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1.
Anticancer Agents Med Chem ; 19(11): 1350-1358, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30961512

RESUMO

BACKGROUND: 9-anilinoacridines are acting as DNA-intercalating agents which plays an important role as antitumor drugs, due to their anti-proliferative properties. Some anticancer agents contain 9- anilinoacridines such as amsacrine (m-AMSA), and nitracrine (Ledakrine) have been already developed. METHODS: In this study, novel 9-anilinoacridines substituted with thiazines 4a-r were designed, synthesized, characterized by physical and spectral data and their cytotoxic activities against DLA cell lines were evaluated. RESULTS: Among those compounds, 4b, c, e, g, i, j, k, m, o, p, q, r exhibited significant short term in vitro cytotoxic activity against Daltons lymphoma ascites (DLA) cells with CTC50 value of 0.18 to 0.31µM. The compounds 4b, c, e, g, i, j, k, m, o, p, q, r are also exhibited significant long term in vitro anti-tumour activity against human tumor cell lines, HEp-2 (laryngeal epithelial carcinoma) by Sulforhodamine B assay with CTC50 value of 0.20 to 0.39µM. The compounds 4b, i, j exhibited significant in vivo antitumor activity with % Increase in Life Span (ILS) 48-82%. CONCLUSION: Results obtained in this study clearly demonstrated that many of the thiazine substituted 9- anilinoacridines exert interesting anti-tumour activity. The compounds 4b, i, j have significant anti-tumour activity and useful drugs after further refinement. The above derivatives will encourage to design future antitumor agents with high therapeutic potentials.


Assuntos
Amsacrina/análogos & derivados , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Tiazinas/farmacologia , Amsacrina/síntese química , Amsacrina/química , Amsacrina/farmacologia , Animais , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Camundongos , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Relação Estrutura-Atividade , Tiazinas/química , Células Tumorais Cultivadas
2.
Drug Deliv ; 25(1): 611-622, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29493300

RESUMO

To improve drug retention in carriers for amphiphilic asulacrine (ASL), a novel active loading method using micelle gradient was developed to fabricate the ASL-loaded multiseed liposomes (ASL-ML). The empty ML were prepared by hydrating a thin film with empty micelles. Then the micelles in liposomal compartment acting as 'micelle pool' drove the drug to be loaded after the outer micelles were removed. Some reasoning studies including critical micelle concentration (CMC) determination, influencing factors tests on entrapment efficiency (EE), structure visualization, and drug release were carried out to explore the mechanism of active loading, ASL location, and the structure of ASL-ML. Comparisons were made between pre-loading and active loading method. Finally, the extended drug retention capacity of ML was evaluated through pharmacokinetic, drug tissue irritancy, and in vivo anti-tumor activity studies. Comprehensive results from fluorescent and transmission electron microscope (TEM) observation, encapsulation efficiency (EE) comparison, and release studies demonstrated the formation of ML-shell structure for ASL-ML without inter-carrier fusion. The location of drug mainly in inner micelles as well as the superiority of post-loading to the pre-loading method , in which drug in micelles shifted onto the bilayer membrane was an additional positive of this delivery system. It was observed that the drug amphiphilicity and interaction of micelles with drug were the two prerequisites for this active loading method. The extended retention capacity of ML has been verified through the prolonged half-life, reduced paw-lick responses in rats, and enhanced tumor inhibition in model mice. In conclusion, ASL-ML prepared by active loading method can effectively load drug into micelles with expected structure and improve drug retention.


Assuntos
Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Micelas , Tensoativos/administração & dosagem , Carga Tumoral/efeitos dos fármacos , Amsacrina/administração & dosagem , Amsacrina/análogos & derivados , Amsacrina/farmacocinética , Animais , Antineoplásicos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Lipossomos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Sprague-Dawley , Tensoativos/farmacocinética , Resultado do Tratamento , Carga Tumoral/fisiologia
3.
Pharm Res ; 35(1): 13, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29302821

