confluence-dependent effects were compared with cisplatin (CDDP) and oxaliplatin (L-OHP) in HT-29 cells. MATERIALS AND METHODS: Cytotoxicity was determined by MTT test, eosin exclusion assay, and cell number quantification. The cell cycle was analysed using propidium iodide DNA staining (flow cytometry), apoptosis by phosphatidylserine externalisation (annexin-V assay), mitochondrial membrane potential by flow cytometry, nuclear morphology by means of fluorescence microscopy, and PARP cleavage by Western blotting. RESULTS: While L-OHP and CDDP were practically inactive in the subconfluent cell population, LA-12 showed a similar toxicity in both subconfluent and growing populations. All compounds induced apoptosis, although with different potentials. CONCLUSION: LA-12 was able to overcome confluence-dependent resistance of HT-29 cells observed for other platinum compounds, which may have potential therapeutic use in slowly growing tumours.},

note = {Place: Greece},

keywords = {Adenocarcinoma/*drug therapy, Amantadine/*analogs & derivatives/pharmacology, Antineoplastic Agents/*pharmacology, Apoptosis/drug effects, Cell Adhesion/drug effects, Cisplatin/pharmacology, Colonic Neoplasms/*drug therapy/pathology, Dose-Response Relationship, Drug, Drug resistance, HT29 Cells, Humans, Neoplasm, Organoplatinum Compounds/*pharmacology, Oxaliplatin},

pubstate = {published},

tppubtype = {article}

}

@article{ondrouskova_heavy_2009,

title = {Heavy metals induce phosphorylation of the Bcl-2 protein by Jun N-terminal kinase.},

author = {Eva Ondrousková and Jana Slovácková and Vendula Pelková and Jirina Procházková and Karel Soucek and Petr Benes and Jan Smarda},

doi = {10.1515/BC.2009.007},

issn = {1431-6730},

year  = {2009},

date = {2009-01-01},

journal = {Biological chemistry},

volume = {390},

number = {1},

pages = {49–58},

abstract = {The Bcl-2 protein is one of the key components of biochemical pathways controlling programmed cell death. The function of this protein can be regulated by posttranslational modifications. Phosphorylation of Bcl-2 has been considered to be significantly associated with cell cycle arrest in the G2/M phase of the cell cycle, and with cell death caused by defects of microtubule dynamics. This study shows that phosphorylation of Bcl-2 can be induced by heavy metals due to activation of the Jun N-terminal kinase pathway that is not linked to the G2/M cell cycle arrest. Furthermore, we demonstrate that hyperphosphorylated Bcl-2 protein is a more potent inhibitor of zinc-induced cell death than its hypophosphorylated mutant form. These data suggest that regulation of Bcl-2 protein function by phosphorylation is an important part of cell responses to stress.},

note = {Place: Germany},

keywords = {Animals, Apoptosis/drug effects, Cell Line, Electrophoresis, Gene Expression Regulation, Heavy/*pharmacology, Humans, JNK Mitogen-Activated Protein Kinases/*metabolism, Metals, Neoplastic/drug effects, Phosphorylation/drug effects, Physiological/drug effects, Post-Translational/drug effects, Protein Processing, Proto-Oncogene Proteins c-bcl-2/*metabolism, Signal Transduction/drug effects, Stress, Tumor, Zinc/pharmacology},

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{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}

}

@article{chramostova_polycyclic_2004,

title = {Polycyclic aromatic hydrocarbons modulate cell proliferation in rat hepatic epithelial stem-like WB-F344 cells.},

author = {Katerina Chramostová and Jan Vondrácek and Lenka Sindlerová and Borivoj Vojtesek and Alois Kozubík and Miroslav Machala},

doi = {10.1016/j.taap.2003.12.008},

issn = {0041-008X},

year  = {2004},

date = {2004-04-01},

journal = {Toxicology and applied pharmacology},

volume = {196},

number = {1},

pages = {136–148},

abstract = {Although many polycyclic aromatic hydrocarbons (PAHs) are recognized as potent mutagens and carcinogens, relatively little is known about their role in the tumor promotion. It is known that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce release of rat hepatic oval epithelial cells from contact inhibition by a mechanism possibly involving the aryl hydrocarbon receptor (AhR) activation. Many PAHs are AhR ligands and are known to act as transient inducers of AhR-mediated activity. In this study, effects of 19 selected PAHs on proliferation of confluent rat liver epithelial WB-F344 cells were investigated. Non-mutagens that are weak activators or nonactivators of AhR-mediated activity had no effect on cell proliferation. Relatively strong or moderate AhR ligands with low mutagenic potencies, such as benzofluoranthenes, benz[a]anthracene, and chrysene, were found to increase cell numbers, which corresponded to an increased percentage of cells entering S-phase. Strong mutagens, including benzo[a]pyrene and dibenzo[a,l]pyrene, increased a percentage of cells in S-phase without inducing a concomitant increase in cell numbers. The treatment with mutagenic PAHs was associated with an increased DNA synthesis and induction of cell death, which corresponded with the activation of p53 tumor suppressor. Apoptosis was blocked by pifithrin-alpha, the chemical inhibitor of p53. Both weakly and strongly mutagenic PAHs known as AhR ligands were found to induce significant increase of cytochrome P4501A activity, suggesting a presence of functional AhR. The results of the present study seem to suggest that a release from contact inhibition could be a part of tumor promoting effects of AhR-activating PAHs; however, the genotoxic effects of some PAHs associated with p53 activation might interfere with this process.},

note = {Place: United States},

keywords = {Animals, Apoptosis/drug effects, Aryl Hydrocarbon/metabolism, Cell Division/drug effects, Cells, Cultured, Cytochrome P-450 CYP1A1/metabolism, Dose-Response Relationship, Drug, Epithelial Cells/*drug effects/enzymology/metabolism, Liver/*cytology, Mutagens/*toxicity, Polycyclic Aromatic Hydrocarbons/*toxicity, Rats, Receptors, Stem Cells/*drug effects/enzymology/metabolism, Tumor Suppressor Protein p53/biosynthesis},

pubstate = {published},

tppubtype = {article}

}