Although TGF-beta1 unambiguously functions as a regulator of hematopoietic differentiation, its significance for the development of myeloid lineage is still questionable. In this study three components of early response to TGF-beta1 treatment were investigated in human promyelocytic leukemia HL-60 cells. Changes in junB mRNA accumulation and pRb dephosphorylation were accompained by accumulation of cells in G1 phase of the cell cycle. Time dependence of these changes may implicate mutual cooperation of the pRb and junB in the cell cycle control. It can be concluded that, although myeloid HL-60 cells are known to require rather complex cytokine stimulation to fully differentiate, they clearly possess the ability to respond to TGF-beta1.

• MeSH
• fosforylace MeSH
• G1 fáze * MeSH
• HL-60 buňky MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• protoonkogenní proteiny c-jun genetika   MeSH
• retinoblastomový protein metabolismus   MeSH
• transformující růstový faktor beta farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• protoonkogenní proteiny c-jun MeSH
• retinoblastomový protein MeSH
• transformující růstový faktor beta MeSH

Sarcomas represent an extensive group of divergent malignant diseases, with the only common characteristic of being derived from mesenchymal cells. As such, sarcomas are by definition very heterogeneous, and this heterogeneity does not manifest only upon intertumoral comparison on a bulk tumor level but can be extended to intratumoral level. Whereas part of this intratumoral heterogeneity could be understood in terms of clonal genetic evolution, an essential part includes a hierarchical relationship between sarcoma cells, governed by both genetic and epigenetic influences, signals that sarcoma cells are exposed to, and intrinsic developmental programs derived from sarcoma cells of origin. The notion of this functional hierarchy operating within each tumor implies the existence of sarcoma stem cells, which may originate from mesenchymal stem cells, and indeed, mesenchymal stem cells have been used to establish several crucial experimental sarcoma models and to trace down their respective stem cell populations. Mesenchymal stem cells themselves are heterogeneous, and, moreover, there are alternative possibilities for sarcoma cells of origin, like neural crest-derived stem cells, or mesenchymal committed precursor cells, or - in rhabdomyosarcoma - muscle satellite cells. These various origins result in substantial heterogeneity in possible sarcoma initiation. Genetic and epigenetic changes associated with sarcomagenesis profoundly impact the biology of sarcoma stem cells. For pediatric sarcomas featuring discrete reciprocal translocations and largely stable karyotypes, the translocation-activated oncogenes could be crucial factors that confer stemness, principally by modifying transcriptome and interfering with normal epigenetic regulation; the most extensively studied examples of this process are myxoid/round cell liposarcoma, Ewing sarcoma, and synovial sarcoma. For adult sarcomas, which have typically complex and unstable karyotypes, stemness might be defined more operationally, as a reflection of actual assembly of genetically and epigenetically conditioned stemness factors, with dedifferentiated liposarcoma providing a most thoroughly studied example. Alternatively, stemness can be imposed by tumor microenvironment, as extensively documented in osteosarcoma. In spite of this heterogeneity in both sarcoma initiation and underlying stemness biology, some of the molecular mechanisms of stemness might be remarkably similar in diverse sarcoma types, like abrogation of classical tumor suppressors pRb and p53, activation of Sox-2, or inhibition of canonical Wnt/β-catenin signaling. Moreover, even some stem cell markers initially characterized for their stem cell enrichment capacity in various carcinomas or leukemias seem to function quite similarly in various sarcomas. Understanding the biology of sarcoma stem cells could significantly improve sarcoma patient clinical care, leading to both better patient stratification and, hopefully, development of more effective therapeutic options.

• Klíčová slova
• Chondrosarcoma, Dickkopf, Ewing sarcoma, Genetic and epigenetic plasticity, In vitro sarcoma progression models, Liposarcoma, Mesenchymal stem cells, Osteosarcoma, Sarcoma, Sarcoma cells of origin, Sarcoma stem cells, Sox-2, Synovial sarcoma, Wnt/β-catenin pathway, p53, pRb,
• MeSH
• epigeneze genetická MeSH
• Ewingův sarkom MeSH
• kmenové buňky cytologie   MeSH
• lidé MeSH
• sarkom patologie   MeSH
• synoviom MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Topoisomerase IIalpha (topo IIalpha) is a nuclear enzyme involved in several critical processes, including chromosome replication, segregation and recombination. Previously we have shown that chromosomal protein HMGB1 interacts with topo IIalpha, and stimulates its catalytic activity. Here we show the effect of HMGB1 on the activity of the human topo IIalpha gene promoter in different cell lines. We demonstrate that HMGB1, but not a mutant of HMGB1 incapable of DNA bending, up-regulates the activity of the topo IIalpha promoter in human cells that lack functional retinoblastoma protein pRb. Transient over-expression of pRb in pRb-negative Saos-2 cells inhibits the ability of HMGB1 to activate the topo IIalpha promoter. The involvement of HMGB1 and its close relative, HMGB2, in modulation of activity of the topo IIalpha gene is further supported by knock-down of HMGB1/2, as evidenced by significantly decreased levels of topo IIalpha mRNA and protein. Our experiments suggest a mechanism of up-regulation of cellular expression of topo IIalpha by HMGB1/2 in pRb-negative cells by modulation of binding of transcription factor NF-Y to the topo IIalpha promoter, and the results are discussed in the framework of previously observed pRb-inactivation, and increased levels of HMGB1/2 and topo IIalpha in tumors.

