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1.
Molecules ; 26(7)2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33916405

RESUMO

The study aimed to investigate the antibacterial activity of Mustard (Brassica juncea) and Moringa (Moringa oleifera) leaf extracts and coagulant protein for their potential application in water treatment. Bacterial cell aggregation and growth kinetics studies were employed for thirteen bacterial strains with different concentrations of leaf extracts and coagulant protein. Moringa oleifera leaf extract (MOS) and coagulant protein showed cell aggregation against ten bacterial strains, whereas leaf extract alone showed growth inhibition of five bacterial strains for up to 6 h and five bacterial strains for up to 3 h. Brassica juncea leaf extract (BJS) showed growth inhibition for up to 6 h, and three bacterial strains showed inhibition for up to 3 h. The highest inhibition concentration with 2.5 mg/mL was 19 mm, and furthermore, the minimum inhibitory concentration (MIC) (0.5 mg/mL) and MBC (1.5 mg/mL) were determined to have a higher antibacterial effect for <3 KDa peptides. Based on LCMS analysis, napin was identified in both MOS and BJS; furthermore, the mode of action of napin peptide was determined on lipoprotein X complex (LpxC) and four-chained structured binding protein of bacterial type II topoisomerase (4PLB). The docking analysis has exhibited moderate to potent inhibition with a range of dock score -912.9 Kcal/mol. Thus, it possesses antibacterial-coagulant potential bioactive peptides present in the Moringa oleifera purified protein (MOP) and Brassica juncea purified protein (BJP) that could act as an effective antimicrobial agent to replace currently available antibiotics. The result implies that MOP and Brassica juncea purified coagulant (BJP) proteins may perform a wide degree of antibacterial functions against different pathogens.


Assuntos
Albuminas 2S de Plantas/química , Antibacterianos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Moringa oleifera/química , Mostardeira/química , Albuminas 2S de Plantas/isolamento & purificação , Albuminas 2S de Plantas/farmacologia , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/química , Amidoidrolases/genética , Amidoidrolases/metabolismo , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Sítios de Ligação , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/metabolismo , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/enzimologia , Bactérias Gram-Positivas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Folhas de Planta/química , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas
2.
Molecules ; 26(3)2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499325

RESUMO

Zygophyllum coccineum, an edible halophytic plant, is part of the traditional medicine chest in the Mediterranean region for symptomatic relief of diabetes, hypertension, wound healing, burns, infections, and rheumatoid arthritis pain. The current study aimed to characterize Z. coccineum phytoconstituents, and the evaluations of the anti-microbial-biofilm, and anti-cancers bioactivities of the plant's mother liquor, i.e., aqueous-ethanolic extract, and its subsequent fractions. The in silico receptors interaction feasibility of Z. coccineum major constituents with Staph GyraseB, and human topoisomerase-IIß (h-TOP-IIß) were conducted to confirm the plant's anti-microbial and anti-cancer biological activities. Thirty-eight secondary metabolites of flavonoids, stilbene, phenolic acids, alkaloids, and coumarin classes identified by LC-ESI-TOF-MS spectrometric analysis, and tiliroside (kaempferol-3-O-(6''''-p-coumaroyl)-glucoside, 19.8%), zygophyloside-F (12.78%), zygophyloside-G (9.67%), and isorhamnetin-3-O-glucoside (4.75%) were identified as the major constituents. A superior biofilm obliteration activity established the minimum biofilm eradication concentration (MBEC) for the chloroform fraction at 3.9-15.63 µg/mL, as compared to the positive controls (15.63-31.25 µg/mL) against all the microbial strains that produced the biofilm under study, except the Aspergillus fumigatus. The aqueous-ethanolic extract showed cytotoxic effects with IC50 values at 3.47, 3.19, and 2.27 µg/mL against MCF-7, HCT-116, and HepG2 cell-lines, respectively, together with the inhibition of h-TOP-IIß with IC50 value at 45.05 ng/mL in comparison to its standard referral inhibitor (staurosporine, IC50, 135.33 ng/mL). This conclusively established the anti-cancer activity of the aqueous-ethanolic extract that also validated by in silico receptor-binding predicted energy levels and receptor-site docking feasibility of the major constituents of the plant's extract. The study helped to authenticate some of the traditional phytomedicinal properties of the anti-infectious nature of the plant.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Zygophyllum/química , Biofilmes/efeitos dos fármacos , Simulação por Computador , DNA Girase/química , DNA Topoisomerases Tipo II/química , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Cromatografia Gasosa-Espectrometria de Massas , Células HCT116 , Células Hep G2 , Humanos , Técnicas In Vitro , Células MCF-7 , Medicina Tradicional , Região do Mediterrâneo , Simulação de Acoplamento Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Proteínas de Ligação a Poli-ADP-Ribose/antagonistas & inibidores , Proteínas de Ligação a Poli-ADP-Ribose/química , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia
3.
Int J Biol Macromol ; 170: 523-531, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33387542

