Latest Publications

@article{prochazkova_monocytic_2009,

title = {Monocytic differentiation of leukemic HL-60 cells induced by co-treatment with TNF-alpha and MK886 requires activation of pro-apoptotic machinery.},

author = {Jirina Procházková and Lenka Stixová and Karel Soucek and Jirina Hofmanová and Alois Kozubík},

doi = {10.1111/j.1600-0609.2009.01240.x},

issn = {1600-0609 0902-4441},

year  = {2009},

date = {2009-07-01},

journal = {European journal of haematology},

volume = {83},

number = {1},

pages = {35–47},

abstract = {The block of hematopoietic differentiation program in acute myeloid leukemia cells can be overcome by differentiating agent like retinoic acid, but it has several side effects. A study of other differentiation signaling pathways is therefore useful to predict potential targets of anti-leukemic therapy. We demonstrated previously that the co-treatment of HL-60 cells with Tumor necrosis factor-alpha (TNF-alpha) (1 ng/mL) and inhibitor of 5-lipoxygenase MK886 (5 microm) potentiated both monocytic differentiation and apoptosis. In this study, we detected enhanced activation of three main types of mitogen-activated protein kinases (MAPKs) (p38, c-Jun amino-terminal kinase [JNK], extracellular signal-regulated kinase [ERK]), so we assessed their role in differentiation using appropriate pharmacologic inhibitors. The inhibition of pro-apoptotic MAPKs (p38 and JNK) suppressed the effect of MK886 + TNF-alpha co-treatment. On the other hand, down-regulation of pro-survival ERK pathway led to increased differentiation. Those effects were accompanied by increased activation of caspases in cells treated by MK886 + TNF-alpha. Pan-caspase inhibitor ZVAD-fmk significantly decreased both number of apoptotic and differentiated cells. The same effect was observed after inhibition of caspase 9, but not caspase 3 and 8. To conclude, we evidenced that the activation of apoptotic processes and pathways supporting apoptosis (p38 and JNK MAPKs) is required for the monocytic differentiation of HL-60 cells.},

note = {Place: England},

keywords = {Acute/*drug therapy/metabolism/*pathology, Amino Acid Chloromethyl Ketones/pharmacology, Apoptosis/*drug effects/physiology, Caspase Inhibitors, Caspases/metabolism, Cell Differentiation/drug effects, Cysteine Proteinase Inhibitors/pharmacology, Enzyme Activation/drug effects, HL-60 Cells, Humans, Indoles/*pharmacology, Leukemia, Lipoxygenase Inhibitors/pharmacology, MAP Kinase Signaling System/drug effects, Monocytes/*drug effects/pathology, NF-kappa B/antagonists & inhibitors, Promyelocytic, Tumor Necrosis Factor-alpha/*pharmacology},

pubstate = {published},

tppubtype = {article}

}

@article{vondracek_dimethyl_2006,

title = {Dimethyl sulfoxide potentiates death receptor-mediated apoptosis in the human myeloid leukemia U937 cell line through enhancement of mitochondrial membrane depolarization.},

author = {Jan Vondrácek and Karel Soucek and Michael A. Sheard and Katerina Chramostová and Zdenek Andrysík and Jirina Hofmanová and Alois Kozubík},

doi = {10.1016/j.leukres.2005.05.016},

issn = {0145-2126},

year  = {2006},

date = {2006-01-01},

journal = {Leukemia research},

volume = {30},

number = {1},

pages = {81–89},

abstract = {Dimethyl sulfoxide (DMSO) is a widely used prototypical chemical inducer of cell differentiation. In the present study, the effects of DMSO on susceptibility of human myeloid leukemia U937 cells towards ligation of distinct death receptors (DRs) were investigated. DMSO sensitized cells towards induction of apoptosis by anti-Fas antibody, tumour necrosis factor-alpha or Apo2 ligand/TNF-related apoptosis-inducing ligand (TRAIL). Apart from increasing Fas levels, DMSO did not affect expression of proteins in death signal transduction, such as Bcl-2 family proteins, FADD, caspase-3 and -8, the inhibitor of apoptosis proteins (IAPs) or cFLIP(L). However, DMSO significantly potentiated mitochondrial membrane depolarization, suggesting that this mechanism might be involved in sensitisation of myeloid cells to DR-mediated apoptosis.},

note = {Place: England},

keywords = {Adaptor Proteins, Apoptosis Regulatory Proteins/*metabolism, Apoptosis/*drug effects, CASP8 and FADD-Like Apoptosis Regulating Protein, Caspase 3, Caspase 8, Caspases/metabolism, Cryoprotective Agents/*pharmacology, Dimethyl Sulfoxide/*pharmacology, fas Receptor/*metabolism, Fas-Associated Death Domain Protein, Humans, Intracellular Signaling Peptides and Proteins, Leukemia, Membrane Glycoproteins/*metabolism, Mitochondria/metabolism/pathology, Mitochondrial Membranes/*metabolism/pathology, Myeloid/*metabolism/pathology, Proto-Oncogene Proteins c-bcl-2/metabolism, Signal Transducing/metabolism, TNF-Related Apoptosis-Inducing Ligand, Tumor Necrosis Factor-alpha/*metabolism, U937 Cells},

pubstate = {published},

tppubtype = {article}

}

@article{vaculova_ethanol_2004,

title = {Ethanol acts as a potent agent sensitizing colon cancer cells to the TRAIL-induced apoptosis.},

author = {Alena Vaculová and Jirina Hofmanová and Karel Soucek and Ladislav Andera and Alois Kozubík},

doi = {10.1016/j.febslet.2004.10.013},

issn = {0014-5793},

year  = {2004},

date = {2004-11-01},

journal = {FEBS letters},

volume = {577},

number = {1-2},

pages = {309–313},

abstract = {Identification of mechanisms of modulation of the TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis is important for its potential use in anticancer therapy. Ethanol can induce cell death in vitro and in vivo by different signalling pathways. Its effect in combination with death ligands is unknown. We investigated how ethanol modulates the effects of TRAIL in colon cancer cells. After combined TRAIL and ethanol treatment, a potentiation of caspase-8, -9, -3 activation, a proapoptotic Bid protein cleavage, a decrease of mitochondrial membrane potential, a complete poly(ADP)ribose polymerase cleavage, and disappearance of antiapoptotic Mcl-1 protein were demonstrated. Ethanol acts as a potent agent sensitizing colon cancer cells to TRAIL-induced apoptosis.},

note = {Place: England},

keywords = {Apoptosis Regulatory Proteins, Apoptosis/*drug effects/physiology, BH3 Interacting Domain Death Agonist Protein, Blotting, Carrier Proteins/metabolism, Caspases/metabolism, Colonic Neoplasms/enzymology/metabolism/*pathology, Ethanol/*pharmacology, HT29 Cells, Humans, Membrane Glycoproteins/*physiology, Myeloid Cell Leukemia Sequence 1 Protein, Neoplasm Proteins/metabolism, Proto-Oncogene Proteins c-bcl-2/metabolism, TNF-Related Apoptosis-Inducing Ligand, Tumor Necrosis Factor-alpha/*physiology, 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}

}