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1.
Int J Nanomedicine ; 15: 2583-2603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368042

RESUMO

Introduction: Over the past several years, nano-based therapeutics were an effective cancer drug candidate in order to overcome the persistence of deadliest diseases and prevalence of multiple drug resistance (MDR). Methods: The main objective of our program was to design organosilane-modified Fe3O4/SiO2/APTS(~NH2) core magnetic nanocomposites with functionalized copper-Schiff base complex through the use of (3-aminopropyl)triethoxysilane linker as chemotherapeutics to cancer cells. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), TEM, and vibrating sample magnetometer (VSM) techniques. All analyses corroborated the successful synthesis of the nanoparticles. In the second step, all compounds of magnetic nanoparticles were validated as antitumor drugs through the conventional MTT assay against K562 (myelogenous leukemia cancer) and apoptosis study by Annexin V/PI and AO/EB. The molecular dynamic simulations of nanoparticles were further carried out; afterwards, the optimization was performed using MM+, semi-empirical (AM1) and Ab Initio (STO-3G), ForciteGemo Opt, Forcite Dynamics, Forcite Energy and CASTEP in Materials studio 2017. Results: The results showed that the anti-cancer activity was barely reduced after modifying the surface of the Fe3O4/SiO2/APTS nanoparticles with 2-hydroxy-3-methoxybenzaldehyde as Schiff base and then Cu(II) complex. The apoptosis study by Annexin V/PI and AO/EB stained cell nuclei was performed that apoptosis percentage of the nanoparticles increased upon increasing the thickness of Fe3O4 shell on the magnetite core. The docking studies of the synthesized compounds were conducted towards the DNA and Topoisomerase II via AutoDock 1.5.6 (The Scripps Research Institute, La Jolla, CA, USA). Conclusion: Results of biology activities and computational modeling demonstrate that nanoparticles were targeted drug delivery system in cancer treatment.


Assuntos
Cobre/química , Compostos Férricos/síntese química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Propilaminas/síntese química , Bases de Schiff/síntese química , Silanos/síntese química , Dióxido de Silício/síntese química , Apoptose , Núcleo Celular/metabolismo , DNA/química , DNA Topoisomerases Tipo II/química , Compostos Férricos/química , Humanos , Células K562 , Magnetismo , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/ultraestrutura , Propilaminas/química , Bases de Schiff/química , Silanos/química , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
2.
Cell Mol Life Sci ; 77(1): 81-91, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31728578

RESUMO

The compaction of DNA and the continuous action of DNA transactions, including transcription and DNA replication, create complex DNA topologies that require Type IIA Topoisomerases, which resolve DNA topological strain and control genome dynamics. The human TOP2 enzymes catalyze their reactions via formation of a reversible covalent enzyme DNA-protein crosslink, the TOP2 cleavage complex (TOP2cc). Spurious interactions of TOP2 with DNA damage, environmental toxicants and chemotherapeutic "poisons" perturbs the TOP2 reaction cycle, leading to an accumulation of DNA-protein crosslinks, and ultimately, genomic instability and cell death. Emerging evidence shows that TOP2-DNA protein crosslink (DPC) repair entails multiple strand break repair activities, such as removal of the poisoned TOP2 protein and rejoining of the DNA ends through homologous recombination (HR) or non-homologous end joining (NHEJ). Herein, we discuss the molecular mechanisms of TOP2-DPC resolution, with specific emphasis on the recently uncovered ZATTZnf451-licensed TDP2-catalyzed TOP2-DPC reversal mechanism.