RESUMO

Precise monitoring of the enzyme activity by a suitable modulator is one of the very fundamental aspects of drug designing that provides the opportunity to overcome the challenges of several diseases. Herein, inhibition of human Topoisomerase IIα enzyme which serves as a potential target site for several anti-cancer drugs is demonstrated by using ultra-small size gold nanoclusters (Au NCs) with the dimension comparable with size of the active site of the enzyme. Molecular dynamics simulation results demonstrate that the Au NCs strongly interact with the human Topo IIα enzyme at its active site or allosteric site depending on forms of enzyme. Additionally, binding energy and interaction profile provides the molecular basis of understanding of interactions of ultra-small size Au NCs and human Topo IIα enzyme. Enthalpy change (ΔH) and binding constant (K) are measured based on a sequential binding model of the Au NCs with the enzyme as demonstrated by the ITC study. Moreover, the in-vitro inhibition study of the catalytic activity of the enzyme and gel electrophoresis indicates that the ultra-small size Au NCs may be used as a potent inhibitor of human Topo IIα enzyme.


Assuntos
DNA Topoisomerases Tipo II/metabolismo , Corantes Fluorescentes/química , Ouro/química , Nanopartículas Metálicas/química , Sítio Alostérico/efeitos dos fármacos , Catálise/efeitos dos fármacos , Domínio Catalítico/efeitos dos fármacos , DNA Topoisomerases Tipo II/química , Humanos , Simulação de Dinâmica Molecular , Neoplasias/metabolismo
4.
PLoS Comput Biol ; 17(1): e1007814, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33465072

RESUMO

DNA topoisomerase II-ß (TOP2B) is fundamental to remove topological problems linked to DNA metabolism and 3D chromatin architecture, but its cut-and-reseal catalytic mechanism can accidentally cause DNA double-strand breaks (DSBs) that can seriously compromise genome integrity. Understanding the factors that determine the genome-wide distribution of TOP2B is therefore not only essential for a complete knowledge of genome dynamics and organization, but also for the implications of TOP2-induced DSBs in the origin of oncogenic translocations and other types of chromosomal rearrangements. Here, we conduct a machine-learning approach for the prediction of TOP2B binding using publicly available sequencing data. We achieve highly accurate predictions, with accessible chromatin and architectural factors being the most informative features. Strikingly, TOP2B is sufficiently explained by only three features: DNase I hypersensitivity, CTCF and cohesin binding, for which genome-wide data are widely available. Based on this, we develop a predictive model for TOP2B genome-wide binding that can be used across cell lines and species, and generate virtual probability tracks that accurately mirror experimental ChIP-seq data. Our results deepen our knowledge on how the accessibility and 3D organization of chromatin determine TOP2B function, and constitute a proof of principle regarding the in silico prediction of sequence-independent chromatin-binding factors.


Assuntos
Cromatina , DNA Topoisomerases Tipo II , Genoma/genética , Modelos Genéticos , Animais , Células Cultivadas , Cromatina/química , Cromatina/genética , Cromatina/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/metabolismo , Genômica , Humanos , Células MCF-7 , Aprendizado de Máquina , Camundongos , Ligação Proteica , Timócitos
5.
Mol Pharmacol ; 98(3): 222-233, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32587095

