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1.
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
2.
Circ Res ; 126(8): 947-964, 2020 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-32091972

RESUMO

RATIONALE: Drug-induced proarrhythmia is so tightly associated with prolongation of the QT interval that QT prolongation is an accepted surrogate marker for arrhythmia. But QT interval is too sensitive a marker and not selective, resulting in many useful drugs eliminated in drug discovery. OBJECTIVE: To predict the impact of a drug from the drug chemistry on the cardiac rhythm. METHODS AND RESULTS: In a new linkage, we connected atomistic scale information to protein, cell, and tissue scales by predicting drug-binding affinities and rates from simulation of ion channel and drug structure interactions and then used these values to model drug effects on the hERG channel. Model components were integrated into predictive models at the cell and tissue scales to expose fundamental arrhythmia vulnerability mechanisms and complex interactions underlying emergent behaviors. Human clinical data were used for model framework validation and showed excellent agreement, demonstrating feasibility of a new approach for cardiotoxicity prediction. CONCLUSIONS: We present a multiscale model framework to predict electrotoxicity in the heart from the atom to the rhythm. Novel mechanistic insights emerged at all scales of the system, from the specific nature of proarrhythmic drug interaction with the hERG channel, to the fundamental cellular and tissue-level arrhythmia mechanisms. Applications of machine learning indicate necessary and sufficient parameters that predict arrhythmia vulnerability. We expect that the model framework may be expanded to make an impact in drug discovery, drug safety screening for a variety of compounds and targets, and in a variety of regulatory processes.


Assuntos
Antiarrítmicos/química , Arritmias Cardíacas/tratamento farmacológico , Cardiotoxinas/química , Simulação por Computador , Descoberta de Drogas/métodos , Canal de Potássio ERG1/química , Antiarrítmicos/metabolismo , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/metabolismo , Cardiotoxicidade/metabolismo , Cardiotoxicidade/prevenção & controle , Cardiotoxinas/efeitos adversos , Cardiotoxinas/metabolismo , Descoberta de Drogas/tendências , Canal de Potássio ERG1/metabolismo , Feminino , Humanos , Síndrome do QT Longo/tratamento farmacológico , Síndrome do QT Longo/metabolismo , Aprendizado de Máquina , Masculino , Moxifloxacina/química , Moxifloxacina/metabolismo , Moxifloxacina/uso terapêutico , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Fenetilaminas/química , Fenetilaminas/metabolismo , Fenetilaminas/uso terapêutico , Estrutura Secundária de Proteína , Sulfonamidas/química , Sulfonamidas/metabolismo , Sulfonamidas/uso terapêutico , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/uso terapêutico
3.
Int J Mol Sci ; 21(3)2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31979415

RESUMO

ABCG2 is one of a triumvirate of human multidrug ATP binding cassette (ABC) transporters that are implicated in the defense of cells and tissues against cytotoxic chemicals, but these transporters can also confer chemotherapy resistance states in oncology. Understanding the mechanism of ABCG2 is thus imperative if we are to be able to counter its deleterious activity. The structure of ABCG2 and its related family members (ABCG5/G8) demonstrated that there were two interfaces between the nucleotide binding domains (NBD). In addition to the canonical ATP "sandwich-dimer" interface, there was a second contact region between residues at the C-terminus of the NBD. We investigated this second interface by making mutations to a series of residues that are in close interaction with the opposite NBD. Mutated ABCG2 isoforms were expressed in human embryonic kidney (HEK) 293T cells and analysed for targeting to the membrane, drug transport, and ATPase activity. Mutations to this second interface had a number of effects on ABCG2, including altered drug specificity, altered drug transport, and, in two mutants, a loss of ATPase activity. The results demonstrate that this region is particularly sensitive to mutation and can impact not only direct, local NBD events (i.e., ATP hydrolysis) but also the allosteric communication to the transmembrane domains and drug transport.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/química , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Preparações Farmacêuticas/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/metabolismo , Animais , Transporte Biológico/genética , Embrião de Galinha , Clorofila/análogos & derivados , Clorofila/metabolismo , Resistência a Múltiplos Medicamentos/genética , Células HEK293 , Humanos , Hidrólise , Mitoxantrona/metabolismo , Mutação , Domínios Proteicos/genética , Inibidores da Topoisomerase II/metabolismo
4.
Mater Sci Eng C Mater Biol Appl ; 106: 110275, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753398

