Latest Publications

@article{krkoska_deregulation_2021,

title = {Deregulation of signaling pathways controlling cell survival and proliferation in cancer cells alters induction of cytochrome P450 family 1 enzymes.},

author = {Martin Krkoška and Jana Svobodová and Markéta Kabátková and Ondřej Zapletal and Alena Hyršlová Vaculová and Jana Nekvindová and Jan Vondráček},

doi = {10.1016/j.tox.2021.152897},

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

year  = {2021},

date = {2021-09-01},

journal = {Toxicology},

volume = {461},

pages = {152897},

abstract = {Cytochrome P450 family 1 (CYP1) enzymes contribute both to metabolism of xenobiotics and to the control of endogenous levels of ligands of the aryl hydrocarbon receptor (AhR). Their activities, similar to other CYPs, can be altered in tumor tissues. Here, we examined a possible role of proliferative/survival pathways signaling, which is often deregulated in tumor cells, and possible links with p300 histone acetyltransferase (a transcriptional co-activator) in the control of CYP1 expression, focusing particularly on CYP1A1. Using cell models derived from human liver, we observed that the induction of CYP1A1 expression, as well as other CYP1 enzymes, was reduced in exponentially growing cells, as compared with their non-dividing counterparts. The siRNA-mediated inhibition of proliferation/pro-survival signaling pathway effectors (such as β-catenin and/or Hippo pathway effectors YAP/TAZ) increased the AhR ligand-induced CYP1A1 mRNA levels in liver HepaRG cells, and/or in colon carcinoma HCT-116 cells. The activation of proliferative Wnt/β-catenin signaling in HCT-116 cells reduced both the induction of CYP1 enzymes and the binding of p300 to the promoter of CYP1A1 or CYP1B1 genes. These results seem to indicate that aberrant proliferative signaling in tumor cells could suppress induction of CYP1A1 (or other CYP1 enzymes) via competition for p300 binding. This mechanism could be involved in modulation of the metabolism of both endogenous and exogenous substrates of CYP1A1 (and other CYP1 enzymes), with possible further consequences for alterations of the AhR signaling in tumor cells, or additional functional roles of CYP1 enzymes.},

note = {Place: Ireland},

keywords = {AhR, Cancer cells, Cell Line, Cell Proliferation, Cell Proliferation/*physiology, Cell Survival/physiology, Colonic Neoplasms/genetics/*pathology, CYP1 enzymes, Cytochrome P-450 CYP1A1/biosynthesis/*genetics, E1A-Associated p300 Protein/metabolism, Enzyme Induction/physiology, Gene Expression Regulation, HCT116 Cells, Hippo Signaling Pathway/physiology, Humans, Liver/*pathology, Neoplastic, p300, Signal Transduction/physiology, Tumor, Wnt Signaling Pathway/physiology, β-Catenin signaling},

pubstate = {published},

tppubtype = {article}

}

@article{tylichova_butyrate_2018,

title = {Butyrate and docosahexaenoic acid interact in alterations of specific lipid classes in differentiating colon cancer cells.},

author = {Zuzana Tylichová and Josef Slavík and Miroslav Ciganek and Petra Ovesná and Pavel Krčmář and Nicol Straková and Miroslav Machala and Alois Kozubík and Jiřina Hofmanová and Jan Vondráček},