• MeSH
• aktivace transkripce MeSH
• antigeny nádorové biosyntéza   genetika   MeSH
• DNA vazebné proteiny biosyntéza   genetika   MeSH
• DNA-topoisomerasy typu II biosyntéza   genetika   MeSH
• DNA chemie   metabolismus   MeSH
• faktor vázající CCAAT metabolismus   MeSH
• lidé MeSH
• mutageneze MeSH
• nádorové buněčné linie MeSH
• promotorové oblasti (genetika) MeSH
• protein HMGB1 chemie   genetika   metabolismus   MeSH
• protein HMGB2 metabolismus   MeSH
• retinoblastomový protein metabolismus   MeSH
• senioři MeSH
• upregulace * MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny nádorové MeSH
• DNA vazebné proteiny MeSH
• DNA-topoisomerasy typu II MeSH
• DNA MeSH
• faktor vázající CCAAT MeSH
• protein HMGB1 MeSH
• protein HMGB2 MeSH
• retinoblastomový protein MeSH

Resistance development and exhaustion of the arsenal of existing antibacterial agents urgently require an alternative approach toward drug discovery. Herein, we report the screening of Medicines for Malaria Venture (MMV) Pandemic Response Box (PRB) through a cascade developed to streamline the potential compounds with antivirulent properties to combat an opportunistic pathogen, Pseudomonas aeruginosa. To find an agent suppressing the production of P. aeruginosa virulence factors, we assessed the potential of the compounds in PRB with quorum sensing inhibitory activity. Our approach led us to identify four compounds with significant inhibition of extracellular virulence factor production and biofilm formation. This provides an opportunity to expand and redirect the application of these data sets toward the development of a drug with unexplored target-based activity. IMPORTANCE The rise of drug-resistant pathogens as well as overuse and misuse of antibiotics threatens modern medicine as the number of effective antimicrobial drugs steadily decreases. Given the nature of antimicrobial resistance development under intense selective pressure such as the one posed by pathogen-eliminating antibiotics, new treatment options which could slow down the emergence of resistance are urgently needed. Antivirulence therapy aims at suppressing a pathogen's ability to cause disease rather than eliminating it, generating significantly lower selective pressure. Quorum sensing inhibitors are thought to be able to downregulate the production of virulence factors, allowing for smaller amounts of antimicrobials to be used and thus preventing the emergence of resistance. The PRB constitutes an unprecedented opportunity to repurpose new as well as known compounds with cytotoxicity and in vitro absorption, distribution, metabolism and excretion (ADME) profile available, thus shortening the time between compound discovery and medicinal use.

• Klíčová slova
• Pandemic Response Box, Pseudomonas aeruginosa, antivirulence activity, biofilm inhibition, quorum sensing inhibition,
• MeSH
• antibakteriální látky farmakologie   metabolismus   MeSH
• biofilmy * MeSH
• faktory virulence metabolismus   MeSH
• pandemie MeSH
• Pseudomonas aeruginosa * MeSH
• quorum sensing MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• faktory virulence MeSH

The sensitivity and specificity of the developed anti-HIV1/2 third generation enzyme immunoassay, the IEA-HIV1/2-III, was examined. The test system for the detection of anti-HIV antibodies included peroxidase-conjugated HIV-specific recombinant Gag protein fragments (epitopes of p24 and p17 proteins), Env-1 (epitopes of p41 and p120 proteins), and Env-2 (p36 epitopes). Sensitivity was evaluated with 346 sera from HIV1-seropositive subjects, Anti-HIV1 Low Titer panels no. 10 and PRB-106 and seropositive panel PRB-931 in comparison with other third- and second-generation assays. The IEA-HIV1/2-III assays are characterized with high sensitivity comparable to the other third generation assays and the better sensitivity with respect to the second generation test-kit to determine HIV-specific antibodies in human sera. The specificity was determined using three hundred sixty-seven potentially cross-reactive samples (but negative for anti-HIV1/2). Only one specimen among them was reactive by IEA-HIV1/2-III.

