In the present study, nickel(II) complex with 2-[2-[2-(1H-benzimidazol-2-yl)ethylsulfanyl]ethyl]-1H-benzimidazole (tebb) of formula [Ni(tebb)2](ClO4)2 has been prepared and its structure was proved by X-ray crystallography. The central nickel atom is in deformed octahedral vicinity. Four nitrogen atoms of two ligands form plane of octahedral and sulfur atoms are in apical positions. Perchlorate anions are outside the coordination sphere. The coordination compound was tested for its biological activities in an array of in vitro assays. It was found that the synthesized complex possesses interesting biological activity, which is most likely related to its cell-type related uptake kinetics. The synthesized complex is readily uptaken by malignant MDA-MB-231 and CACO-2 cells with the lowest uptake by healthy Hs27 fibroblasts. The lowest IC50 values were obtained for MDA-MB-231 cells (5.2-12.7 μM), highlighting exceptional differential cytotoxicity (IC50 values for healthy fibroblasts were 38.6-51.5 μM). Furthermore, it was found the complex is capable to cause hydrolytic DNA cleavage, promotes an efficient DNA fragmentation and to trigger an extensive formation of intracellular reactive oxygen species. Overall, current work presents a synthesis of Ni(II) coordination compound with interesting biological behavior and with a promising potential to be further tested in pre-clinical models.

• Klíčová slova
• Benzimidazole, Biocompatibility, Cytotoxicity, Nickel coordination compound, Reactive oxygen species, X-ray,
• MeSH
• antitumorózní látky chemie   farmakologie   MeSH
• apoptóza účinky léků   MeSH
• benzimidazoly chemie   farmakologie   MeSH
• DNA účinky léků   MeSH
• fragmentace DNA účinky léků   MeSH
• komplexní sloučeniny chemie   farmakologie   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• ligandy MeSH
• nádorové buněčné linie MeSH
• nikl chemie   MeSH
• oxidační stres účinky léků   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• štěpení DNA účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• benzimidazoly MeSH
• DNA MeSH
• komplexní sloučeniny MeSH
• ligandy MeSH
• nikl MeSH
• reaktivní formy kyslíku MeSH

Two silver(I) aminoacidate complexes {[Ag4(L-HAla)4(NO3)3]NO3}n (AgAla, complex 1, Ala = alanine) and {[Ag(L-Phe)]}n (AgPhe, complex 2, Phe = phenylalanine) were prepared and characterized by elemental, spectral analysis (FT-IR, NMR techniques) and single crystal X-ray analysis in solid state and their solution stability was measured in biological testing time-scale by 1H NMR. The bridging coordination modes of the zwitterionic Ala and deprotonated Phe ligands led to the formation of 1D polymeric chains of the complexes. The significant argentophilic interactions are presented in the structure of AgAla. Antimicrobial testing of prepared Ag(I) complexes was evaluated by IC50 and MIC values and were compared with AgGly, silver(I) sulfadiazine and AgNO3 samples. Moreover, MTS test was used to the testing of broad range antiproliferative activity of studied compounds against different cancer cell lines and also to the investigation of calf thymus DNA interactions by absorption spectroscopy, fluorescence spectroscopy, Ethidium bromide/Hoechst 33258 displacement experiments and circular dichroism spectroscopy. To evaluate the pUC19 DNA fragmentation by silver(I) complexes, the agarose gel electrophoresis was used. In addition to biological evaluation we used lipophilicity measurement results in the discussion about structure-activity relationship (SAR).

• Klíčová slova
• Anticancer activity, Antimicrobial activity, Groove binding, Nuclease activity, Silver(I) complexes, Stability in solution,
• MeSH
• alanin chemie   metabolismus   farmakologie   MeSH
• antibakteriální látky chemie   metabolismus   farmakologie   MeSH
• antifungální látky chemie   metabolismus   farmakologie   MeSH
• antitumorózní látky chemie   metabolismus   farmakologie   MeSH
• Candida parapsilosis účinky léků   MeSH
• DNA metabolismus   MeSH
• Escherichia coli účinky léků   MeSH
• fenylalanin chemie   metabolismus   farmakologie   MeSH
• katalýza MeSH
• komplexní sloučeniny chemie   metabolismus   farmakologie   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• proliferace buněk účinky léků   MeSH
• skot MeSH
• Staphylococcus aureus účinky léků   MeSH
• štěpení DNA účinky léků   MeSH
• stříbro chemie   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alanin MeSH
• antibakteriální látky MeSH
• antifungální látky MeSH
• antitumorózní látky MeSH
• calf thymus DNA MeSH Prohlížeč
• DNA MeSH
• fenylalanin MeSH
• komplexní sloučeniny MeSH
• stříbro MeSH