Assuntos
Quebras de DNA , Reparo do DNA , DNA Topoisomerases Tipo II/metabolismo , DNA/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Aminoaciltransferases/química , Aminoaciltransferases/metabolismo , Animais , DNA/química , DNA/genética , DNA Topoisomerases Tipo II/química , Humanos , Proteínas de Ligação a Poli-ADP-Ribose/química , Conformação Proteica , Sumoilação , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
3.
J Cell Biol ; 219(1)2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31712254

RESUMO

Topoisomerase II (Topo II) is essential for mitosis since it resolves sister chromatid catenations. Topo II dysfunction promotes aneuploidy and drives cancer. To protect from aneuploidy, cells possess mechanisms to delay anaphase onset when Topo II is perturbed, providing additional time for decatenation. Molecular insight into this checkpoint is lacking. Here we present evidence that catalytic inhibition of Topo II, which activates the checkpoint, leads to SUMOylation of the Topo II C-terminal domain (CTD). This modification triggers mobilization of Aurora B kinase from inner centromeres to kinetochore proximal centromeres and the core of chromosome arms. Aurora B recruitment accompanies histone H3 threonine-3 phosphorylation and requires Haspin kinase. Strikingly, activation of the checkpoint depends both on Haspin and Aurora B. Moreover, mutation of the conserved CTD SUMOylation sites perturbs Aurora B recruitment and checkpoint activation. The data indicate that SUMOylated Topo II recruits Aurora B to ectopic sites, constituting the molecular trigger of the metaphase checkpoint when Topo II is catalytically inhibited.


Assuntos
Aurora Quinase B/metabolismo , Cromossomos Humanos/genética , DNA Topoisomerases Tipo II/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metáfase , Mitose , Proteínas Serina-Treonina Quinases/metabolismo , Sumoilação , Aurora Quinase B/genética , Segregação de Cromossomos , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Cinetocoros , Fosforilação , Piperazinas/farmacologia , Proteínas Serina-Treonina Quinases/genética , Inibidores da Topoisomerase II/farmacologia
4.
Int J Mol Sci ; 20(24)2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31817267

RESUMO

Ovarian cancer is the most lethal gynecological malignancy, often because of the frequent insurgence of chemoresistance to the drugs currently used. Thus, new therapeutical agents are needed. We tested the toxicity of 16 new DNA-intercalating agents to cisplatin (cDDP)-sensitive human ovarian carcinoma cell lines and their resistant counterparts. The compounds were the complexes of Pt(II) or Pd(II) with bipyridyl (bipy) and phenanthrolyl (phen) and with four different thiourea ancillary ligands. Within each of the four series of complexes characterized by the same thiourea ligand, the Pd(phen) drugs invariably showed the highest anti-proliferative efficacy. This paralleled both a higher intracellular drug accumulation and a more efficient DNA intercalation than all the other metal-bidentate ligand combinations. The consequent inhibition of topoisomerase II activity led to the greatest inhibition of DNA metabolism, evidenced by the inhibition of the expression of the folate cycle enzymes and a marked perturbation of cell-cycle distribution in both cell lines. These findings indicate that the particular interaction of Pd(II) with phenanthroline confers the best pharmacokinetic and pharmacodynamic properties that make this class of DNA intercalators remarkable inhibitors, even of the resistant cell growth.


Assuntos
Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Substâncias Intercalantes/farmacologia , Fenantrolinas/química , Tioureia/química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Complexos de Coordenação/metabolismo , Complexos de Coordenação/farmacologia , DNA/química , DNA/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Feminino , Humanos , Substâncias Intercalantes/química , Ligantes , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Paládio/química , Platina/química
5.
Chem Commun (Camb) ; 55(85): 12857-12860, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31598611

RESUMO

5-Hydroxy-2-phenyl-7-(thiiran-2-ylmethoxy)-4H-chromen-4-one (compound 52) was found as a DNA non-intercalative topo II specific catalytic inhibitor by targeting its ATP-binding domain. Showing changes in interaction with Mg2+, it exhibited highly selective properties against the α-isoform with less toxicity, unlike other topo II poisons, such as etoposide.


