Here, we focus on epigenetic changes in leukaemia and MM (multiple myeloma) cells. We show how the histone signature, DNA methylation and levels of select tumour-suppressor proteins can be affected by inhibitors of HDACs (histone deacetylases) and Dnmts (DNA methyltransferases). Both inhibitors, TSA (trichostatin A) and 5-AZA (5-azacytidine), have the ability to change the histone signature in a tumour-specific manner. In MM cells, we observed changes in H3K4 methylation, while in leukaemia cells, H3K9 methylation was especially affected by select inhibitors. Compared with normal peripheral blood lymphocytes, tumour cell samples were characterized by increased H3K9 acetylation, increased H3K4me2, H3K9me2 and HP1α (heterochromatin protein 1α) levels and specific changes were also observed for DNA methylation. Additionally, we showed that the tumour suppressor pRb1 (retinoblastoma protein) is more sensitive to epigenetic-based anti-cancer stimuli than p53. We have found significant decrease in the levels of pRb1 and p53 in both myeloma and leukaemia cells after HDAC inhibition.
- MeSH
- antitumorózní látky farmakologie MeSH
- azacytidin farmakologie MeSH
- DNA modifikační methylasy genetika metabolismus MeSH
- epigeneze genetická * MeSH
- histondeacetylasy metabolismus MeSH
- histony genetika metabolismus MeSH
- homolog proteinu s chromoboxem 5 MeSH
- inhibitory histondeacetylas farmakologie MeSH
- kyseliny hydroxamové farmakologie MeSH
- leukemie farmakoterapie genetika MeSH
- lidé MeSH
- metylace DNA MeSH
- mnohočetný myelom farmakoterapie genetika MeSH
- nádorový supresorový protein p53 genetika metabolismus MeSH
- retinoblastomový protein genetika metabolismus MeSH
- umlčování genů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antitumorózní látky MeSH
- azacytidin MeSH
- CBX5 protein, human MeSH Prohlížeč
- DNA modifikační methylasy MeSH
- histondeacetylasy MeSH
- histony MeSH
- homolog proteinu s chromoboxem 5 MeSH
- inhibitory histondeacetylas MeSH
- kyseliny hydroxamové MeSH
- nádorový supresorový protein p53 MeSH
- retinoblastomový protein MeSH
- trichostatin A MeSH Prohlížeč
Ultrafiltered pig leukocyte extract (UPLE, Imunor), a heterogeneous mixture of low molecular weight (<10 kD) substances released from disintegrated pig leukocytes was tested from the point of view of its hematopoiesis-modulating activities using experiments in vitro and in vivo. Attention was focused especially on evaluation of the contingent ability of UPLE to potentiate the hematopoiesis-stimulating effects of recobinant human granulocyte colony-stimulating factor (G-CSF). Experiments in vitro revealed the capability of sera from mice administered UPLE perorally (p.o.) to stimulate proliferation of progenitor cells for granulocytes and macrophages (GM-CFC) in cultures of normal bone marrow cells. In addition, UPLE, as well as sera from mice given UPLE, added to the cultures in combination with G-CSF enhanced the numbers of GM-CFC significantly over those induced by sera after administration of either of the preparations alone. In in vivo experiments, UPLE was found to increase the counts of GM-CFC per femur and femoral bone marrow cellularity in sublethally irradiated mice when administered p.o. after irradiation in combination with G-CSF in comparison with the effects of G-CSF alone. These results indicate the possibility of using UPLE, a commercially available preparation, for treatment of hematopoietic suppression of various etiology.