A systematic study of several new types of hybrids of Cu-chelated clamped phenanthroline artificial metallonuclease (AMN) with triplex-forming oligonucleotides (TFO) for sequence-specific cleavage of double-stranded DNA (dsDNA) is reported. The synthesis of these AMN-TFO hybrids is based on application of the alkyne-azide cycloaddition click reaction as the key step. The AMN was attached through different linkers at either the 5'- or 3'-ends or in the middle of the TFO stretch. The diverse hybrids efficiently formed triplexes with the target purine-rich sequence and their copper complexes were studied for their ability to cleave dsDNA in the presence of ascorbate as a reductant. In all cases, the influence of the nature and length of the AMN-TFO, time, conditions and amounts of ascorbate were studied, and optimum conjugates and a procedure that gave reasonably efficient (up to 34 %) cleavage of the target sequence, while rendering an off-target dsDNA intact, were found. The footprint of cleavage on PAGE was identified only in one case, with low conversion; this means that cleavage does not proceed with single nucleotide precision. On the other hand, these AMN-TFO hybrids are useful for the selective degradation of target dsDNA sequences. Future improvements to this design may provide higher resolution and selectivity.

• Klíčová slova
• DNA cleavage, click chemistry, copper, nucleases, oligonucleotides,
• MeSH
• deoxyribonukleasy chemie   metabolismus   MeSH
• DNA chemie   metabolismus   MeSH
• fenantroliny chemická syntéza   chemie   MeSH
• konformace nukleové kyseliny MeSH
• oligonukleotidy chemie   MeSH
• sekvence nukleotidů MeSH
• štěpení DNA * MeSH
• syntetická chemie okamžité shody MeSH
• tranzitní teplota MeSH
• ultrafialové záření MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• deoxyribonukleasy MeSH
• DNA MeSH
• fenantroliny MeSH
• oligonukleotidy MeSH
• triplex DNA MeSH Prohlížeč

The adverse side effects and acquired resistance associated with the clinical application of traditional platinum-based anticancer drugs have forced investigation of alternative transition metal-based compounds and their cytostatic properties. Over the last years, the anticancer potential of cobalt complexes has been extensively studied, and in-depth analyses of their mode of action have been conducted. In this work, we present antiproliferative activity against human cancer cells of the dinuclear Co(III) complexes bearing the quinizarin ligand and tris(2-aminoethyl)amine (tren, compound 1) or tris(2-pyridylmethyl)amine (tpa, compound 2) co-ligands. To contribute the understanding mechanisms of biological action of these compounds, their association with DNA in the cells, DNA binding in cell-free media, and DNA cleavage capability were investigated in detail. The results demonstrate that both complexes interact with DNA in tumor cells. However, their mechanism of antiproliferative action is different, and this difference is mirrored by distinct antiproliferative activity. The antiproliferative effect of 1 is connected with its ability to intercalate into DNA and subsequently to inhibit activities of DNA processing enzymes. In contrast, the total antiproliferative efficiency of 2, thanks to its redox properties, appears to be connected with its ability to form radicals and, consequently, with the ability of 2 to cleave DNA. Hence, the findings presented in this study may significantly contribute to understanding the antitumor potential of cobalt complexes. Dinuclear Co(III) complexes containing the bioactive quinizarin ligand exhibit antiproliferative activity based on distinct mechanism.

• Klíčová slova
• Antiproliferative activity, Cobalt, DNA, Quinizarin, Radicals,
• MeSH
• anthrachinony chemie   farmakologie   MeSH
• antitumorózní látky chemická syntéza   chemie   farmakologie   MeSH
• DNA chemie   MeSH
• kobalt chemie   farmakologie   MeSH
• komplexní sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• ligandy MeSH
• molekulární konformace MeSH
• nádorové buňky kultivované MeSH
• proliferace buněk účinky léků   MeSH
• štěpení DNA MeSH
• vazebná místa účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1,4-dihydroxyanthraquinone MeSH Prohlížeč
• anthrachinony MeSH
• antitumorózní látky MeSH
• calf thymus DNA MeSH Prohlížeč
• DNA MeSH
• kobalt MeSH
• komplexní sloučeniny MeSH
• ligandy MeSH