Assuntos
Trifosfato de Adenosina/química , DNA Topoisomerases Tipo II/química , Proteínas de Ligação a DNA/química , Inibidores da Topoisomerase II/química , Trifosfato de Adenosina/metabolismo , Biocatálise , DNA/química , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Etoposídeo/química , Humanos , Domínios Proteicos , Isoformas de Proteínas , Inibidores da Topoisomerase II/metabolismo
6.
Int J Biol Macromol ; 138: 582-589, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323270

RESUMO

In the present study, acridine-thiosemicarbazones (ATD) derivatives were tested for their interaction properties with BSA through UV-Vis absorption and fluorescence spectroscopic studies. Both hyperchromic and hypochromic effects, as well as red or blue shifts were demonstrated after the derivatives were added to the BSA. Values for the binding constant (Kb) ranged from 1.62 × 104 to 8.71 × 105 M-1 and quenching constant (KSV) from 3.46 × 102 to 7.83 × 103 M-1 indicating a good affinity to BSA protein. Complementary, two compounds were selected to assess their inhibition activity against topoisomerase IIα enzyme, of which derivative 3a presented the best result. Moreover, to evaluate protein-ligand interactions, as well as the antitopoisomerase potential of these compounds, tests of molecular modeling were performed between all compounds using the albumin and Topoisomerase IIα/DNA complex. Finally, in silico studies showed that all derivatives used in this research displayed good oral bioavailability potential.


Assuntos
Acridinas/química , Soroalbumina Bovina/química , Tiossemicarbazonas/química , Inibidores da Topoisomerase/química , Inibidores da Topoisomerase/farmacologia , Técnicas de Química Sintética , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Soroalbumina Bovina/metabolismo , Análise Espectral , Relação Estrutura-Atividade , Inibidores da Topoisomerase/síntese química , Inibidores da Topoisomerase/metabolismo
7.
Nucleic Acids Res ; 47(15): 8163-8179, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31287876

RESUMO

Type II topoisomerases catalyze essential DNA transactions and are proven drug targets. Drug discrimination by prokaryotic and eukaryotic topoisomerases is vital to therapeutic utility, but is poorly understood. We developed a next-generation sequencing (NGS) approach to identify drug-resistance mutations in eukaryotic topoisomerases. We show that alterations conferring resistance to poisons of human and yeast topoisomerase II derive from a rich mutational 'landscape' of amino acid substitutions broadly distributed throughout the entire enzyme. Both general and discriminatory drug-resistant behaviors are found to arise from different point mutations found at the same amino acid position and to occur far outside known drug-binding sites. Studies of selected resistant enzymes confirm the NGS data and further show that the anti-cancer quinolone vosaroxin acts solely as an intercalating poison, and that the antibacterial ciprofloxacin can poison yeast topoisomerase II. The innate drug-sensitivity of the DNA binding and cleavage region of human and yeast topoisomerases (particularly hTOP2ß) is additionally revealed to be significantly regulated by the enzymes' adenosine triphosphatase regions. Collectively, these studies highlight the utility of using NGS-based methods to rapidly map drug resistance landscapes and reveal that the nucleotide turnover elements of type II topoisomerases impact drug specificity.


Assuntos
Ciprofloxacino/farmacologia , DNA Topoisomerases Tipo II/metabolismo , Naftiridinas/farmacologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Tiazóis/farmacologia , Inibidores da Topoisomerase II/farmacologia , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , DNA/química , DNA/genética , DNA/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Modelos Moleculares , Mutação , Conformação de Ácido Nucleico , Ligação Proteica , Domínios Proteicos , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/genética
8.
Mol Cell ; 75(2): 252-266.e8, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31202577

RESUMO

Topoisomerase II (TOP2) relieves torsional stress by forming transient cleavage complex intermediates (TOP2ccs) that contain TOP2-linked DNA breaks (DSBs). While TOP2ccs are normally reversible, they can be "trapped" by chemotherapeutic drugs such as etoposide and subsequently converted into irreversible TOP2-linked DSBs. Here, we have quantified etoposide-induced trapping of TOP2ccs, their conversion into irreversible TOP2-linked DSBs, and their processing during DNA repair genome-wide, as a function of time. We find that while TOP2 chromatin localization and trapping is independent of transcription, it requires pre-existing binding of cohesin to DNA. In contrast, the conversion of trapped TOP2ccs to irreversible DSBs during DNA repair is accelerated 2-fold at transcribed loci relative to non-transcribed loci. This conversion is dependent on proteasomal degradation and TDP2 phosphodiesterase activity. Quantitative modeling shows that only two features of pre-existing chromatin structure-namely, cohesin binding and transcriptional activity-can be used to predict the kinetics of TOP2-induced DSBs.