RESUMO

Etoposide (ETS), topoisomerase-II inhibitor, is a first-line anticancer therapeutics used in diverse cancer types. However, the therapeutic potential of this molecule has mainly impeded due to its detrimental toxicity profile, unfavorable rejection by the cancer cells due to P-glycoprotein (P-gp) efflux activity, and rapid hepatic clearance through extensive metabolism by Cytochrome-P450. To increase the therapeutic potency without significant adverse effects, the implication of novel ETS-nanoformulation strategies have recommended mainly. Nanomedicine based nanoformulation approaches based on nanoparticles (NPs), dendrimers, carbon-nanotubes (CNTs), liposomes, polymeric micelles, emulsions, dendrimers, solid-lipid NPs, etc offers immense potential opportunities to improve the therapeutic potential of pharmaceutically problematic drugs. This review provides an up-to-date argument on the work done in the field of nanomedicine to resolve pharmacokinetic and pharmacodynamic issues associated with ETS. The review also expounds the progress in regards to the regulatory, patenting and clinical trials related to the innovative formulation aspects of ETS.


Assuntos
Portadores de Fármacos/química , Etoposídeo/química , Nanopartículas/química , Inibidores da Topoisomerase II/química , Animais , Estabilidade de Medicamentos , Endocitose , Etoposídeo/metabolismo , Meia-Vida , Humanos , Solubilidade , Inibidores da Topoisomerase II/metabolismo
5.
Bioorg Chem ; 93: 103309, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31585266

RESUMO

The antibacterial agents and therapies today are facing serious problems such as drug resistance. Introducing dual inhibiting effect is a valid approach to solve this trouble and bring advantages including wide adaptability, favorable safety and superiority of combination. We started from potential DNA Gyrase inhibitory backbone isatin to develop oxoindolin derivatives as atypical dual Gyrase (major) and FabH (assistant) inhibitors via a two-round screening. Aiming at blocking both duplication (Gyrase) and survival (FabH), most of synthesized compounds indicated potency against Gyrase and some of them inferred favorable inhibitory effect on FabH. The top hit I18 suggested comparable Gyrase inhibitory activity (IC50 = 0.025 µM) and antibacterial effect with the positive control Novobiocin (IC50 = 0.040 µM). FabH inhibitory activity (IC50 = 5.20 µM) was also successfully introduced. Docking simulation hinted possible important interacted residues and binding patterns for both target proteins. Adequate Structure-Activity Relation discussions provide the future orientations of modification. With high potency, low initial toxicity and dual inhibiting strategy, advanced compounds with therapeutic methods will be developed for clinical application.


Assuntos
Acetiltransferases/antagonistas & inibidores , DNA Girase/química , Proteínas de Escherichia coli/antagonistas & inibidores , Indóis/química , Inibidores da Topoisomerase II/química , Acetiltransferases/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Sítios de Ligação , DNA Girase/metabolismo , Avaliação Pré-Clínica de Medicamentos , Escherichia coli/enzimologia , Proteínas de Escherichia coli/metabolismo , Ácido Graxo Sintase Tipo II/antagonistas & inibidores , Ácido Graxo Sintase Tipo II/metabolismo , Indóis/metabolismo , Indóis/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/farmacologia
6.
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
7.
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
8.
Cell Chem Biol ; 26(9): 1274-1282.e4, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31279606