Two water-soluble mono-nuclear macrocyclic lanthanum(III) complexes of 2,6-diformyl-4-methylphenol with 1,3-diamino-2-propanol (C1) or 1,3-propylenediamine (C2) were synthesized and characterized by UV-Vis, FT-IR, 13C and 1H NMR spectroscopy and elemental analysis. C1 complex was structurally characterized by single-crystal X-ray diffraction, which revealed that the complex was mononuclear and ten-coordinated. The coordination sites around lanthanum(III) were occupied with a five-dentate ligand, two bidentate nitrates, and one water molecule. The interaction of complexes with DNA was studied in buffered aqueous solution at pH7.4. UV-Vis absorption spectroscopy, emission spectroscopy, circular dichroism (CD) and viscometric measurements provided clear evidence of the intercalation mechanism of binding. The obtained intrinsic binding constants (Kb) 9.3×103 and 1.2×103M-1 for C1 and C2, respectively confirmed that C1 is better intercalator than C2. The DNA docking studies suggested that the complexes bind with DNA in a groove binding mode with the binding affinity of C1>C2. Moreover, agarose gel electrophoresis study of the DNA-complex for both compounds revealed that the C1 intercalation cause ethidium bromide replacement in a competitive manner which confirms the suggested mechanism of binding. Finally, the anticancer experiments for the treated cancerous cell lines with both synthesized compounds show that these hydrophilic molecules need a suitable carrier to pass through the hydrophobic nature of cell membrane efficiently.

• Klíčová slova
• Binding constant, Chitosan, Cytotoxicity, DNA cleavage, Lanthanum(III), Molecular docking,
• MeSH
• buněčná smrt účinky léků   MeSH
• chitosan chemie   MeSH
• cirkulární dichroismus MeSH
• DNA metabolismus   MeSH
• elektrony MeSH
• fluorescenční spektrometrie MeSH
• jodidy chemie   MeSH
• kinetika MeSH
• komplexní sloučeniny chemie   farmakologie   MeSH
• krystalografie rentgenová MeSH
• lanthan chemie   MeSH
• lidé MeSH
• magnetické nanočástice chemie   MeSH
• molekulární konformace MeSH
• nádorové buněčné linie MeSH
• osmolární koncentrace MeSH
• simulace molekulového dockingu MeSH
• štěpení DNA * MeSH
• systémy cílené aplikace léků * MeSH
• viabilita buněk účinky léků   MeSH
• viskozita MeSH
• voda chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chitosan MeSH
• DNA MeSH
• jodidy MeSH
• komplexní sloučeniny MeSH
• lanthan MeSH
• magnetické nanočástice MeSH
• voda MeSH

The limitations associated with the clinical utility of conventional platinum anticancer drugs have stimulated research leading to the design of new metallodrugs with improved pharmacological properties, particularly with increased selectivity for cancer cells. Very recent research has demonstrated that photoactivation or photopotentiation of platinum drugs can be one of the promising approaches to tackle this challenge. This is so because the application of irradiation can be targeted exclusively to the tumor tissue so that the resulting effects could be much more selective and targeted to the tumor. We show in this work that the presence of 1-methyl-7-azaindole in trans-[PtCl2(NH3)(L)] (L = 1-methyl-7-azaindole, compound 1) markedly potentiated the DNA binding ability of 1 when irradiated by UVA light in a cell-free medium. Concomitantly, the formation of cytotoxic bifunctional cross-links was markedly enhanced. In addition, 1, when irradiated with UVA, was able to effectively cleave the DNA backbone also in living cells. The incorporation of 1-methyl-7-azaindole moiety had also a profound effect on the photophysical properties of 1, which can generate singlet oxygen responsible for the DNA cleavage reaction. Finally, we found that 1, upon irradiation with UVA light, exhibited a pronounced dose-dependent decrease in viability of A2780 cells whereas it was markedly less cytotoxic if the cells were treated in the absence of light. Hence, it is possible to conclude that 1 is amenable to photodynamic therapy.