RESUMO

PURPOSE: To enhance therapeutic efficacy and prevent phlebitis caused by Asulacrine (ASL) precipitation post intravenous injection, ASL-loaded hybrid micelles with size below 40 nm were developed to improve drug retention and tumor penetration. METHODS: ASL-micelles were prepared using different weight ratios of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethyleneglycol-2000 (DSPE-PEG2000) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) polymers. Stability of micelles was optimized in terms of critical micelle concentration (CMC) and drug release properties. The encapsulation efficiency (EE) and drug loading were determined using an established dialysis-mathematic fitting method. Multicellular spheroids (MCTS) penetration and cytotoxicity were investigated on MCF-7 cell line. Pharmacokinetics of ASL-micelles was evaluated in rats with ASL-solution as control. RESULTS: The ASL-micelles prepared with DSPE-PEG2000 and TPGS (1:1, w/w) exhibited small size (~18.5 nm), higher EE (~94.12%), better sustained in vitro drug release with lower CMC which may be ascribed to the interaction between drug and carriers. Compared to free ASL, ASL-micelles showed better MCTS penetration capacity and more potent cytotoxicity. Pharmacokinetic studies demonstrated that the half-life and AUC values of ASL-micelles were approximately 1.37-fold and 3.49-fold greater than that of free ASL. CONCLUSIONS: The optimized DSPE-PEG2000/TPGS micelles could serve as a promising vehicle to improve drug retention and penetration in tumor.


Assuntos
Amsacrina/análogos & derivados , Antineoplásicos/farmacocinética , Micelas , Fosfatidiletanolaminas/química , Polietilenoglicóis/química , Amsacrina/química , Amsacrina/farmacocinética , Amsacrina/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Técnicas de Cultura de Células , Sobrevivência Celular , Preparações de Ação Retardada , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Meia-Vida , Humanos , Células MCF-7 , Masculino , Nanopartículas/química , Tamanho da Partícula , Permeabilidade , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície , Vitamina E/química
4.
J Mol Graph Model ; 72: 209-219, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28110185

RESUMO

Amsacrine is an effective topoisomerase II enzyme inhibitor in acute lymphatic leukemia. Previous experimental studies have successfully identified two important mutations (R487K and E571K) conferring 100 and 25 fold resistance to Amsacrine respectively. Although the reduction of the cleavage ligand-DNA-protein ternary complex has been well thought as the major cause of drug resistance, the detailed energetic, structural and dynamic mechanisms remain to be elusive. In this study, we constructed human topoisomerase II alpha (hTop2α) homology model docked with Amsacrine based on crystal structure of human Top2ß in complex with etoposide. This wild type complex was used to build the ternary complex with R487K and E571K mutants. Three 500ns molecular dynamics simulations were performed on complex systems of wild type and two mutants. The detailed energetic, structural and dynamic analysis were performed on the simulation data. Our binding data indicated a significant impairment of Amsacrine binding energy in the two mutants compared with the wild type. The order of weakening (R487K>E571K) was in agreement with the order of experimental drug resistance fold (R489K>E571K). Our binding energy decomposition further indicated that weakening of the ligand-protein interaction rather than the ligand-DNA interaction was the major contributor of the binding energy difference between R487K and E571K. In addition, key residues contributing to the binding energy (ΔG) or the decrease of the binding energy (ΔΔG) were identified through the energy decomposition analysis. The change in ligand binding pose, dynamics of protein, DNA and ligand upon the mutations were thoroughly analyzed and discussed. Deciphering the molecular basis of drug resistance is crucial to overcome drug resistance using rational drug design.


Assuntos
Amsacrina/química , DNA Topoisomerases Tipo II/genética , Resistencia a Medicamentos Antineoplásicos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mutação/genética , Solventes/química , Homologia Estrutural de Proteína , Amsacrina/farmacologia , DNA/química , Humanos , Proteínas Mutantes/química , Conformação Proteica , Termodinâmica
5.
Apoptosis ; 22(3): 406-420, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27757735

RESUMO

Previous studies have attributed the anticancer activity of amsacrine to its inhibitory effect on topoisomerase II. However, 9-aminoacridine derivatives, which have the same structural scaffold as amsacrine, induce cancer cell apoptosis by altering the expression of BCL2 family proteins. Therefore, in the present study, we assessed whether BCL2 family proteins mediated the cytotoxic effects of amsacrine on human leukemia U937 cells. Amsacrine-induced apoptosis of U937 cells was characterized by caspase-9 and caspase-3 activation, increased intracellular Ca2+ concentration, mitochondrial depolarization, and MCL1 down-regulation. Amsacrine induced MCL1 down-regulation by decreasing its stability. Further, amsacrine-treated U937 cells showed AKT degradation and Ca2+-mediated ERK inactivation. Blockade of ERK-mediated phosphorylation of MCL1 inhibited the effect of Pin1 on the stabilization of MCL1, and AKT degradation promoted GSK3ß-mediated degradation of MCL1. Restoration of ERK phosphorylation and AKT expression abrogated amsacrine-induced MCL1 down-regulation. Moreover, MCL1 over-expression inhibited amsacrine-induced depolarization of mitochondria membrane and increased the viability of amsacrine-treated cells. Taken together, our data indicate that amsacrine abolishes ERK- and Pin1-mediated stabilization of MCL1 and promotes GSK3ß-mediated degradation of MCL1, leading to activate mitochondria-mediated apoptosis pathway in U937 cells.