RESUMO

Common approaches to antibiotic discovery include small-molecule screens for growth inhibition in target pathogens and screens for inhibitors of purified enzymes. These approaches have a shared intent of seeking to directly target a vital Achilles heel in a pathogen of interest. Here, we report the first screen against a sporulation pathway in a non-pathogenic bacterium as a means of discovering novel antibiotics-this effort has resulted in two important discoveries. First, we show that the sporulation program of Streptomyces venezuelae is exquisitely sensitive to numerous forms of DNA damage. Second, we have identified a DNA gyrase inhibitor. This molecule, EN-7, is active against pathogenic species that are resistant to ciprofloxacin and other clinically important antibiotics. We suggest that this strategy could be applied to other morphogenetic pathways in prokaryotes or eukaryotes as a means of identifying novel chemical matter having scientific and clinical utility.


Assuntos
DNA Girase/efeitos dos fármacos , Descoberta de Drogas/métodos , Inibidores da Topoisomerase II/isolamento & purificação , Antibacterianos/farmacologia , DNA Girase/metabolismo , Testes de Sensibilidade Microbiana , Esporos Bacterianos/efeitos dos fármacos , Streptomyces/efeitos dos fármacos , Streptomyces/metabolismo , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/farmacologia
9.
Eur J Med Chem ; 175: 330-348, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096154

RESUMO

Human DNA topoisomerases represent one of the key targets of modern chemotherapy. An emerging group of catalytic inhibitors of human DNA topoisomerase IIα comprises a new paradigm directed to circumvent the known limitations of topoisomerase II poisons such as cardiotoxicity and induction of secondary tumors. In our previous studies, 4,6-substituted-1,3,5-triazin-2(1H)-ones were discovered as catalytic inhibitors of topo IIα. Here, we report the results of our efforts to optimize several properties of the initial chemical series that did not exhibit cytotoxicity on cancer cell lines. Using an optimized synthetic route, a focused chemical library was designed aimed at further functionalizing substituents at the position 4 of the 1,3,5-triazin-2(1H)-one scaffold to enable additional interactions with the topo IIα ATP binding site. After virtual screening, selected 36 analogues were synthesized and experimentally evaluated for human topo IIα inhibition. The optimized series displayed improved inhibition of topo IIα over the initial series and the catalytic mode of inhibition was confirmed for the selected active compounds. The optimized series also showed cytotoxicity against HepG2 and MCF-7 cell lines and did not induce double-strand breaks, thus displaying a mechanism of action that differs from the topo II poisons on the cellular level. The new series represents a new step in the development of the 4,6-substituted-1,3,5-triazin-2(1H)-one class towards novel efficient anticancer therapies utilizing the catalytic topo IIα inhibition paradigm.


Assuntos
DNA Topoisomerases Tipo II/efeitos dos fármacos , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia , Triazinas/química , Triazinas/farmacologia , Trifosfato de Adenosina/metabolismo , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Catálise , Quebras de DNA de Cadeia Dupla , Células Hep G2 , Histonas/metabolismo , Humanos , Células MCF-7 , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/metabolismo
10.
J Med Chem ; 62(9): 4411-4425, 2019 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-31009558

RESUMO

Expression of ß-lactamase is the single most prevalent determinant of antibiotic resistance, rendering bacteria resistant to ß-lactam antibiotics. In this article, we describe the development of an antibiotic prodrug that combines ciprofloxacin with a ß-lactamase-cleavable motif. The prodrug is only bactericidal after activation by ß-lactamase. Bactericidal activity comparable to ciprofloxacin is demonstrated against clinically relevant E. coli isolates expressing diverse ß-lactamases; bactericidal activity was not observed in strains without ß-lactamase. These findings demonstrate that it is possible to exploit antibiotic resistance to selectively target ß-lactamase-producing bacteria using our prodrug approach, without adversely affecting bacteria that do not produce ß-lactamase. This paves the way for selective targeting of drug-resistant pathogens without disrupting or selecting for resistance within the microbiota, reducing the rate of secondary infections and subsequent antibiotic use.


Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Ciprofloxacino/análogos & derivados , Ciprofloxacino/farmacologia , Pró-Fármacos/farmacologia , beta-Lactamases/metabolismo , Antibacterianos/síntese química , Antibacterianos/metabolismo , Cefalosporinas/síntese química , Cefalosporinas/metabolismo , Ciprofloxacino/metabolismo , Resistência Microbiana a Medicamentos/fisiologia , Escherichia coli/efeitos dos fármacos , Hidrólise , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pró-Fármacos/síntese química , Pró-Fármacos/metabolismo , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/farmacologia
11.
Mol Biol Rep ; 46(4): 3625-3636, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31020489

RESUMO

Topoisomerase II (Topo2) inhibitors in combination with cisplatin represent a common treatment modality used for glioma patients. The main mechanism of their action involves induction of DNA double-strand breaks (DSBs). DSBs are repaired via the homology-dependent DNA repair (HRR) and non-homologous end-joining (NHEJ). Inhibition of the NHEJ or HRR pathway sensitizes cancer cells to the treatment. In this work, we investigated the effect of three Topo2 inhibitors-etoposide, NK314, or HU-331 in combination with cisplatin in the U-87 human glioblastoma cell line. Etoposide as well as NK314 inhibited Topo2 activity by stabilizing Topo2-DNA cleavable complexes whereas HU-331 inhibited the ATPase activity of Topo2 using a noncompetitive mechanism. To increase the effectiveness of the treatment, we combined cisplatin and Topo2 inhibitor treatment with DSB repair inhibitors (DRIs). The cells were sensitized with NHEJ inhibitor, NU7441, or the novel HRR inhibitor, YU238259, prior to drug treatment. All of the investigated Topo2 inhibitors in combination with cisplatin efficiently killed the U-87 cells. The most cytotoxic effect was observed for the cisplatin + HU331 treatment scheme and this effect was significantly increased when a DRI pretreatment was used; however, we did not observed DSBs. Therefore, the molecular mechanism of cytotoxicity caused by the cisplatin + HU331 treatment scheme is yet to be evaluated. We observed a concentration-dependent change in DSB levels and accumulation at the G2/M checkpoint and S-phase in glioma cells incubated with NK314/cisplatin and etoposide/cisplatin. In conclusion, in combination with cisplatin, HU331 is the most potent Topo2 inhibitor of human glioblastoma cells.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Cisplatino/farmacologia , Glioblastoma/tratamento farmacológico , Fenantrenos/farmacologia , Inibidores da Topoisomerase II/farmacologia , Apoptose/efeitos dos fármacos , Benzamidas/farmacologia , Neoplasias Encefálicas/metabolismo , Canabidiol/análogos & derivados , Canabidiol/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cromonas/farmacologia , Quebras de DNA de Cadeia Dupla , Reparo do DNA/efeitos dos fármacos , Etoposídeo/farmacologia , Glioblastoma/metabolismo , Humanos , Morfolinas/farmacologia , Sulfonamidas/farmacologia , Inibidores da Topoisomerase II/metabolismo
12.
Bioorg Chem ; 85: 308-318, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30654222

RESUMO

A series of new 1,2,4-triazole and 1,3,4-oxadiazole derivatives was obtained via several steps sequential reactions of phenyl piperazine. Then, these compounds were converted to the corresponding fluoroquinolone hybrids via one pot three component Mannich reaction. All the reactions were examined under conventional and microwave mediated conditions, and optimum conditions were determined. The effect of different solvents and microwave power on microwave prompted reactions was investigated as well. All the newly synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR and EI MS spectral techniques. The antimicrobial activity, DNA gyrase and Topoisomerase IV inhibition potentials were performed. The results obtained showed that fluoroquinolone hybrids possess good antimicrobial activity. Moreover, Fluoroquinolone-azole-piperazine hybrids synthesized in the present study displayed excellent DNA gyrase inhibition. To unveil the interaction mode of compounds to receptor, a molecular docking study was performed. With an average least binding energy of -9.5 kcal/mol, all compounds were found to have remarkable inhibitory potentials against DNA gyrase (E. coli).