• MeSH
• antitumorózní látky * chemie   farmakologie   účinky záření   MeSH
• cisplatina * chemie   farmakologie   účinky záření   MeSH
• DNA účinky léků   metabolismus   MeSH
• fragmentace DNA MeSH
• indoly * chemie   farmakologie   účinky záření   MeSH
• lidé MeSH
• ligandy MeSH
• nádorové buněčné linie MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• singletový kyslík chemie   MeSH
• štěpení DNA MeSH
• ultrafialové záření MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antitumorózní látky * MeSH
• cisplatina * MeSH
• DNA MeSH
• indoly * MeSH
• ligandy MeSH
• reaktivní formy kyslíku MeSH
• singletový kyslík MeSH
• transplatin MeSH Prohlížeč

We report DNA cleavage by ruthenium(II) arene anticancer complex [(η(6)-p-terp)Ru(II)(en)Cl](+) (p-terp=para-terphenyl, en=1,2-diaminoethane, complex 1) after its photoactivation by UVA and visible light, and the toxic effects of photoactivated 1 in cancer cells. It was shown in our previous work (T. Bugarcic et al., J. Med. Chem. 51 (2008) 5310-5319) that this complex exhibits promising toxic effects in several human tumor cell lines and concomitantly its DNA binding mode involves combined intercalative and monofunctional (coordination) binding modes. We demonstrate in the present work that when photoactivated by UVA or visible light, 1 efficiently photocleaves DNA, also in hypoxic media. Studies of the mechanism underlying DNA cleavage by photoactivated 1 reveal that the photocleavage reaction does not involve generation of reactive oxygen species (ROS), although contribution of singlet oxygen ((1)O2) to the DNA photocleavage process cannot be entirely excluded. Notably, the mechanism of DNA photocleavage by 1 appears to involve a direct modification of mainly those guanine residues to which 1 is coordinatively bound. As some tumors are oxygen-deficient and cytotoxic effects of photoactivated ruthenium compounds containing {Ru(η(6)-arene)}(2+) do not require the presence of oxygen, this class of ruthenium complexes may be considered potential candidate agents for improved photodynamic anticancer chemotherapy.

• Klíčová slova
• Antitumor activity, Comet assay, DNA cleavage, Photodynamic chemotherapy, Phototoxicity, Ruthenium anticancer complex,
• MeSH
• antitumorózní látky chemická syntéza   farmakologie   MeSH
• DNA chemie   MeSH
• ethylendiaminy chemie   MeSH
• fotochemoterapie MeSH
• kationty dvojmocné MeSH
• komplexní sloučeniny chemická syntéza   farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• organokovové sloučeniny chemická syntéza   farmakologie   MeSH
• plazmidy chemie   MeSH
• ruthenium chemie   MeSH
• sekvence nukleotidů MeSH
• singletový kyslík chemie   MeSH
• štěpení DNA účinky léků   účinky záření   MeSH
• světlo MeSH
• terfenylové sloučeniny chemie   MeSH
• viabilita buněk účinky léků   účinky záření   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• DNA MeSH
• ethylendiaminy MeSH
• ethylenediamine MeSH Prohlížeč
• kationty dvojmocné MeSH
• komplexní sloučeniny MeSH
• organokovové sloučeniny MeSH
• ruthenium MeSH
• singletový kyslík MeSH
• terfenylové sloučeniny MeSH

The conjugation of redox-active complexes that can function as chemical nucleases to cationic tetrapeptides is pursued in this work in order to explore the expected synergistic effect between these two elements in DNA oxidative cleavage. Coordination complexes of biologically relevant first row metal ions, such as Zn(II) or Cu(II), containing the tetradentate ligands 1,4-dimethyl-7-(2-pyridylmethyl)-1,4,7-triazacyclononane ((Me2)PyTACN) and (2S,2S')-1,1'-bis(pyrid-2-ylmethyl)-2,2'-bipyrrolidine ((S,S')-BPBP) have been linked to a cationic LKKL tetrapeptide sequence. Solid-phase synthesis of the peptide-tetradentate ligand conjugates has been developed, and the preparation and characterization of the corresponding metallotetrapeptides is described. The DNA cleavage activity of Cu and Zn metallopeptides has been evaluated and compared to their metal binding conjugates as well as to the parent complexes and ligands. Very interestingly, the oxidative Cu metallopeptides 1Cu and 2Cu show an enhanced activity compared to the parent complexes, [Cu(PyTACN)](2+) and [Cu(BPBP)](2+), respectively. Under optimized conditions, 1Cu displays an apparent pseudo first-order rate constant (kobs) of ∼0.16 min(-1) with a supercoiled DNA half-life time (t1/2) of ∼4.3 min. On the other hand, kobs for 2Cu has been found to be ∼0.11 min(-1) with t1/2 ≈ 6.4 min. Hence, these results point out that the DNA cleavage activities promoted by the metallopeptides 1Cu and 2Cu render ∼4-fold and ∼23 rate accelerations in comparison with their parent Cu complexes. Additional binding assays and mechanistic studies demonstrate that the enhanced cleavage activities are explained by the presence of the cationic LKKL tetrapeptide sequence, which induces an improved binding affinity to the DNA, thus bringing the metal ion, which is responsible for cleavage, in close proximity.