• MeSH
• epitopy MeSH
• HIV antigeny MeSH
• HIV protilátky krev   MeSH
• HIV-1 imunologie   MeSH
• HIV-2 imunologie   MeSH
• imunoenzymatické techniky metody   statistika a číselné údaje   MeSH
• lidé MeSH
• senzitivita a specificita MeSH
• těhotenství MeSH
• zkřížené reakce MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Názvy látek
• epitopy MeSH
• HIV antigeny MeSH
• HIV protilátky MeSH

Therapeutic vaccines against tumors associated with human papillomaviruses (HPV) should elicit cellular immune responses against early HPV antigens, primarily the oncoproteins E7 and E6. Because of safety concerns, the direct use of an unmodified oncogene is impossible in human DNA vaccination. Therefore, we introduced three point mutations into the pRb-binding site of HPV16 E7 oncogene to eliminate its transformation potential. The resultant gene was denoted E7GGG. The rates of expression and the cellular localization of E7 and E7GGG proteins were comparable. In immunization-challenge experiments, the efficacy of plasmids containing the E7, E7GGG, or fusion genes of HPV16 E7, viz. L1DeltaCE7(1-60) (M. Muller et al., 1997, Virology 234, 93-111), and Sig/E7/LAMP-1 (T. C. Wu et al., 1995, Proc. Natl. Acad. Sci. USA 92, 11671-11675), was compared. While tumors developed in all animals immunized with the wild-type E7 gene, a significant proportion of mice remained tumor-free after vaccination with the E7GGG gene. The fusion gene L1DeltaCE7(1-60) induced negligible protection, but Sig/E7/LAMP-1 conferred the highest protection. Intradermal immunization by gene gun proved superior to i.m. inoculation. In "therapeutic" experiments, a 1-day delay between inoculation of oncogenic cells and the start of DNA immunization resulted in partial therapeutic effect, but a 3-day delay produced a substantially lower immunization effect. A combination of Sig/E7/LAMP-1 and E7GGG genes did not enhance the immune response. These results demonstrate a significant enhancement of HPV16 E7 immunogenicity after mutagenesis of the pRb-binding site, but the mutated E7 gene did not excel the Sig/E7/LAMP-1 fusion gene.

• MeSH
• aplikace kožní MeSH
• bodová mutace MeSH
• časové faktory MeSH
• DNA vakcíny aplikace a dávkování   imunologie   MeSH
• experimentální nádory prevence a kontrola   MeSH
• infekce onkogenními viry prevence a kontrola   MeSH
• infekce papilomavirem prevence a kontrola   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• onkogenní proteiny virové genetika   imunologie   MeSH
• Papillomaviridae genetika   imunologie   MeSH
• Papillomavirus E7 - proteiny MeSH
• vakcinace MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• DNA vakcíny MeSH
• oncogene protein E7, Human papillomavirus type 16 MeSH Prohlížeč
• onkogenní proteiny virové MeSH
• Papillomavirus E7 - proteiny MeSH

An electrochemical biosensor for detection of the plant hormone cytokinin is introduced. Cytokinin homeostasis in tissues of many lower and higher plants is controlled largely by the activity of cytokinin dehydrogenase (CKX, EC 1.5.99.12) that catalyzes an irreversible cleavage of N(6)-side chain of cytokinins. Expression of Arabidopsis thaliana CKX2 from Pichia pastoris was used to prepare purified AtCKX2 as the basis of the cytokinin biosensor. Prussian Blue (PrB) was electrodeposited on Pt microelectrodes prior to deposition of the enzyme in a sol-gel matrix. The biosensor gave amperometric responses to several cytokinins. These responses depended on the presence of both the enzyme and the Prussian Blue. Thus Prussian Blue must act as an electron mediator between the FAD centre in CKX2 and the Pt surface.

• MeSH
• Arabidopsis enzymologie   MeSH
• biosenzitivní techniky metody   MeSH
• cytokininy analýza   MeSH
• elektrochemické techniky metody   MeSH
• ferrokyanidy chemie   MeSH
• mikroelektrody MeSH
• oxidoreduktasy genetika   metabolismus   MeSH
• Pichia metabolismus   MeSH
• platina chemie   MeSH
• pokovování galvanické MeSH
• rekombinantní proteiny genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokinin oxidase MeSH Prohlížeč
• cytokininy MeSH
• ferric ferrocyanide MeSH Prohlížeč
• ferrokyanidy MeSH
• oxidoreduktasy MeSH
• platina MeSH
• rekombinantní proteiny MeSH

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.