RESUMO

DNA topoisomerase II (TOP2) is required for the unwinding and decatenation of DNA through the induction of an enzyme-linked double-strand break (DSB) in one DNA molecule and passage of another intact DNA duplex through the break. Anticancer drugs targeting TOP2 (TOP2 poisons) prevent religation of the DSB and stabilize a normally transient intermediate of the TOP2 reaction mechanism called the TOP2-DNA covalent complex. Subsequently, TOP2 remains covalently bound to each end of the enzyme-bridged DSB, which cannot be repaired until TOP2 is removed from the DNA. One removal mechanism involves the proteasomal degradation of the TOP2 protein, leading to the liberation of a protein-free DSB. Proteasomal degradation is often regulated by protein ubiquitination, and here we show that inhibition of ubiquitin-activating enzymes reduces the processing of TOP2A- and TOP2B-DNA complexes. Depletion or inhibition of ubiquitin-activating enzymes indicated that ubiquitination was required for the liberation of etoposide-induced protein-free DSBs and is therefore an important layer of regulation in the repair of TOP2 poison-induced DNA damage. TOP2-DNA complexes stabilized by etoposide were shown to be conjugated to ubiquitin, and this was reduced by inhibition or depletion of ubiquitin-activating enzymes. SIGNIFICANCE STATEMENT: There is currently great clinical interest in the ubiquitin-proteasome system and ongoing development of specific inhibitors. The results in this paper show that the therapeutic cytotoxicity of DNA topoisomerase II (TOP2) poisons can be enhanced through combination therapy with ubiquitin-activating enzyme inhibitors or by specific inhibition of the BMI/RING1A ubiquitin ligase, which would lead to increased cellular accumulation or persistence of TOP2-DNA complexes.


Assuntos
DNA Topoisomerases Tipo II/metabolismo , Nucleosídeos/farmacologia , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Sulfonamidas/farmacologia , Enzimas Ativadoras de Ubiquitina/antagonistas & inibidores , Linhagem Celular , DNA/metabolismo , DNA Topoisomerases Tipo II/química , Humanos , Células K562 , Proteínas de Ligação a Poli-ADP-Ribose/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Ubiquitina/metabolismo , Ubiquitinação/efeitos dos fármacos
6.
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
7.
J Med Chem ; 63(7): 3508-3521, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32196342

RESUMO

We previously reported a first set of hybrid topoisomerase II (topoII) poisons whose chemical core merges key pharmacophoric elements of etoposide and merbarone, which are two well-known topoII blockers. Here, we report on the expansion of this hybrid molecular scaffold and present 16 more hybrid derivatives that have been designed, synthesized, and characterized for their ability to block topoII and for their overall drug-like profile. Some of these compounds act as topoII poison and exhibit good solubility, metabolic (microsomal) stability, and promising cytotoxicity in three cancer cell lines (DU145, HeLa, A549). Compound 3f (ARN24139) is the most promising drug-like candidate, with a good pharmacokinetics profile in vivo. Our results indicate that this hybrid new chemical class of topoII poisons deserves further exploration and that 3f is a favorable lead candidate as a topoII poison, meriting future studies to test its efficacy in in vivo tumor models.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Inibidores da Topoisomerase II/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , 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/metabolismo , Inibidores da Topoisomerase II/farmacocinética
8.
Int J Mol Sci ; 21(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32070048

RESUMO

In this work, three computational methods (Hatree-Fock (HF), Møller-Plesset 2 (MP2), and Density Functional Theory (DFT)) using a variety of basis sets are used to determine the atomic and molecular properties of dihydrothiouracil-based indenopyridopyrimidine (TUDHIPP) derivatives. Reactivity descriptors of this system, including chemical potential (µ), chemical hardness (η), electrophilicity (ω), condensed Fukui function and dual descriptors are calculated at B3LYP/6-311++ G (d,p) to identify reactivity changes of these molecules in both gas and aqueous phases. We determined the molecular electrostatic surface potential (MESP) to determine the most active site in these molecules. Molecular docking study of TUDHIPP with topoisomerase II α and ß is performed, predicting binding sites and binding energies with amino acids of both proteins. Docking studies of TUDHIPP versus etoposide suggest their potential as antitumor candidates. We have applied Lipinski, Veber's rules and analysis of the Golden triangle and structure activity/property relationship for a series of TUDHIPP derivatives indicate that the proposed compounds exhibit good oral bioavailability. The comparison of the drug likeness descriptors of TUDHIPP with those of etoposide, which is known to be an antitumor drug, indicates that TUDHIPP can be considered as an antitumor drug. The overall study indicates that TUDHIPP has comparable and even better descriptors than etoposide proposing that it can be as effective antitumor drug, especially 2H, 6H and 7H compounds.