- MeSH
- analýza kolonii tvořících jednotek MeSH
- buněčné extrakty aplikace a dávkování farmakologie MeSH
- buňky kostní dřeně účinky léků účinky záření MeSH
- časové faktory MeSH
- celotělové ozáření MeSH
- faktor stimulující kolonie granulocytů aplikace a dávkování farmakologie MeSH
- filgrastim MeSH
- hematopoetické kmenové buňky účinky léků účinky záření MeSH
- hematopoéza účinky léků účinky záření MeSH
- kultivované buňky MeSH
- leukocyty * chemie imunologie MeSH
- lidé MeSH
- myši MeSH
- prasata MeSH
- radioprotektivní látky aplikace a dávkování farmakologie MeSH
- rekombinantní proteiny MeSH
- synergismus léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- buněčné extrakty MeSH
- faktor stimulující kolonie granulocytů MeSH
- filgrastim MeSH
- radioprotektivní látky MeSH
- rekombinantní proteiny MeSH
Epigenetic changes accompanying plant cell dedifferentiation and differentiation are reported in 35S ribosomal DNA (rDNA) of tobacco (Nicotiana tabacum). There was a reduction of CG and CNG methylation in both intergenic and genic regions of the rDNA cistron in fully dedifferentiated callus and root compared to leaf. The rDNA hypomethylation was not random, but targeted to particular rDNA gene families at units that are clustered within the tandem array. The process of hypomethylation was initiated as early as 2 weeks after the callus induction and established epigenetic patterns were stably maintained throughout prolonged culture. However, regenerated plants and their progeny showed partial and complete remethylation of units, respectively. Nuclear run-on assays revealed a 2-fold increase of primary (unprocessed) ribosomal RNA transcripts in callus compared to leaf tissue. However, the abundance of mature transcripts in callus was elevated by only about 25%. Fluorescence in situ hybridization analysis of interphase nuclei showed high levels of rDNA chromatin condensation in both callus and leaf, with substantially less decondensed rDNA than is observed in meristematic root-tip cells. It is likely that the regions of the rDNA locus showing decondensation correspond to the clusters of hypomethylated units that occur in the tandem array at each locus. The data together indicate that the establishment of pluripotency and cell proliferation occurring with callus induction is associated with enhanced ribosomal RNA gene expression and overall rDNA hypomethylation, but is not associated with material-enhanced relaxation of chromatin structure (decondensation) at rDNA loci.
- MeSH
- buněčná diferenciace * MeSH
- chromatin chemie metabolismus MeSH
- genetická transkripce genetika MeSH
- hybridizace in situ fluorescenční MeSH
- interfáze MeSH
- kořeny rostlin genetika MeSH
- kultivované buňky MeSH
- listy rostlin cytologie genetika MeSH
- messenger RNA genetika metabolismus MeSH
- metylace DNA * MeSH
- regenerace MeSH
- regulace genové exprese u rostlin MeSH
- RNA ribozomální genetika MeSH
- tabák cytologie genetika růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chromatin MeSH
- messenger RNA MeSH
- RNA ribozomální MeSH
1,2-GG intrastrand cross-links formed in DNA by the enantiomeric complexes [PtCl(2)(R,R-2,3-diaminobutane (DAB))] and [PtCl(2)(S,S-DAB)] were studied by biophysical methods. Molecular modeling revealed that structure of the cross-links formed at the TGGT sequence was affected by repulsion between the 5'-directed methyl group of the DAB ligand and the methyl group of the 5'-thymine of the TGGT fragment. Molecular dynamics simulations of the solvated platinated duplexes and our recent structural data indicated that the adduct of [PtCl(2)(R,R-DAB)] alleviated this repulsion by unwinding the TpG step, whereas the adduct of [PtCl(2)(S,S-DAB)] avoided the unfavorable methyl-methyl interaction by decreasing the kink angle. Electrophoretic retardation measurements on DNA duplexes containing 1,2-GG intrastrand cross-links of Pt(R,R-DAB)(2+) or Pt(S,S-DAB)(2+) at a CGGA site showed that in this sequence both enantiomers distorted the double helix to the identical extent similar to that found previously for the same sequence containing the cross-links of the parent antitumor cis-Pt(NH(3))(2)(2+) (cisplatin). In addition, the adducts showed similar affinities toward the high-mobility-group box 1 proteins. Hence, whereas the structural perturbation induced in DNA by 1,2-GG intrastrand cross-links of cisplatin does not depend largely on the bases flanking the cross-links, the perturbation related to GG cross-linking by bulkier platinum diamine derivatives does.