doi = {10.1002/jcb.26641},

issn = {1097-4644 0730-2312},

year  = {2018},

date = {2018-06-01},

journal = {Journal of cellular biochemistry},

volume = {119},

number = {6},

pages = {4664–4679},

abstract = {Docosahexaenoic acid (DHA) and sodium butyrate (NaBt) exhibit a number of interactive effects on colon cancer cell growth, differentiation, or apoptosis; however, the molecular mechanisms responsible for these interactions and their impact on cellular lipidome are still not fully clear. Here, we show that both dietary agents together induce dynamic alterations of lipid metabolism, specific cellular lipid classes, and fatty acid composition. In HT-29 cell line, a model of differentiating colon carcinoma cells, NaBt supported incorporation of free DHA into non-polar lipids and their accumulation in cytoplasmic lipid droplets. DHA itself was not incorporated into sphingolipids; however, it significantly altered representation of individual ceramide (Cer) classes, in particular in combination with NaBt (DHA/NaBt). We observed altered expression of enzymes involved in Cer metabolism in cells treated with NaBt or DHA/NaBt, and exogenous Cer 16:0 was found to promote induction of apoptosis in differentiating HT-29 cells. NaBt, together with DHA, increased n-3 fatty acid synthesis and attenuated metabolism of monounsaturated fatty acids. Finally, DHA and/or NaBt altered expression of proteins involved in synthesis of fatty acids, including elongase 5, stearoyl CoA desaturase 1, or fatty acid synthase, with NaBt increasing expression of caveolin-1 and CD36 transporter, which may further promote DHA incorporation and its impact on cellular lipidome. In conclusion, our results indicate that interactions of DHA and NaBt exert complex changes in cellular lipidome, which may contribute to the alterations of colon cancer cell differentiation/apoptotic responses. The present data extend our knowledge about the nature of interactive effects of dietary fatty acids.},

note = {Place: United States},

keywords = {Apoptosis/*drug effects, Butyrate, Butyrates/*pharmacology, Cell Differentiation/*drug effects, Ceramides, Colon cancer, Colonic Neoplasms/*metabolism/pathology, Docosahexaenoic acid, Docosahexaenoic Acids/*pharmacology, HCT116 Cells, Humans, lipid analyses, Lipid Metabolism/*drug effects, Membrane Lipids/classification/*metabolism, Phospholipids},

pubstate = {published},

tppubtype = {article}

}

@article{paculova_brca1_2017,

title = {BRCA1 or CDK12 loss sensitizes cells to CHK1 inhibitors.},

author = {Hana Paculová and Juraj Kramara and Šárka Šimečková and Radek Fedr and Karel Souček and Ondřej Hylse and Kamil Paruch and Marek Svoboda and Martin Mistrík and Jiří Kohoutek},

doi = {10.1177/1010428317727479},

issn = {1423-0380 1010-4283},

year  = {2017},

date = {2017-10-01},

journal = {Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine},

volume = {39},

number = {10},

pages = {1010428317727479},

abstract = {A broad spectrum of tumors develop resistance to classic chemotherapy, necessitating the discovery of new therapies. One successful strategy exploits the synthetic lethality between poly(ADP-ribose) polymerase 1/2 proteins and DNA damage response genes, including BRCA1, a factor involved in homologous recombination-mediated DNA repair, and CDK12, a transcriptional kinase known to regulate the expression of DDR genes. CHK1 inhibitors have been shown to enhance the anti-cancer effect of DNA-damaging compounds. Since loss of BRCA1 increases replication stress and leads to DNA damage, we tested a hypothesis that CDK12- or BRCA1-depleted cells rely extensively on S-phase-related CHK1 functions for survival. The silencing of BRCA1 or CDK12 sensitized tumor cells to CHK1 inhibitors in vitro and in vivo. BRCA1 downregulation combined with CHK1 inhibition induced excessive amounts of DNA damage, resulting in an inability to complete the S-phase. Therefore, we suggest CHK1 inhibition as a strategy for targeting BRCA1- or CDK12-deficient tumors.},

note = {Place: Netherlands},

keywords = {Animals, BRCA1, BRCA1 Protein/antagonists & inhibitors/*genetics, CDK12, Checkpoint Kinase 1/*genetics, CHK1 inhibitor, Colorectal Neoplasms/drug therapy/*genetics/pathology, Cyclin-Dependent Kinases/antagonists & inhibitors/*genetics, DNA damage response, DNA Damage/drug effects, Drug resistance, Gene Expression Regulation, Gene Silencing, HCT116 Cells, Humans, Mice, Neoplasm/genetics, Neoplastic/drug effects, Poly (ADP-Ribose) Polymerase-1/genetics, Pyrazoles/administration & dosage, Pyrimidines/administration & dosage, Transcription, 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{zapletal_butyrate_2017,

