Latest Publications

@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{valovicova_differences_2009,

title = {Differences in DNA damage and repair produced by systemic, hepatocarcinogenic and sarcomagenic dibenzocarbazole derivatives in a model of rat liver progenitor cells.},

author = {Zuzana Valovicová and Sona Marvanová and Monika Mészárosová and Annamária Srancíková and Lenka Trilecová and Alena Milcová and Helena Líbalová and Jan Vondrácek and Miroslav Machala and Jan Topinka and Alena Gábelová},

doi = {10.1016/j.mrfmmm.2009.02.014},

issn = {0027-5107},

year  = {2009},

date = {2009-06-01},

journal = {Mutation research},

volume = {665},

number = {1-2},

pages = {51–60},

abstract = {Liver progenitor (oval) cells are a potential target cell population for hepatocarcinogens. Our recent study showed that the liver carcinogens 7H-dibenzo[c,g]carbazole (DBC) and 5,9-dimethyldibenzo[c,g]carbazole (DiMeDBC), but not the sarcomagen N-methyldibenzo[c,g]carbazole (N-MeDBC), induced several cellular events associated with tumor promotion in WB-F344 cells, an in vitro model of liver oval cells [J. Vondracek, L. Svihalkova-Sindlerova, K. Pencikova, P. Krcmar, Z. Andrysik, K. Chramostova, S. Marvanova, Z. Valovicova, A. Kozubik, A. Gabelova, M. Machala, 7H-Dibenzo[c,g]carbazole and 5,9-dimethyldibenzo[c,g]carbazole exert multiple toxic events contributing to tumor promotion in rat liver epithelial 'stem-like' cells, Mutat. Res. Fundam. Mol. Mech. Mutagen. 596 (2006) 43-56]. In this study, we focused on the genotoxic effects generated by these dibenzocarbazoles in WB-F344 cells to better understand the cellular and molecular mechanisms involved in hepatocarcinogenesis. Lower IC(50) values determined for DBC and DiMeDBC, as compared with N-MeDBC, indicated a higher sensitivity of WB-F344 cells towards hepatocarcinogens. Accordingly, DBC produced a dose-dependent DNA-adduct formation resulting in substantial inhibition of DNA replication and transcription. In contrast, DNA-adduct number detected in DiMeDBC-exposed cells was almost negligible, whereas N-MeDBC produced a low level of DNA adducts. Although all dibenzocarbazoles significantly increased the level of strand breaks (p<0.05) and micronuclei (p<0.001) after 2-h treatment, differences in the kinetics of strand break rejoining were found. The strand break level in DiMeDBC- and N-MeDBC-exposed cells returned to near the background level within 24h after treatment, whereas a relatively high DNA damage level was detected in DBC-treated cells up to 48h after exposure. Additional breaks detected after incubation of DiMeDBC-exposed WB-F344 cells with a repair-specific endonuclease, along with a nearly 3-fold higher level of reactive oxygen species found in these cells as compared with control, suggest a possible role of oxidative stress in DiMeDBC genotoxicity. We demonstrated qualitative differences in the DNA damage profiles produced by hepatocarcinogens DBC and DiMeDBC in WB-F344 cells. Different lesions may trigger distinct cellular pathways involved in hepatocarcinogenesis. The low amount of DNA damage, together with an efficient repair, may explain the lack of hepatocarcinogenicity of N-MeDBC.},

note = {Place: Netherlands},

keywords = {*DNA Damage, *DNA Repair, Animals, Biological, Carbazoles/*toxicity, Carcinogens/*toxicity, Cell Line, DNA Adducts/metabolism, Experimental/chemically induced, Histones/metabolism, Kinetics, Liver Neoplasms, Liver/cytology/*drug effects/*metabolism, Models, Mutagens/toxicity, Oxidative Stress/drug effects, Rats, Sarcoma, Stem Cells/cytology/*drug effects/*metabolism},

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{vaculova_tumor_2002,

title = {Tumor necrosis factor-alpha induces apoptosis associated with poly(ADP-ribose) polymerase cleavage in HT-29 colon cancer cells.},

author = {Alena Vaculová and Jirina Hofmanova and Karel Soucek and Martina Kovariková and Alois Kozubík},

issn = {0250-7005},

year  = {2002},

date = {2002-06-01},

journal = {Anticancer research},

volume = {22},

number = {3},

pages = {1635–1639},

abstract = {BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is known for its selective cytotoxic activity on tumour cells. We analysed the response of HT-29 human colon carcinoma cells to this cytokine. MATERIALS AND METHODS: After TNF-alpha treatment, cell proliferation, cell cycle, reactive oxygen species (ROS) production (flow cytometry), the amount of apoptotic cells (flow cytometry, fluorescence microscopy), cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3 activity (Western blotting) were detected. RESULTS: TNF-alpha induced a decrease of cell growth and viability, an accumulation of cells in the S-phase of the cell cycle, an increase of subdiploid cell population and nuclear chromatin condensation and fragmentation, but not sooner than 96-120 hours. However, earlier events characteristic of apoptosis occurred, such as caspase-3 activation, PARP cleavage to 89 kDa fragment and changes in ROS production. CONCLUSION: We demonstrated that, in addition to being an early marker of apoptosis, activation of caspase-3 and degradation of PARP may play a causative role in HT-29 cell death induced by TNF-alpha.},

note = {Place: Greece},

keywords = {Apoptosis/*drug effects, Caspase 3, Caspases/metabolism, Cell Death/drug effects, Cell Division/drug effects, HT29 Cells/*drug effects/enzymology/pathology, Humans, Kinetics, Poly(ADP-ribose) Polymerases/*metabolism, Reactive Oxygen Species/metabolism, Tumor Necrosis Factor-alpha/*pharmacology},

pubstate = {published},

tppubtype = {article}

}