Assuntos
Antibacterianos/farmacologia , Fluoroquinolonas/farmacologia , Piperazinas/farmacologia , Triazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/metabolismo , DNA Girase/metabolismo , DNA Topoisomerase IV/antagonistas & inibidores , DNA Topoisomerase IV/metabolismo , Enterococcus faecalis/efeitos dos fármacos , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/metabolismo , Fluoroquinolonas/síntese química , Fluoroquinolonas/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/enzimologia , Testes de Sensibilidade Microbiana , Micro-Ondas , Simulação de Acoplamento Molecular , Piperazinas/síntese química , Piperazinas/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/farmacologia , Triazóis/síntese química , Triazóis/metabolismo
13.
Mol Cell ; 73(4): 749-762.e5, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30661981

RESUMO

The introduction of azole heterocycles into a peptide backbone is the principal step in the biosynthesis of numerous compounds with therapeutic potential. One of them is microcin B17, a bacterial topoisomerase inhibitor whose activity depends on the conversion of selected serine and cysteine residues of the precursor peptide to oxazoles and thiazoles by the McbBCD synthetase complex. Crystal structures of McbBCD reveal an octameric B4C2D2 complex with two bound substrate peptides. Each McbB dimer clamps the N-terminal recognition sequence, while the C-terminal heterocycle of the modified peptide is trapped in the active site of McbC. The McbD and McbC active sites are distant from each other, which necessitates alternate shuttling of the peptide substrate between them, while remaining tethered to the McbB dimer. An atomic-level view of the azole synthetase is a starting point for deeper understanding and control of biosynthesis of a large group of ribosomally synthesized natural products.


Assuntos
Antibacterianos/biossíntese , Proteínas de Bactérias/metabolismo , Bacteriocinas/biossíntese , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Complexos Multienzimáticos/metabolismo , Ribossomos/enzimologia , Inibidores da Topoisomerase II/metabolismo , Antibacterianos/química , Antibacterianos/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Bacteriocinas/química , Bacteriocinas/farmacologia , Sítios de Ligação , Cristalografia por Raios X , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Modelos Moleculares , Complexos Multienzimáticos/química , Complexos Multienzimáticos/genética , Mutação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Estrutura Quaternária de Proteína , Ribossomos/efeitos dos fármacos , Ribossomos/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia , Difração de Raios X
14.
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
15.
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
16.
Mol Microbiol ; 111(2): 441-454, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30427086

RESUMO

Toxin-antitoxin systems are mediators of diverse activities in bacterial physiology. For the ParE-type toxins, their reported role of gyrase inhibition utilized during plasmid-segregation killing indicates they are toxic. However, their location throughout chromosomes leads to questions about function, including potential non-toxic outcomes. The current study has characterized a ParDE system from the opportunistic human pathogen Pseudomonas aeruginosa (Pa). We identified a protective function for this ParE toxin, PaParE, against effects of quinolone and other antibiotics. However, higher concentrations of PaParE are themselves toxic to cells, indicating the phenotypic outcome can vary based on its concentration. Our assays confirmed PaParE inhibition of gyrase-mediated supercoiling of DNA with an IC50 value in the low micromolar range, a species-specificity that resulted in more efficacious inhibition of Escherichia coli derived gyrase versus Pa gyrase, and overexpression in the absence of antitoxin yielded an expected filamentous morphology with multi-foci nucleic acid material. Additional data revealed that the PaParE toxin is monomeric and interacts with dimeric PaParD antitoxin with a KD in the lower picomolar range, yielding a heterotetramer. This work provides novel insights into chromosome-encoded ParE function, whereby its expression can impart partial protection to cultures from selected antibiotics.