title = {Butyrate alters expression of cytochrome P450 1A1 and metabolism of benzo[a]pyrene via its histone deacetylase activity in colon epithelial cell models.},

author = {Ondřej Zapletal and Zuzana Tylichová and Jiří Neča and Jiří Kohoutek and Miroslav Machala and Alena Milcová and Michaela Pokorná and Jan Topinka and Mary Pat Moyer and Jiřina Hofmanová and Alois Kozubík and Jan Vondráček},

doi = {10.1007/s00204-016-1887-4},

issn = {1432-0738 0340-5761},

year  = {2017},

date = {2017-05-01},

journal = {Archives of toxicology},

volume = {91},

number = {5},

pages = {2135–2150},

abstract = {Butyrate, a short-chain fatty acid produced by fermentation of dietary fiber, is an important regulator of colonic epithelium homeostasis. In this study, we investigated the impact of this histone deacetylase (HDAC) inhibitor on expression/activity of cytochrome P450 family 1 (CYP1) and on metabolism of carcinogenic polycyclic aromatic hydrocarbon, benzo[a]pyrene (BaP), in colon epithelial cells. Sodium butyrate (NaBt) strongly potentiated the BaP-induced expression of CYP1A1 in human colon carcinoma HCT116 cells. It also co-stimulated the 7-ethoxyresorufin-O-deethylase (EROD) activity induced by the 2,3,7,8-tetrachlorodibenzo-p-dioxin, a prototypical ligand of the aryl hydrocarbon receptor. Up-regulation of CYP1A1 expression/activity corresponded with an enhanced metabolism of BaP and formation of covalent DNA adducts. NaBt significantly potentiated CYP1A1 induction and/or metabolic activation of BaP also in other human colon cell models, colon adenoma AA/C1 cells, colon carcinoma HT-29 cells, or in NCM460D cell line derived from normal colon mucosa. Our results suggest that the effects of NaBt were due to its impact on histone acetylation, because additional HDAC inhibitors (trichostatin A and suberanilohydroxamic acid) likewise increased both the induction of EROD activity and formation of covalent DNA adducts. NaBt-induced acetylation of histone H3 (at Lys14) and histone H4 (at Lys16), two histone modifications modulated during activation of CYP1A1 transcription, and it reduced binding of HDAC1 to the enhancer region of CYP1A1 gene. This in vitro study suggests that butyrate, through modulation of histone acetylation, may potentiate induction of CYP1A1 expression, which might in turn alter the metabolism of BaP within colon epithelial cells.},

note = {Place: Germany},

keywords = {Benzo(a)pyrene/metabolism/*pharmacokinetics, beta Catenin/metabolism, Butyrate, Butyric Acid/*pharmacology, Colon epithelial cells, Colon/*drug effects/metabolism, CYP1A1, Cytochrome P-450 CYP1A1/genetics/*metabolism, DNA adducts, DNA Adducts/drug effects/metabolism, Enhancer Elements, Genetic/drug effects, HCT116 Cells, Histone Deacetylase 1/antagonists & inhibitors/metabolism, Histone Deacetylase Inhibitors/pharmacology, Histone deacetylases, Histones/metabolism, HT29 Cells, Humans, Inactivation, Metabolic, Polycyclic aromatic hydrocarbons},

pubstate = {published},

tppubtype = {article}

}

@article{tylichova_activation_2017,

title = {Activation of autophagy and PPARγ protect colon cancer cells against apoptosis induced by interactive effects of butyrate and DHA in a cell type-dependent manner: The role of cell differentiation.},

author = {Zuzana Tylichová and Nicol Straková and Jan Vondráček and Alena Hyršlová Vaculová and Alois Kozubík and Jiřina Hofmanová},