Assuntos
Quebras de DNA de Cadeia Dupla , DNA Topoisomerases Tipo II/química , DNA/genética , Complexos Multiproteicos/química , Proteínas de Ligação a Poli-ADP-Ribose/química , Quebra Cromossômica , Cromossomos/genética , DNA/química , Reparo do DNA/genética , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Etoposídeo/química , Conversão Gênica/genética , Células HCT116 , Humanos , Cinética , Complexos Multiproteicos/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia , Torção Mecânica , Transcrição Genética , Translocação Genética/genética
9.
Molecules ; 24(12)2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31197105

RESUMO

Molecular hybridization has proven to be a successful multi-target strategy in the design and development of new antitumor agents. Based on this rational approach, we have planned hybrid molecules containing covalently linked pharmacophoric units, present individually in compounds acting as inhibitors of the cancer protein targets tubulin, human topoisomerase II and ROCK1. Seven new molecules, selected by docking calculation of the complexes with each of the proteins taken into consideration, have been efficiently synthesized starting from 2,3-dichloro-1,4-naphtoquinone or 6,7-dichloro-5,8-quinolinquinone. By screening the full National Cancer Institute (NCI) panel, including 60 human cancer cell lines, four molecules displayed good and sometimes better growth inhibition GI50 than the ROCK inhibitor Y-27632, the Topo II inhibitor podophyllotoxin and the tubulin inhibitor combretastatin A-4. The relative position of N,N heteroatoms in the structures of the tested compounds was crucial in affecting bioactivity and selectivity. Furthermore, compound 3 (2-(4-(2-hydroxyethyl)piperazin-1-yl)-3-(3,4,5-trimethoxyphenoxy)naphthalene-1,4-dione) emerged as the most active in the series, showing a potent and selective inhibition of breast cancer BT-549 cells (GI50 < 10 nM).


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Inibidores da Topoisomerase II/farmacologia , Moduladores de Tubulina/farmacologia , Amidas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Naftoquinonas/síntese química , Naftoquinonas/química , Neoplasias/genética , Podofilotoxina/farmacologia , Piridinas/farmacologia , Quinolinas/síntese química , Quinolinas/química , Estilbenos/farmacologia , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/química , Tubulina (Proteína)/química , Tubulina (Proteína)/genética , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Quinases Associadas a rho/antagonistas & inibidores , Quinases Associadas a rho/química , Quinases Associadas a rho/genética
10.
Proc Natl Acad Sci U S A ; 116(17): 8149-8154, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30962387

RESUMO

Topological entanglements severely interfere with important biological processes. For this reason, genomes must be kept unknotted and unlinked during most of a cell cycle. Type II topoisomerase (TopoII) enzymes play an important role in this process but the precise mechanisms yielding systematic disentanglement of DNA in vivo are not clear. Here we report computational evidence that structural-maintenance-of-chromosomes (SMC) proteins-such as cohesins and condensins-can cooperate with TopoII to establish a synergistic mechanism to resolve topological entanglements. SMC-driven loop extrusion (or diffusion) induces the spatial localization of essential crossings, in turn catalyzing the simplification of knots and links by TopoII enzymes even in crowded and confined conditions. The mechanism we uncover is universal in that it does not qualitatively depend on the specific substrate, whether DNA or chromatin, or on SMC processivity; we thus argue that this synergy may be at work across organisms and throughout the cell cycle.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Genoma , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Ciclo Celular , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , DNA/genética , DNA/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo
11.
Bioorg Med Chem Lett ; 29(9): 1120-1126, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30846253

RESUMO

The novel hydroxyanthraquinone derivatives containing nitrogen-mustard and thiophene group were designed to covalently bind to topoisomerase II, and their structures were confirmed by nuclear magnetic resonance and high resolution mass spectrometer technologies in this article. The in vitro cytotoxicity against different cancer cell lines and one normal liver cell line (L02) was evaluated by MTT assay. Compound A1 was the most potent anti-proliferative agent against the human liver cancer HepG-2 cells (IC50 = 12.5 µM), and there is no obvious growth inhibitory effect on normal liver tissue L02 cells. The good cytotoxicity and selectivity of compound A1 suggest that it could be a promising lead for further optimization. The mechanisms of action about compound A1 and A4 were further investigated through analysis of cell apoptosis. Confocal microscopy tracks the location of compound A1 in the cell, which could enter the cytoplasm and nucleus, and induce severe deformation of the nucleus. The docking study demonstrated that A1 could interact with the catalytic active site in topoisomerase II.