- MeSH
- adukty DNA chemie genetika MeSH
- biofyzika MeSH
- biofyzikální jevy MeSH
- cisplatina analogy a deriváty chemie MeSH
- konformace nukleové kyseliny MeSH
- ligandy MeSH
- molekulární modely MeSH
- protein HMGB1 chemie MeSH
- reagencia zkříženě vázaná MeSH
- retardační test MeSH
- sekvence nukleotidů MeSH
- stereoizomerie MeSH
- techniky in vitro MeSH
- termodynamika MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adukty DNA MeSH
- cisplatin-DNA adduct MeSH Prohlížeč
- cisplatina MeSH
- ligandy MeSH
- protein HMGB1 MeSH
- reagencia zkříženě vázaná MeSH
The development of metal-based antitumor drugs has been stimulated by the clinical success of cis-diamminedichloroplatinum(II) (cisplatin) and its analogs and by the clinical trials of other platinum and ruthenium complexes with activity against resistant tumors and reduced toxicity including orally available platinum drugs. Broadening the spectrum of antitumor drugs depends on understanding existing agents with a view toward developing new modes of attack. It is therefore of great interest to understand the details of molecular and biochemical mechanisms underlying the biological efficacy of platinum and other transition-metal compounds. There is a large body of experimental evidence that the success of platinum complexes in killing tumor cells results from their ability to form various types of covalent adducts on DNA; thus, the research of DNA interactions of metal-based antitumor drugs has predominated. The present review summarizes current knowledge on DNA modifications by platinum and ruthenium complexes, their recognition by specific proteins, and repair. It also provides strong support for the view that either platinum or ruthenium drugs, which bind to DNA in a fundamentally different manner from that of 'classical' cisplatin, have altered pharmacological properties. The present article also demonstrates that this concept has already led to the synthesis of several new unconventional platinum or ruthenium antitumor compounds that violate the original structure-activity relationships.
- MeSH
- adukty DNA účinky léků metabolismus MeSH
- antitumorózní látky chemie farmakologie MeSH
- cisplatina analogy a deriváty farmakologie MeSH
- DNA nádorová účinky léků metabolismus MeSH
- lidé MeSH
- molekulární modely MeSH
- molekulární sekvence - údaje MeSH
- oprava DNA MeSH
- organokovové sloučeniny chemie farmakologie MeSH
- organoplatinové sloučeniny chemie farmakologie MeSH
- protein HMGB1 genetika metabolismus MeSH
- ruthenium farmakologie MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- stereoizomerie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- adukty DNA MeSH
- antitumorózní látky MeSH
- cisplatina MeSH
- DNA nádorová MeSH
- organokovové sloučeniny MeSH
- organoplatinové sloučeniny MeSH
- protein HMGB1 MeSH
- ruthenium MeSH
Pollen grains of angiosperm plants represent a good model system for studies of chromatin structure and remodelling factors, but very little is known about the DNA methylation status of particular genes in pollen. In this study, we present an analysis of the DNA methylation patterns of the MROS1 gene, which is expressed in the late phases of pollen development in Silene latifolia (syn. Meladrium album). The genomic sequencing technique revealed similar DNA methylation patterns in leaves, binucleate pollen, and trinucleate pollen. Extremely high DNA methylation levels occurred in the CG dinucleotides of the upstream region (99%), whereas only a low level of CG methylation was observed in the transcribed sequence (7%). Low levels of methylation were also observed in asymmetric sequences (in both regions; 2% methylated). The results obtained in the MROS1 gene are discussed in consequence with the immunohistochemical data showing a hypermethylation of DNA in the vegetative nucleus.
- MeSH
- DNA rostlinná chemie genetika MeSH
- druhová specificita MeSH
- genom rostlinný MeSH
- imunohistochemie MeSH
- metylace DNA * MeSH
- molekulární sekvence - údaje MeSH
- promotorové oblasti (genetika) MeSH
- pyl chemie genetika růst a vývoj MeSH
- rostlinné geny MeSH
- rostlinné proteiny genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční homologie nukleových kyselin MeSH
- Silene chemie genetika růst a vývoj MeSH
- tkáňová distribuce MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- DNA rostlinná MeSH
- MEN-1 protein, Silene latifolia MeSH Prohlížeč
- rostlinné proteiny MeSH
Highly sensitive label-free techniques of DNA determination are particularly interesting in relation to the present development of the DNA sensors. We show that subnanomolar concentrations (related to monomer content) of unlabeled DNA can be determined using copper solid amalgam electrodes or hanging mercury drop electrodes in the presence of copper. DNA is first treated with acid (e.g., 0.5 M perchloric acid), and the acid-released purine bases are directly determined by the cathodic stripping voltammetry. Volumes of 5-3 microL of acid-treated DNA can easily be analyzed, thus making possible the determination of picogram and subpicogram amounts of DNA corresponding to attomole and subattomole quantities of 1000-base pair DNA. Application of this determination in DNA hybridization detection is demonstrated using surface H for the hybridization (superparamagnetic beads with covalently attached DNA probe) and the mercury electrodes only for the determination of DNA selectively captured at surface H.
