Latest Publications

@article{soucek_transforming_2006,

title = {Transforming growth factor-beta1 inhibits all-trans retinoic acid-induced apoptosis.},

author = {Karel Soucek and Jirí Pacherník and Lukás Kubala and Jan Vondrácek and Jirina Hofmanová and Alois Kozubík},

doi = {10.1016/j.leukres.2005.09.007},

issn = {0145-2126},

year  = {2006},

date = {2006-05-01},

journal = {Leukemia research},

volume = {30},

number = {5},

pages = {607–623},

abstract = {The interaction between retinoids and transforming growth factor-beta1 (TGF-beta1) leading to regulation of proliferation, differentiation and apoptosis is not still fully understood. In this study, we demonstrated that a combination treatment with all-trans retinoic acid (ATRA) and TGF-beta1 led to the enhancement of ATRA-induced suppression of cell proliferation, which is accompanied by inhibition of ATRA-induced apoptosis in human leukemia HL-60 cells. This effect was preceded by the arrest of cells in G0/G1 cell cycle phase linked with pRb protein dephosphorylation, continuous accumulation of p21 and transiently increased level of p27, inhibitors of cyclin-dependent kinases. Inhibition of ATRA-induced apoptosis by TGF-beta1 was associated with an increased level of Mcl-1 protein, an anti-apoptotic member of Bcl-2 family, but not with inhibition of mitochondrial membrane depolarization. Levels of other Bcl-2 family proteins (Bcl-2, Bcl-X(L), Bad, Bak, Bax) were unaffected by simultaneous ATRA and TGF-beta1 treatment, when compared to ATRA alone. Upregulation of c-FLIP(L) protein, an inhibitor of apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), correspond with inhibition of ATRA-induced (autocrine TRAIL-mediated) caspase-8 activation and apoptosis. These results suggest that apoptosis inhibition associated with proliferation block could depend on modulation of the TRAIL apoptotic pathway and regulation of the Mcl-1 protein level. In summary, we demonstrate that the balance of processes leading to regulation of proliferation and differentiation of myeloid cells can modulate cell sensitivity to apoptosis-inducing stimuli.},

note = {Place: England},

keywords = {Apoptosis Regulatory Proteins/metabolism/pharmacology, Apoptosis/*drug effects/physiology, bcl-2-Associated X Protein/drug effects/metabolism, CASP8 and FADD-Like Apoptosis Regulating Protein, Caspase 3, Caspase 8, Caspases/drug effects/metabolism, CD11b Antigen/biosynthesis/drug effects, Cell Cycle/drug effects, Cell Differentiation/drug effects, Cell Proliferation/drug effects, Cell Survival/drug effects, Cultured, Cyclin-Dependent Kinase Inhibitor p21/biosynthesis/drug effects, Drug Synergism, Enzyme Activation/drug effects, G1 Phase/drug effects, Granulocytes/drug effects/physiology, HL-60 Cells, Humans, Intracellular Signaling Peptides and Proteins/drug effects/metabolism, Membrane Glycoproteins/metabolism/pharmacology, Mitochondrial Membranes/drug effects/physiology, Myeloid Cell Leukemia Sequence 1 Protein, Neoplasm Proteins/drug effects/metabolism, Phosphorylation, Proto-Oncogene Proteins c-bcl-2/drug effects/metabolism, Reactive Oxygen Species/metabolism, Resting Phase, Retinoblastoma Protein/drug effects/metabolism, TNF-Related Apoptosis-Inducing Ligand, Transforming Growth Factor beta/*pharmacology, Transforming Growth Factor beta1, Tretinoin/*antagonists & inhibitors/pharmacology, Tumor Cells, Tumor Necrosis Factor-alpha/metabolism/pharmacology},

pubstate = {published},

tppubtype = {article}

}

@article{kovarikova_effects_2004,

title = {The effects of TNF-alpha and inhibitors of arachidonic acid metabolism on human colon HT-29 cells depend on differentiation status.},

author = {Martina Kovaríková and Jirina Hofmanová and Karel Soucek and Alois Kozubík},

doi = {10.1111/j.1432-0436.2004.07201006.x},

issn = {0301-4681},

year  = {2004},

date = {2004-02-01},

journal = {Differentiation; research in biological diversity},

volume = {72},

number = {1},

pages = {23–31},

abstract = {The level of differentiation could influence sensitivity of colonic epithelial cells to various stimuli. In our study, the effects of TNF-alpha, inhibitors of arachidonic acid (AA) metabolism (baicalein, BA; indomethacin, INDO; niflumic acid, NA; nordihydroguaiaretic acid, NDGA), and/or their combinations on undifferentiated or sodium butyrate (NaBt)-differentiated human colon adenocarcinoma HT-29 cells were compared. NaBt-treated cells became growth arrested (blocked in G0/G1 phase of the cell cycle), and showed down-regulated Bcl-xL and up-regulated Bak proteins and increased expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). These cells were more perceptive to anti-proliferative and apoptotic effects of TNF-alpha. Both inhibitors of LOX (BA and NDGA) and COX (INDO and NA) in higher concentrations modulated cell cycle changes accompanying NaBt-induced differentiation and induced various level of cell death in undifferentiated and differentiated cells. Most important is our finding that TNF-alpha action on proliferation and cell death can be potentiated by co-treatment of cells with AA metabolism inhibitors, and that these effects were more significant in undifferentiated cells. TNF-alpha and INDO co-treatment was associated with accumulation of cells in G0/G1 cell cycle phase, increased reactive oxygen species production, and elevated caspase-3 activity. These results indicate the role of differentiation status in the sensitivity of HT-29 cells to the anti-proliferative and proapoptotic effects of TNF-alpha, AA metabolism inhibitors, and their combinations, and imply promising possibility for novel anti-cancer strategies.},

note = {Place: England},

keywords = {*Flavanones, Adenocarcinoma/drug therapy/pathology, Arachidonate 5-Lipoxygenase/metabolism, Arachidonic Acid/*metabolism, Butyrates/pharmacology, Caspase 3, Caspases/drug effects/metabolism, Cell Cycle/drug effects, Cell Differentiation/*drug effects, Cell Division/drug effects, Colonic Neoplasms/drug therapy/metabolism/pathology, Cyclooxygenase 2, Cyclooxygenase 2 Inhibitors, Cyclooxygenase Inhibitors/*pharmacology, Drug Synergism, Flavonoids/pharmacology, HT29 Cells/drug effects, Humans, Indomethacin/pharmacology, Isoenzymes/antagonists & inhibitors/metabolism, Lipoxygenase Inhibitors/*pharmacology, Masoprocol/pharmacology, Membrane Proteins, Niflumic Acid/pharmacology, Prostaglandin-Endoperoxide Synthases/metabolism, Tumor Necrosis Factor-alpha/*pharmacology},

pubstate = {published},

tppubtype = {article}

}