Assuntos
Antraquinonas/química , Antineoplásicos/síntese química , Desenho de Fármacos , Antraquinonas/metabolismo , Antraquinonas/farmacologia , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Relação Estrutura-Atividade
12.
Phytomedicine ; 54: 109-119, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30668360

RESUMO

BACKGROUND: Phytochemical naphtho[1,2-b] furan-4,5­dione (NFD) presenting in Avicennia marina exert anti-cancer effects, but little is known regarding about DNA damage-mediated apoptosis in non-small-cell lung carcinoma (NSCLC). PURPOSE: To examine whether NFD-induced apoptosis of NSCLC cells is correlated with the induction of DNA damage, and to investigate its underlying mechanism. STUDY DESIGN: The anti-proliferative effects of NFD were assessed by MTS Assay Kit FACS assay, and in vivo nude mice xenograft assay. The DNA damage related proteins, the Bcl-2 family and pro-apoptotic factors were examined by immunofluorescence assay, q-PCR, and western blotting. The activity of NF-κB p65 in nuclear extracts was detected using a colorimetric DNA-binding ELISA assay. The inhibitory activity of topoisomerase II (TOPO II) was evaluated by molecular docking and TOPO II catalytic assay. RESULTS: NFD exerted selective cytotoxicity against NSCLC H1299, H1437 and A549 cells rather than normal lung-embryonated cells MRC-5. Remarkably, we found that NFD activated the hull marker and modulator of DNA damage repairs such as γ-H2AX, ATM, ATR, CHK1, and CHK2 probably caused by the accumulation of intracellular reactive oxygen species (ROS) and inhibition of TOPO II activity. Furthermore, the suppression of transcription factor NF-κB by NFD resulted in significantly decreased levels of pro-survival proteins including Bcl-2 family Bcl-2, Bcl-xL and Mcl-1 and the endogenous inhibitors of apoptosis XIAP and survivin in H1299 cells. Moreover, the nude mice xenograft assay further validated the suppression of H1299 growth by NFD, which is the first report for evaluating the anti-cancer effect of NFD in vivo. CONCLUSION: These findings provide a novel mechanism indicating the inhibition of TOPO II activity and NF-κB signaling by NFD, leading to DNA damage and apoptosis of NSCLC tumor cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Dano ao DNA/efeitos dos fármacos , DNA Topoisomerases Tipo II/metabolismo , Furanos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Naftoquinonas/farmacologia , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Animais , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/química , Feminino , Furanos/química , Humanos , Neoplasias Pulmonares/genética , Camundongos Nus , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Naftoquinonas/química , Proteínas de Ligação a Poli-ADP-Ribose/antagonistas & inibidores , Proteínas de Ligação a Poli-ADP-Ribose/química , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Molecules ; 24(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30621140

RESUMO

Engleromyces goetzei P. Henn. (E. goetzei) has been widely used as a traditional herb for many years in Kenya due to its diverse biological effects. Although engleromycin was first isolated from E. goetzei in 1980, its pharmacological activity is still unknown. In this study, engleromycin from E. goetzei was identified by spectroscopic analyses, and subsequently examined for its antiproliferative activity using human cancer cell lines of SGC-7901, HT-29, HeLa and A549. As a result, it was revealed that engleromycin strongly inhibited the growth of SGC-7901, HT-29, HeLa and A549 cells with IC50 values at 26.77 ± 1.69 µM, 7.73 ± 0.18 µM, 7.00 ± 0.12 µM and 3.14 ± 0.03 µM, respectively. The results of topoisomerase II (Top II) inhibition assay in vitro implied that engleromycin might be a Top II inhibitor. Further insights into the potential mechanism of antiproliferative activity displayed that engleromycin could dock into the binding pockets of Top II, like the clinical inhibitor doxorubicin, and then inhibit the biological activity of Top II. Taken together, our findings suggest that engleromycin has an anticancer potential, and may serve as a leading compound for the development of antitumor agents.