• MeSH
• aza sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• kinetika MeSH
• komplexní sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• lidé MeSH
• ligandy MeSH
• měď MeSH
• MFC-7 buňky MeSH
• oligopeptidy chemická syntéza   chemie   farmakologie   MeSH
• plazmidy MeSH
• pyridiny chemická syntéza   chemie   farmakologie   MeSH
• štěpení DNA účinky léků   MeSH
• superhelikální DNA chemie   metabolismus   MeSH
• zinek MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-(2-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane MeSH Prohlížeč
• aza sloučeniny MeSH
• komplexní sloučeniny MeSH
• ligandy MeSH
• měď MeSH
• oligopeptidy MeSH
• pyridiny MeSH
• superhelikální DNA MeSH
• zinek MeSH

A systematic study of the cleavage of DNA sequences containing 5-fluorocytosine or 5-fluorouracil by type II restriction endonucleases (REs) was performed and the results compared with the same sequences containing natural pyrimidine bases, uracil or 5-methylcytosine. The results show that some REs recognize fluorine as a hydrogen on cytosine and cleave the corresponding sequences where the presence of m5dC leads to blocking of the cleavage. However, on uracil, the same REs recognize the F as a methyl surrogate and cleave the sequences which are not cleaved if uracil is incorporated instead of thymine. These results are interesting for understanding the recognition of DNA sequences by REs and for manipulation of the specific DNA cutting.

• Klíčová slova
• DNA, DNA polymerase, Modified nucleotides, Pyrimidine nucleosides, Restriction endonucleases,
• MeSH
• DNA analýza   metabolismus   MeSH
• flucytosin chemie   MeSH
• fluorouracil chemie   MeSH
• restrikční endonukleasy typu II metabolismus   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• štěpení DNA MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA MeSH
• flucytosin MeSH
• fluorouracil MeSH
• restrikční endonukleasy typu II MeSH

Type I restriction-modification enzymes are multifunctional heteromeric complexes with DNA cleavage and ATP-dependent DNA translocation activities located on motor subunit HsdR. Functional coupling of DNA cleavage and translocation is a hallmark of the Type I restriction systems that is consistent with their proposed role in horizontal gene transfer. DNA cleavage occurs at nonspecific sites distant from the cognate recognition sequence, apparently triggered by stalled translocation. The X-ray crystal structure of the complete HsdR subunit from E. coli plasmid R124 suggested that the triggering mechanism involves interdomain contacts mediated by ATP. In the present work, in vivo and in vitro activity assays and crystal structures of three mutants of EcoR124I HsdR designed to probe this mechanism are reported. The results indicate that interdomain engagement via ATP is indeed responsible for signal transmission between the endonuclease and helicase domains of the motor subunit. A previously identified sequence motif that is shared by the RecB nucleases and some Type I endonucleases is implicated in signaling.

• MeSH
• adenosintrifosfát chemie   metabolismus   MeSH
• DNA bakterií MeSH
• Escherichia coli genetika   metabolismus   MeSH
• exodeoxyribonukleasa V chemie   genetika   metabolismus   MeSH
• exprese genu MeSH
• konformace nukleové kyseliny MeSH
• krystalografie rentgenová MeSH
• molekulární modely MeSH
• mutace MeSH
• plazmidy chemie   metabolismus   MeSH
• podjednotky proteinů chemie   genetika   metabolismus   MeSH
• proteiny - lokalizační signály MeSH
• proteiny z Escherichia coli chemie   genetika   metabolismus   MeSH
• restrikční endonukleasy typu I chemie   genetika   metabolismus   MeSH
• signální transdukce MeSH
• štěpení DNA MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfát MeSH
• DNA bakterií MeSH
• exodeoxyribonuclease V, E coli MeSH Prohlížeč
• exodeoxyribonukleasa V MeSH
• HsdR protein, E coli MeSH Prohlížeč
• podjednotky proteinů MeSH
• proteiny - lokalizační signály MeSH
• proteiny z Escherichia coli MeSH
• restrikční endonukleasy typu I MeSH