- MeSH
- DNA analýza MeSH
- elektrochemie přístrojové vybavení MeSH
- elektrody * MeSH
- hybridizace nukleových kyselin MeSH
- měď * MeSH
- rtuť * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA MeSH
- měď * MeSH
- rtuť * MeSH
Nicotiana tabacum (tobacco, Solanaceae) has two 5S ribosomal DNA (rDNA) families, one of unit length approximately 646 bp and the other -430 bp, that differ in the length of the 5S rDNA non-transcribed spacer (NTS). The long 5S rDNA family, found on the T genome of tobacco and in Nicotiana tomentosiformis, contains a GC-rich subregion that is absent in the short family. We designed primers for this subregion and generated a probe that we used against a range of Nicotiana and related Solanaceous species. We demonstrated the presence of the GC-rich subregion in a range of Nicotiana species, but it was absent in Nicotiana sylvestris, Nicotiana longiflora, and two closely related genera, Petunia and Solanum. These data suggest that this subregion of the NTS is likely to have evolved with the genus Nicotiana. The absence of the subregion in N. sylvestris and N. longiflora is likely to have arisen by a deletion event in the evolution of section alatae. We demonstrate patterns of evolution in the 5S rDNA unit cluster in relation to a phylogenetic reconstruction of species relationships in section tomentosae. Nicotiana glutinosa diverged early from the section and contains a 5S rDNA family based on a 550-bp unit. After this divergence, 430- and 650-bp rDNA unit families evolved. The 650-bp family is found in all species of tomentosae (except N. glutinosa) and in tobacco. The 430-bp family within tomentosae includes the GC-rich subregion and is thus unrelated to the 430-bp family in N. sylvestris. Nicotiana setchellii is unusual in that it has three 5S rDNA loci, including one locus that is exceptionally large. This species, unique to tomentosae, has a very abundant 900-bp unit family. It is possible that this 900-bp family occurs on this one large locus. In N. tomentosa and N. kawakamii, the 650-bp family is predominant, whereas N. tomentosiformis and N. otophora have only the 650-bp family. There is no clear relationship between the number of 5S families and the number of 5S rDNA loci. Certainly the replacement of 5S rDNA units, perhaps by gene conversion, has occurred repeatedly in the evolution of genus Nicotiana.
- MeSH
- DNA rostlinná * MeSH
- fylogeneze MeSH
- GC bohatá sekvence MeSH
- molekulární evoluce * MeSH
- ribozomální DNA * MeSH
- RNA ribozomální 5S genetika MeSH
- Southernův blotting MeSH
- tabák genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA rostlinná * MeSH
- ribozomální DNA * MeSH
- RNA ribozomální 5S MeSH
Genus Silene L. (Caryophyllaceae) contains about 700 species divided into 44 sections. According to recent taxonomic classification this genus also includes taxa previously classified in genera Lychnis and Melandrium. In this work, four Silene species belonging to different sections were studied: S. latifolia (syn. Melandrium album, Section Elisanthe), S. vulgaris (Inflatae), S. pendula (Erectorefractae), and S. chalcedonica (syn. Lychnis chalcedonica, Lychnidiformes). Flow cytometric analysis revealed a genome size of 2.25 and 2.35 pg/2C for S. vulgaris and S. pendula and of 5.73 and 6.59 pg/2C for S. latifolia and S. chalcedonica. All four species have the same chromosome number including the pair of sex chromosomes of the dioecious S. latifolia (2n = 2x = 24). Double target fluorescence in-situ hybridization revealed the chromosomal locations of 25S rDNA and 5S rDNA. A marked variation in number and localization of rDNA loci but no correlation between the numbers of rDNA clusters and genome size was found. FISH and genome size data indicate that nuclear genomes of Silene species are highly diversified as a result of numerous DNA amplifications and translocations.
- MeSH
- buněčné jadérko ultrastruktura MeSH
- buněčné jádro ultrastruktura MeSH
- chromozomy ultrastruktura MeSH
- hybridizace in situ fluorescenční MeSH
- hybridizace in situ MeSH
- modely genetické MeSH
- průtoková cytometrie MeSH
- ribozomální DNA genetika ultrastruktura MeSH
- Silene klasifikace genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ribozomální DNA MeSH