Assuntos
Proliferação de Células/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Inibidores da Topoisomerase II/farmacologia , Xylariales/química , Células A549 , Sítios de Ligação/efeitos dos fármacos , DNA Topoisomerases Tipo II/química , Células HeLa , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/química
14.
Bioorg Chem ; 83: 262-276, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30391699

RESUMO

AIM: Design and synthesis of novel nalidixic acid derivatives of potent anticancer and topoisomerase II inhibitory activities were our major aim. MATERIALS & METHODS: All the newly synthesized nalidixic acid derivatives were submitted to the National Cancer Institute (NCI), Bethesda, USA and were accepted for single dose screening. Further investigation via IC50 determination of the most potent compound 6a against K-562 and SR leukemia cell lines. Finally, the topoisomerase II inhibitory activity, the cell cycle analysis and molecular docking of 6a were performed in order to identify the possible mechanism of the anticancer activity. RESULTS: Compound 6a showed interesting selectivity against leukemia especially K-562 and SR subpanels with IC50 35.29 µM and 13.85 µM respectively. Moreover, compound 6a revealed potent topoisomerase IIα and topoisomerase IIß inhibitory activity compared with known topoisomerase inhibitors such as doxorubicin and topotecan with IC50 1.30 µM and 0.017 µM respectively. Cell cycle analysis indicated that compound 6a induced cell cycle arrest at G2-M phase leading to inhibition of cell proliferation and apoptosis. Molecular modeling demonstrated that the potent topoisomerase inhibitory activity of 6a was due to the interaction with the topoisomerase II enzyme through coordinate bonding with the magnesium ion Mg2+, hydrogen bonding with Asp 545 and arene cation interaction with His 759.


Assuntos
Antineoplásicos/farmacologia , Ácido Nalidíxico/análogos & derivados , Ácido Nalidíxico/farmacologia , Inibidores da Topoisomerase II/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Domínio Catalítico , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Relação Dose-Resposta a Droga , Desenho de Fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Ácido Nalidíxico/síntese química , Ácido Nalidíxico/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/química , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/metabolismo
15.
Nucleic Acids Res ; 47(1): 69-84, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30476194

RESUMO

The topological state of covalently closed, double-stranded DNA is defined by the knot type $K$ and the linking-number difference $\Delta Lk$ relative to unknotted relaxed DNA. DNA topoisomerases are essential enzymes that control the topology of DNA in all cells. In particular, type-II topoisomerases change both $K$ and $\Delta Lk$ by a duplex-strand-passage mechanism and have been shown to simplify the topology of DNA to levels below thermal equilibrium at the expense of ATP hydrolysis. It remains a key question how small enzymes are able to preferentially select strand passages that result in topology simplification in much larger DNA molecules. Using numerical simulations, we consider the non-equilibrium dynamics of transitions between topological states $(K,\Delta Lk)$ in DNA induced by type-II topoisomerases. For a biological process that delivers DNA molecules in a given topological state $(K,\Delta Lk)$ at a constant rate we fully characterize the pathways of topology simplification by type-II topoisomerases in terms of stationary probability distributions and probability currents on the network of topological states $(K,\Delta Lk)$. In particular, we observe that type-II topoisomerase activity is significantly enhanced in DNA molecules that maintain a supercoiled state with constant torsional tension. This is relevant for bacterial cells in which torsional tension is maintained by enzyme-dependent homeostatic mechanisms such as DNA-gyrase activity.