Assuntos
Antibacterianos/metabolismo , Toxinas Bacterianas/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Inibidores da Topoisomerase II/metabolismo , Sistemas Toxina-Antitoxina , Escherichia coli/citologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Concentração Inibidora 50 , Pseudomonas aeruginosa/citologia , Quinolonas/farmacologia
17.
Sci Rep ; 8(1): 14827, 2018 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-30287851

RESUMO

Telomere maintenance by telomerase activity supports the infinite growth of cancer cells. MST-312, a synthetic telomerase inhibitor, gradually shortens telomeres at non-acute lethal doses and eventually induces senescence and apoptosis of telomerase-positive cancer cells. Here we report that MST-312 at higher doses works as a dual inhibitor of telomerase and DNA topoisomerase II and exhibits acute anti-proliferative effects on cancer cells and xenografted tumours in vivo. Our cell-based chemical fingerprinting approach revealed that cancer cells with shorter telomeres and lower expression of lamin A, a nuclear architectural protein, exhibited higher sensitivity to the acute deleterious effects of MST-312, accompanied by formation of telomere dysfunction-induced foci and DNA double-strand breaks. Telomere elongation and lamin A overexpression attenuated telomeric and non-telomeric DNA damage, respectively, and both conferred resistance to apoptosis induced by MST-312 and other DNA damaging anticancer agents. These observations suggest that sufficient pools of telomeres and a nuclear lamina component contribute to the cellular robustness against DNA damage induced by therapeutic treatment in human cancer cells.


Assuntos
Proliferação de Células , Dano ao DNA , Reparo do DNA , Lamina Tipo A/metabolismo , Neoplasias/patologia , Telômero/metabolismo , Células Artificiais , Benzamidas/metabolismo , Linhagem Celular Tumoral , Inibidores Enzimáticos/metabolismo , Humanos , Mapeamento de Peptídeos , Sensibilidade e Especificidade , Telomerase/antagonistas & inibidores , Inibidores da Topoisomerase II/metabolismo
18.
ChemMedChem ; 13(24): 2635-2643, 2018 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-30347518

RESUMO

Chemotherapy is used for the treatment of all stages of breast cancer, including the metastatic stage of the disease. Treatment regimens are generally tailored for each patient's particular situation. However, chemotherapeutic agents are the leading cause of serious drug-related adverse effects; moreover, drug resistance often occurs. In this study, we designed and synthesized a new series of N-alkylcarbazoles derived from ellipticine, an alkaloid with a carbazole skeleton initially used in the treatment of metastatic breast cancer and later dismissed because of poor aqueous solubility and severe side effects. After evaluating the binding modes of our class of newly synthesized compounds with human topoisomerase II (hTopo II), we performed hTopo II decatenation assays, identifying compound 4 f (2-(4-((3-chloro-9H-carbazol-9-yl)pentyl)piperazin-1-yl)-N,N,N-trimethylethanammonium iodide) as a good inhibitor. Moreover, 4 f and 4 g (2-(4-((3-chloro-9H-carbazol-9-yl)hexyl)piperazin-1-yl)-N,N,N-trimethylethanammonium iodide) showed a good anti-proliferative activity toward breast cancer cells, causing apoptosis by activation of the caspase pathway. Interestingly, the activity of these two compounds on triple-negative MDA-MB-231 cells, which tend to be highly metastatic and aggressive, is strictly connected to the observed inhibition of hTopo II.


Assuntos
Antineoplásicos/química , Carbazóis/química , DNA Topoisomerases Tipo II/metabolismo , Elipticinas/química , Compostos de Amônio Quaternário/química , Inibidores da Topoisomerase II/síntese química , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama , Carbazóis/síntese química , Carbazóis/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Elipticinas/síntese química , Elipticinas/farmacologia , Feminino , Humanos , Simulação de Acoplamento Molecular , Compostos de Amônio Quaternário/síntese química , Compostos de Amônio Quaternário/farmacologia , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/metabolismo , Inibidores da Topoisomerase II/farmacologia
19.
Sci Rep ; 8(1): 9685, 2018 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-29946146