doi = {10.1016/j.jnutbio.2016.09.006},

issn = {1873-4847 0955-2863},

year  = {2017},

date = {2017-01-01},

journal = {The Journal of nutritional biochemistry},

volume = {39},

pages = {145–155},

abstract = {The short-chain and n-3 polyunsaturated fatty acids exhibit anticancer properties, and they may mutually interact within the colon. However, the molecular mechanisms of their action in colon cancer cells are still not fully understood. Our study focused on the mechanisms responsible for the diverse effects of sodium butyrate (NaBt), in particular when interacting with docosahexaenoic acid (DHA), in distinct colon cancer cell types, in which NaBt either induces cell differentiation or activates programmed cell death involving mitochondrial pathway. NaBt activated autophagy both in HT-29 cells, which are sensitive to induction of differentiation, and in nondifferentiating HCT-116 cells. However, autophagy supported cell survival only in HT-29 cells. Combination of NaBt with DHA-promoted cell death, especially in HCT-116 cells and after longer time intervals. The inhibition of autophagy both attenuated differentiation and enhanced apoptosis in HT-29 cells treated with NaBt and DHA, but it had no effect in HCT-116 cells. NaBt, especially in combination with DHA, activated PPARγ in both cell types. PPARγ silencing decreased differentiation and increased apoptosis only in HT-29 cells, therefore we verified the role of caspases in apoptosis, differentiation and also PPARγ activity using a pan-caspase inhibitor. In summary, our data suggest that diverse responses of colon cancer cells to fatty acids may rely on their sensitivity to differentiation, which may in turn depend on distinct engagement of autophagy, caspases and PPARγ. These results contribute to understanding of mechanisms underlying differential effects of NaBt, when interacting with other dietary fatty acids, in colon cancer cells.},

note = {Place: United States},

keywords = {Antineoplastic Agents/pharmacology, Apoptosis/*drug effects, Autophagy, Autophagy/*drug effects, Butyrate, Butyrates/*pharmacology, Butyric Acid/pharmacology, Caspase 3/genetics/metabolism, Cell Differentiation/drug effects, Colon cancer, Colonic Neoplasms/*pathology, Differentiation, Docosahexaenoic acid, Docosahexaenoic Acids/*pharmacology, HCT116 Cells, HT29 Cells, Humans, Mitochondria/drug effects/metabolism, PPAR gamma/genetics/*metabolism, PPARγ},

pubstate = {published},

tppubtype = {article}

}

@article{soucek_fetal_2010,

title = {Fetal colon cell line FHC exhibits tumorigenic phenotype, complex karyotype, and TP53 gene mutation.},

author = {Karel Soucek and Pavla Gajdusková and Marie Brázdová and Martina Hýzd'alová and Lenka Kocí and David Vydra and Radek Trojanec and Zuzana Pernicová and Lenka Lentvorská and Marián Hajdúch and Jirina Hofmanová and Alois Kozubík},

doi = {10.1016/j.cancergencyto.2009.11.009},

issn = {1873-4456 0165-4608},

year  = {2010},

date = {2010-03-01},

journal = {Cancer genetics and cytogenetics},

volume = {197},

number = {2},

pages = {107–116},

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

note = {Place: United States},

keywords = {*Genes, Animals, Apoptosis/physiology, Carcinoembryonic Antigen/metabolism, Cell Adhesion/physiology, Cell Growth Processes/physiology, Cell Line, Cell Transformation, Colon/cytology/metabolism/*physiology, Colonic Neoplasms/*genetics/*pathology, Comparative Genomic Hybridization, Cytogenetic Analysis/methods, DNA Damage, DNA Mutational Analysis/methods, Female, Fetus/cytology, Fluorescence, HCT116 Cells, Humans, In Situ Hybridization, Karyotyping, Keratins/metabolism, Mice, Neoplasm Transplantation, Neoplastic/genetics/pathology, p53, Phenotype, Proto-Oncogene Mas, SCID, Signal Transduction, Transformed},

pubstate = {published},

tppubtype = {article}

}