Assuntos
DNA Topoisomerases Tipo II/química , Pirimidinas/química , Inibidores da Topoisomerase II/química , Uracila/química , Sítios de Ligação , Domínio Catalítico/efeitos dos fármacos , Teoria da Densidade Funcional , Humanos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Uracila/análogos & derivados
9.
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
10.
EMBO J ; 39(3): e101863, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31769059

RESUMO

Chromosome segregation in mitosis requires the removal of catenation between sister chromatids. Timely decatenation of sister DNAs at mitotic centromeres by topoisomerase IIα (TOP2A) is crucial to maintain genomic stability. The chromatin factors that recruit TOP2A to centromeres during mitosis remain unknown. Here, we show that histone H2A Thr-120 phosphorylation (H2ApT120), a modification generated by the mitotic kinase Bub1, is necessary and sufficient for the centromeric localization of TOP2A. Phosphorylation at residue-120 enhances histone H2A binding to TOP2A in vitro. The C-gate and the extreme C-terminal region are important for H2ApT120-dependent localization of TOP2A at centromeres. Preventing H2ApT120-mediated accumulation of TOP2A at mitotic centromeres interferes with sister chromatid disjunction, as evidenced by increased frequency of anaphase ultra-fine bridges (UFBs) that contain catenated DNA. Tethering TOP2A to centromeres bypasses the requirement for H2ApT120 in suppressing anaphase UFBs. These results demonstrate that H2ApT120 acts as a landmark that recruits TOP2A to mitotic centromeres to decatenate sister DNAs. Our study reveals a fundamental role for histone phosphorylation in resolving centromere DNA entanglements and safeguarding genomic stability during mitosis.


Assuntos
Centrômero/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , DNA/metabolismo , Histonas/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/química , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Sítios de Ligação , Linhagem Celular , Segregação de Cromossomos , Instabilidade Genômica , Células HeLa , Humanos , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Treonina
11.
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
12.
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
13.
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
14.
Bioorg Chem ; 93: 103289, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31586716

RESUMO

A novel series of halogenated ß-enaminonitriles (4a-m), linked 9-bromo-1H-benzo[f]-hromene moieties, were synthesized via microwave irradiation and were predestined for their cytotoxic activity versus three cancer cell lines, namely: MCF-7, HCT-116, and HepG-2. Several of the tested compounds showed high growth inhibitory activities versus the tumor cell lines. Particularly, compounds 4c, 4d, 4f, 4h, 4j, 4l, and 4m demonstrated superior antitumor activities against the aforementioned cell lines. Moreover, the apoptosis process in all the tested cells was induced by compounds 4c, 4d, 4h, 4l, and 4m, as observed by the Annexin V/PI double staining flow cytometric assay. The DNA flow, cytometric analysis revealed that these compounds prompted cell cycle arrest at the G2/M phases. Furthermore, the topoisomerase catalytic activity assays indicated that these compounds inhibited both the topoisomerase I and II enzymes.


Assuntos
Apoptose , Benzopiranos/química , Compostos Heterocíclicos com 2 Anéis/química , Micro-Ondas , Nitrilas/química , Inibidores da Topoisomerase/síntese química , Apoptose/efeitos dos fármacos , Benzopiranos/metabolismo , Benzopiranos/farmacologia , Linhagem Celular Tumoral , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Halogenação , Humanos , Relação Estrutura-Atividade , Inibidores da Topoisomerase/metabolismo , Inibidores da Topoisomerase/farmacologia
15.
Bioorg Chem ; 91: 103131, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31377387

RESUMO

For the development of novel anticancer agents, we designed and synthesized a total of 37 perimidine o-quinone derivatives containing the o-quinone group at the A or B ring and different substituents (alkyl groups, aryl groups or heterocycles) at the C ring of the compounds. The structure-activity relationships (SARs) were established based on the cytotoxicity data of compounds from the HL-60, Huh7, Hct116, and Hela cell lines. The cytotoxicity results showed that most compounds exhibited potent cytotoxicity. In particular, compound b-12 showed the best anti-proliferative activity (IC50 ≤ 1 µM) against four cancer cell lines and strong potency against the HL-60/MX2 (0.47 µM) cell line, which is resistant to Topo II poisons. Further studies showed that b-12 exhibited potent Topo IIα inhibitory activity (IC50 = 7.54 µM) compared with Topo I, which acted as a class of non-intercalative Topo IIα catalytic inhibitor by inhibiting the ATP binding site of Topo II. Cell apoptosis and cell cycle assays confirmed that b-12 could induce the apoptosis of Huh7 cells in a dose-dependent manner.