RESUMO

The unique biology of the oocyte means that accepted paradigms for DNA repair and protection are not of direct relevance to the female gamete. Instead, preservation of the integrity of the maternal genome depends on endogenous protein stores and/or mRNA transcripts accumulated during oogenesis. The aim of this study was to determine whether mature (MII) oocytes have the capacity to detect DNA damage and subsequently mount effective repair. For this purpose, DNA double strand breaks (DSB) were elicited using the topoisomerase II inhibitor, etoposide (ETP). ETP challenge led to a rapid and significant increase in DSB (P = 0.0002) and the consequential incidence of metaphase plate abnormalities (P = 0.0031). Despite this, ETP-treated MII oocytes retained their ability to participate in in vitro fertilisation, though displayed reduced developmental competence beyond the 2-cell stage (P = 0.02). To account for these findings, we analysed the efficacy of DSB resolution, revealing a significant reduction in DSB lesions 4 h post-ETP treatment. Notably, this response was completely abrogated by pharmacological inhibition of key elements (DNA-PKcs and DNA ligase IV) of the canonical non-homologous end joining DNA repair pathway, thus providing the first evidence implicating this reparative cascade in the protection of the maternal genome.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA/fisiologia , Oócitos/metabolismo , Animais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA/genética , Etoposídeo/farmacologia , Camundongos , Oócitos/efeitos dos fármacos , Inibidores da Topoisomerase II/metabolismo
20.
Toxicol Lett ; 294: 184-192, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29803840

RESUMO

Doxorubicin (DOX) is a chemotherapeutic agent of which the medical use is limited due to cardiotoxicity. While acute cardiotoxicity is reversible, chronic cardiotoxicity is persistent or progressive, dose-dependent and irreversible. While DOX mechanisms of action are not fully understood yet, 3 toxicity processes are known to occur in vivo: cardiomyocyte dysfunction, mitochondrial dysfunction and cell death. We present an in vitro experimental design aimed at detecting DOX-induced cardiotoxicity by obtaining a global view of the induced molecular mechanisms through RNA-sequencing. To better reflect the in vivo situation, human 3D cardiac microtissues were exposed to physiologically-based pharmacokinetic (PBPK) relevant doses of DOX for 2 weeks. We analysed a therapeutic and a toxic dosing profile. Transcriptomics analysis revealed significant gene expression changes in pathways related to "striated muscle contraction" and "respiratory electron transport", thus suggesting mitochondrial dysfunction as an underlying mechanism for cardiotoxicity. Furthermore, expression changes in mitochondrial processes differed significantly between the doses. Therapeutic dose reflects processes resembling the phenotype of delayed chronic cardiotoxicity, while toxic doses resembled acute cardiotoxicity. Overall, these results demonstrate the capability of our innovative in vitro approach to detect the three known mechanisms of DOX leading to toxicity, thus suggesting its potential relevance for reflecting the patient situation. Our study also demonstrated the importance of applying physiologically relevant doses during toxicological research, since mechanisms of acute and chronic toxicity differ.


Assuntos
Cardiotoxinas/efeitos adversos , Doxorrubicina/efeitos adversos , Ventrículos do Coração/efeitos dos fármacos , Modelos Biológicos , Miócitos Cardíacos/efeitos dos fármacos , Esferoides Celulares/efeitos dos fármacos , Inibidores da Topoisomerase II/efeitos adversos , Antibióticos Antineoplásicos/efeitos adversos , Antibióticos Antineoplásicos/metabolismo , Cardiotoxinas/metabolismo , Células Cultivadas , Doxorrubicina/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Ventrículos do Coração/citologia , Ventrículos do Coração/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Metabolômica/métodos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Concentração Osmolar , Análise de Sequência de RNA , Esferoides Celulares/citologia , Esferoides Celulares/metabolismo , Fatores de Tempo , Técnicas de Cultura de Tecidos , Inibidores da Topoisomerase II/metabolismo , Testes de Toxicidade Aguda/métodos , Testes de Toxicidade Crônica/métodos
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