Assuntos
DNA Topoisomerases Tipo II/química , DNA Super-Helicoidal/química , DNA/química , Conformação de Ácido Nucleico , Trifosfato de Adenosina/química , Trifosfato de Adenosina/genética , Biologia Computacional/métodos , DNA/genética , DNA Girase/química , DNA Girase/genética , DNA Topoisomerases Tipo II/genética , DNA Super-Helicoidal/genética , Homeostase/genética , Hidrólise , Cinética , Transdução de Sinais/genética
16.
J Mol Graph Model ; 86: 1-18, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30296751

RESUMO

Merbarone is a derivative of thiobarbituric acid, possessing catalytic inhibitory potential against human topoisomerase IIα (hTopoIIα). Merbarone was reported to inhibit DNA cleavage by hTopoIIα. It is important to understand the molecular mechanism of hTopoIIα inhibition by merbarone, as these details guide the rational design of new ligands. In this work, a systematic pharmacoinformatics analysis has been reported to analyze the merbarone-hTopoIIα interactions and to identify merbarone analogs as potential hTopoIIα inhibitors. The reported crystal structure of hTopoIIα-DNA complex (PDB ID: 4FM9) is not suitable for analyzing the merbarone-binding domain, because it is a biological assembly of hTopoIIα in C-gate open conformation. Therefore, 3D structure of hTopoIIα-DNA complex suitable for molecular modeling analysis at merbarone binding site was first generated. Using this generated complex, molecular docking analysis and molecular dynamics simulations were performed to explore the effect of merbarone on hTopoIIα-DNA complex. The binding energy for the enol form of merbarone with hTopoIIα-DNA was estimated to be -51.28 kcal/mol. The explored binding site and identified molecular recognition interactions were in accordance with the previously reported interference in the DNA-cleavage by merbarone. Virtual screening was performed using drug likeness filters, toxicity filters and ADMET descriptor based filters followed by molecular docking (ZINC database). Sixteen compounds were identified as merbarone-functional analogs suitable for hTopoIIα inhibition. These identified molecules can be considered for further evaluation of their anti-hTopoIIα activity.


Assuntos
Sítios de Ligação , Biologia Computacional/métodos , DNA Topoisomerases Tipo II/química , Tiobarbitúricos/química , Inibidores da Topoisomerase II/química , DNA Topoisomerases Tipo II/farmacologia , Humanos , Ligação de Hidrogênio , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Ligação Proteica , Reprodutibilidade dos Testes , Relação Estrutura-Atividade , Tiobarbitúricos/farmacologia , Inibidores da Topoisomerase II/farmacologia
17.
Bioorg Chem ; 84: 347-354, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30530076

RESUMO

Human DNA topoisomerases (topos) have been recognized as a good target molecule for the development of anticancer drugs because they play an important role in solving DNA topological problems caused by DNA strand separation during replication and transcription. In this study, we designed and synthesized 11 novel chromone backbone compounds possessing epoxy and halohydrin substituents with chirality. In the topos inhibition test, compounds 2, 9, 10, and 11 showed comparable topo I inhibitory activity at concentration of 100 µM compared to camptothecin, and all of the synthesized compounds showed moderate topo IIα inhibitory activity. Among them, compounds 9, 10 and 11 were more potent than the others in both topo I and IIα inhibitory activity. Compound 11 showed the most potent cell antiproliferative activity against all tested cancer cell lines with particularly strong inhibition (an IC50 of 0.04 µM) of K562 myelogenous leukemia cancer cell proliferation. In the brief structure-activity relationship analysis, there was no clear correlation between stereochemistry and topos inhibitory and cytotoxic activity. 5(R),7(S)-bisepoxy-substituted compound 11 was the most potent DNA cross-linker and induced G2/M arrest in a cell cycle assay in a dose- and time-dependent manner. After the treatment time period induced apoptosis in K562 cells without increasing G2/M-phase cells. Overall, compound 11 showed good consistent inhibitory biological activity related to cancer cell proliferation.