Assuntos
Antineoplásicos/farmacologia , Quinazolinas/farmacologia , Quinonas/farmacologia , Inibidores da Topoisomerase II/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , 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 , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Quinazolinas/síntese química , Quinazolinas/metabolismo , Quinonas/síntese química , Quinonas/metabolismo , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/metabolismo
16.
J Chem Inf Model ; 59(9): 4007-4017, 2019 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-31449404

RESUMO

Human type II topoisomerases (TopoII) are essential for controlling DNA topology within the cell. For this reason, there are a number of TopoII-targeted anticancer drugs that act by inducing DNA cleavage mediated by both TopoII isoforms (TopoIIα and TopoIIß) in cells. However, recent studies suggest that specific poisoning of TopoIIα may be a safer strategy for treating cancer. This is because poisoning of TopoIIß appears to be linked to the generation of secondary leukemia in patients. We recently reported that enzyme-mediated DNA cleavage complexes (in which TopoII is covalently linked to the cleaved DNA during catalysis) formed in the presence of the anticancer drug etoposide persisted approximately 3-fold longer with TopoIIα than TopoIIß. Notably, enhanced drug-target residence time may reduce the adverse effects of specific TopoIIα poisons. However, it is still not clear how to design drugs that are specific for the α isoform. In this study, we report the results of classical molecular dynamics (MD) simulations to comparatively analyze the molecular interactions formed within the TopoII/DNA/etoposide complex with both isoforms. We also used smoothed potential MD to estimate etoposide dissociation kinetics from the two isoform complexes. These extensive classical and enhanced sampling simulations revealed stabilizing interactions of etoposide with two serine residues (Ser763 and Ser800) in TopoIIα. These interactions are missing in TopoIIß, where both amino acids are alanine residues. This may explain the greater persistence of etoposide-stabilized cleavage complexes formed with Topo TopoIIα. These findings could be useful for the rational design of specific TopoIIα poisons.


Assuntos
Antineoplásicos/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Etoposídeo/metabolismo , Simulação de Dinâmica Molecular , Terapia de Alvo Molecular , Antineoplásicos/farmacologia , Domínio Catalítico , DNA Topoisomerases Tipo II/química , Etoposídeo/farmacologia , Humanos , Isoenzimas/química , Isoenzimas/metabolismo , Cinética
17.
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
Ciprofloxacina/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
18.
J Mol Biol ; 431(18): 3427-3449, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31301408

RESUMO

Type II topoisomerases regulate DNA topology by making a double-stranded break in one DNA duplex, transporting another DNA segment through this break and then resealing it. Bacterial type IIA topoisomerase inhibitors, such as fluoroquinolones and novel bacterial topoisomerase inhibitors, can trap DNA cleavage complexes with double- or single-stranded cleaved DNA. To study the mode of action of such compounds, 21 crystal structures of a "gyraseCORE" fusion truncate of Staphyloccocus aureus DNA gyrase complexed with DNA and diverse inhibitors have been published, as well as 4 structures lacking inhibitors. These structures have the DNA in various cleavage states and appear to track trajectories along the catalytic paths of the DNA cleavage/religation steps. The various conformations sampled by these multiple "gyraseCORE" structures show rigid body movements of the catalytic GyrA WHD and GyrB TOPRIM domains across the dimer interface. Conformational changes common to all compound-bound structures suggest common mechanisms for DNA cleavage-stabilizing compounds. The structures suggest that S. aureus gyrase uses a single moving-metal ion for cleavage and that the central four base pairs need to be stretched between the two catalytic sites, in order for a scissile phosphate to attract a metal ion to the A-site to catalyze cleavage, after which it is "stored" in another coordination configuration (B-site) in the vicinity. We present a simplified model for the catalytic cycle in which capture of the transported DNA segment causes conformational changes in the ATPase domain that push the DNA gate open, resulting in stretching and cleaving the gate-DNA in two steps.


Assuntos
Antibacterianos/farmacologia , Clivagem do DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/efeitos dos fármacos , DNA/química , Inibidores da Topoisomerase/farmacologia , Domínio Catalítico , DNA/metabolismo , DNA Girase/química , DNA Girase/genética , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/efeitos dos fármacos , Fluoroquinolonas/farmacologia , Metais , Modelos Moleculares , Conformação Proteica , Quinolonas , Staphylococcus aureus/enzimologia , Inibidores da Topoisomerase II/farmacologia
19.
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
20.
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
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