• MeSH
• apoptóza účinky léků   MeSH
• benz(a)anthraceny toxicita   MeSH
• benzopyren toxicita   MeSH
• buněčné linie MeSH
• buněčný cyklus účinky léků   fyziologie   MeSH
• cyklin A metabolismus   MeSH
• cyklin-dependentní kinasa 2 metabolismus   MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• epitelové buňky cytologie   účinky léků   metabolismus   MeSH
• exprese genu účinky léků   MeSH
• fluoreny toxicita   MeSH
• hepatocyty cytologie   účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• malá interferující RNA genetika   MeSH
• messenger RNA genetika   metabolismus   MeSH
• multiproteinové komplexy MeSH
• mutace MeSH
• mutageny toxicita   MeSH
• polycyklické aromatické uhlovodíky toxicita   MeSH
• proliferace buněk účinky léků   MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• receptory aromatických uhlovodíků antagonisté a inhibitory   genetika   metabolismus   MeSH
• sekvence nukleotidů MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• benz(a)anthracene MeSH Prohlížeč
• benz(a)anthraceny MeSH
• benzo(b)fluoranthene MeSH Prohlížeč
• benzopyren MeSH
• Cdk2 protein, rat MeSH Prohlížeč
• cyklin A MeSH
• cyklin-dependentní kinasa 2 MeSH
• cytochrom P-450 CYP1A1 MeSH
• fluoreny MeSH
• malá interferující RNA MeSH
• messenger RNA MeSH
• multiproteinové komplexy MeSH
• mutageny MeSH
• polycyklické aromatické uhlovodíky MeSH
• proteiny buněčného cyklu MeSH
• receptory aromatických uhlovodíků MeSH

The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of tumour suppressor genes pRb and PTEN and also the natural inhibitors of cyclin dependent kinases - proteins p21(Waf1/Cip1) and p27(Kip1). Attention is also given to the role of FAS-mediated pathways in apoptosis induction.

• MeSH
• antigeny CD95 genetika   fyziologie   MeSH
• apoptóza fyziologie   MeSH
• fosfohydroláza PTEN genetika   fyziologie   MeSH
• inhibiční proteiny cyklin-dependentních kinas genetika   fyziologie   MeSH
• lidé MeSH
• nádorové supresorové proteiny genetika   fyziologie   MeSH
• nádory prostaty genetika   patofyziologie   MeSH
• nádory závislé na hormonech patofyziologie   MeSH
• prognóza MeSH
• progrese nemoci MeSH
• proteinkinasa CDC2 genetika   fyziologie   MeSH
• retinoblastomový protein genetika   fyziologie   MeSH
• supresorové geny fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antigeny CD95 MeSH
• fosfohydroláza PTEN MeSH
• inhibiční proteiny cyklin-dependentních kinas MeSH
• nádorové supresorové proteiny MeSH
• proteinkinasa CDC2 MeSH
• retinoblastomový protein MeSH

Eukaryotic gene expression requires that all the steps of messenger RNA production are regulated in concert to integrate the diverse inputs cells receive. We discuss the functioning of SNW/SKIP, an essential spliceosomal component and transcriptional coregulator, which may provide regulatory coupling of transcription initiation and splicing. SNW/SKIP potentiates the activity of important transcription factors, such as vitamin D receptor, CBF1 (RBP-Jkappa), Smad2/3, and MyoD. It synergizes with Ski in overcoming pRb-mediated cell cycle arrest, and it is targeted by the viral transactivators EBNA2 and E7. SNW/SKIP may aid in conformational transition of the gene expression machine through its avidity to nuclear matrix fractions or by recruiting foldases such as the prolyl isomerase PPIL1. The extensive list of SNW/SKIP partners, its unique primary structure, conserved from yeast to humans, and its essential character suggest a distinct function of general importance.

• MeSH
• aktivace transkripce * MeSH
• DNA vazebné proteiny fyziologie   MeSH
• genetická transkripce genetika   MeSH
• jaderné proteiny fyziologie   MeSH
• koaktivátory jaderných receptorů MeSH
• lidé MeSH
• regulace genové exprese * MeSH
• sestřih RNA MeSH
• signální transdukce * MeSH
• terciární struktura proteinů MeSH
• trans-aktivátory fyziologie   MeSH
• transkripční faktory MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• jaderné proteiny MeSH
• koaktivátory jaderných receptorů MeSH
• SNW1 protein, human MeSH Prohlížeč
• trans-aktivátory MeSH
• transkripční faktory MeSH