Assuntos
Antineoplásicos/síntese química , Cromonas/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromonas/farmacologia , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/farmacologia
18.
Sci Rep ; 8(1): 14949, 2018 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-30297860

RESUMO

Topoisomerases II (Top2s) are a group of essential enzymes involved in replication, transcription, chromosome condensation, and segregation via altering DNA topology. The mechanism of the Top2s poisons such as etoposide (VP-16) was reported as stabilizing the Top2-DNA complex and engendering permanent DNA breakage. As the structurally similar compound of VP-16, a novel 4ß-sulfur-substituted 4'-demethylepipodophyllotoxin (DMEP) derivative (compound C-Bi) with superior antitumor activity was developed in our previous study. To understand the structural basis of the compound action, the crystal structure (2.54 Å) of human Top2 ß-isoform (hTop2ß) cleavage complexes stabilized by compound C-Bi was determined. However, compound C-Bi was not visible in the crystal structure. Through the comparison of the structures of hTop2ß-DNA-etoposide ternary complex and hTop2ß-DNA binary complex, it could be observed that the distance between drug-binding sites Arg503 of the two monomers was 26.62 Å in hTop2ß-DNA-etoposide ternary complex and 34.54 Å in hTop2ß-DNA binary complex, respectively. Significant twist were observed in the DNA chains of binary complex. It suggested that compound C-Bi played antitumor roles through increasing spacing of hTop2ß monomers. The changes in hTop2ß structure further caused double changes in the torsional direction and migration distance of the DNA chains, resulting in impeding religation of DNA.


Assuntos
Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , DNA Topoisomerases Tipo II/metabolismo , Podofilotoxina/análogos & derivados , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Inibidores da Topoisomerase II/farmacologia , Antineoplásicos/química , Benzimidazóis/química , DNA/química , DNA/metabolismo , DNA Topoisomerases Tipo II/química , Humanos , Modelos Moleculares , Podofilotoxina/química , Podofilotoxina/farmacologia , Proteínas de Ligação a Poli-ADP-Ribose/química , Conformação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Compostos de Enxofre/química , Compostos de Enxofre/farmacologia , Inibidores da Topoisomerase II/química
19.
Phys Rev Lett ; 121(14): 148001, 2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30339454

RESUMO

Biological systems are equipped with a diverse repertoire of proteins that regulate DNA topology with precision that is beyond the reach of conventional polymer chemistry. Here, we harness the unique properties of topoisomerases to synthesize Olympic hydrogels formed by topologically interlinked DNA rings. Using dynamic light scattering microrheology to probe the viscoelasticity of DNA topological networks, we show that topoisomerase II enables the facile preparation of active, adenosine triphosphate-driven Olympic hydrogels that can be switched between liquid and solid states on demand. Our results provide a versatile system for engineering switchable topological materials that may be broadly leveraged to model the impact of topological constraints and active dynamics in the physics of chromosomes and other polymeric materials.


Assuntos
DNA Topoisomerases Tipo II/química , DNA/química , Hidrogéis/síntese química , Proteínas de Ligação a Poli-ADP-Ribose/química , DNA/síntese química , Hidrogéis/química , Conformação Molecular , Plasmídeos/química
20.
Nucleic Acids Res ; 46(18): 9625-9636, 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30169847

RESUMO

Maintenance of topological homeostasis is vital for gene expression and genome replication in all organisms. Similar to other circular genomes, also mitochondrial DNA (mtDNA) is known to exist in various different topological forms, although their functional significance remains unknown. We report here that both known type II topoisomerases Top2α and Top2ß are present in mammalian mitochondria, with especially Top2ß regulating the supercoiling state of mtDNA. Loss of Top2ß or its inhibition by ciprofloxacin results in accumulation of positively supercoiled mtDNA, followed by cessation of mitochondrial transcription and replication initiation, causing depletion of mtDNA copy number. These mitochondrial effects block both cell proliferation and differentiation, possibly explaining some of the side effects associated with fluoroquinolone antibiotics. Our results show for the first time the importance of topology for maintenance of mtDNA homeostasis and provide novel insight into the mitochondrial effects of fluoroquinolones.


Assuntos
Ciprofloxacino/farmacologia , DNA Topoisomerases Tipo II/genética , DNA Mitocondrial/efeitos dos fármacos , Proteínas de Ligação a Poli-ADP-Ribose/genética , Linhagem Celular , Replicação do DNA/efeitos dos fármacos , DNA Topoisomerases Tipo II/química , DNA Mitocondrial/genética , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Proteínas de Ligação a Poli-ADP-Ribose/química , Transcrição Genética/efeitos dos fármacos
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