Assuntos
Amsacrina/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Cálcio/metabolismo , Etoposídeo/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Peptidilprolil Isomerase de Interação com NIMA/antagonistas & inibidores , Fosforilação/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/metabolismo , Células U937
6.
J Biomol Struct Dyn ; 35(6): 1260-1271, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27064820

RESUMO

The binding of the anilido aminoacridine derivative amsacrine with the heme proteins, hemoglobin, and myoglobin, was characterized by various spectroscopic and calorimetric methods. The binding affinity to hemoglobin was (1.21 ± .05) × 105 M-1, while that to myoglobin was three times higher (3.59 ± .15) × 105 M-1. The temperature-dependent fluorescence study confirmed the formation of ground-state complexes with both the proteins. The stronger binding to myoglobin was confirmed from both spectroscopic and calorimetric studies. The binding was exothermic in both cases at the three temperatures studied, and was favored by both enthalpy and entropy changes. Circular dichroism results, three-dimensional (3D) and synchronous fluorescence studies confirmed that the binding of amsacrine significantly changed the secondary structure of hemoglobin, while the change in the secondary structure of myoglobin was much less. New insights, in terms of structural and energetic aspects of the interaction of amsacrine with the heme proteins, presented here may help in understanding the structure-activity relationship, therapeutic efficacy, and drug design aspects of acridines.


Assuntos
Amsacrina/química , Calorimetria , Hemoglobinas/química , Mioglobina/química , Análise Espectral , Amsacrina/metabolismo , Calorimetria/métodos , Hemoglobinas/metabolismo , Humanos , Ligantes , Estrutura Molecular , Mioglobina/metabolismo , Ligação Proteica , Análise Espectral/métodos , Termodinâmica
7.
Bioorg Med Chem Lett ; 27(3): 586-589, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27998679

RESUMO

A number of topoisomerase II-targeted anticancer drugs, including amsacrine, utilize an acridine or related aromatic core as a scaffold. Therefore, to further explore the potential of acridine-related compounds to act as topoisomerase II poisons, we synthesized a series of novel trifluoromethylated 9-amino-3,4-dihydroacridin-1(2H)-one derivatives and examined their ability to enhance DNA cleavage mediated by human topoisomerase IIα. Derivatives containing a H, Cl, F, and Br at C7 enhanced enzyme-mediated double-stranded DNA cleavage ∼5.5- to 8.5-fold over baseline, but were less potent than amsacrine. The inclusion of an amino group at C9 was critical for activity. The compounds lost their activity against topoisomerase IIα in the presence of a reducing agent, displayed no activity against the catalytic core of topoisomerase IIα, and inhibited DNA cleavage when incubated with the enzyme prior to the addition of DNA. These findings strongly suggest that the compounds act as covalent, rather than interfacial, topoisomerase II poisons.


Assuntos
Acridinas/química , Acridinas/farmacologia , Antígenos de Neoplasias/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Amsacrina/química , Antineoplásicos/química , Antineoplásicos/farmacologia , DNA/metabolismo , Clivagem do DNA/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Substâncias Intercalantes/química , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia
8.
Biol Blood Marrow Transplant ; 23(2): 278-284, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27816650

RESUMO

Post-transplant relapse is the leading cause of treatment failure in acute myeloid leukemia (AML) patients after reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation (allo-HSCT). To improve their outcome, we evaluated the outcome of a sequential intermediate-intensity conditioning regimen combining fludarabine, cytosine arabinoside, amsacrine, cyclophosphamide, and either total body irradiation or busulfan (FLAMSA) in patients with intermediate or high-risk AML in first or second complete remission (CR). A total of 265 patients (median age, 55 years; range, 19 to 76) with AML who underwent allo-HSCT using a FLAMSA regimen were included. At the time of transplant, 216 (81.5%) were in CR1 and 49 (18.5%) in CR2. Cytogenetic was intermediate in 114 (43%) and poor in 42 (15.8%) patients, whereas 109 patients (41.1%) had a secondary AML. With a median follow-up of 46 months (range, 1 to 145), the Kaplan-Meier estimate of overall and leukemia-free survival at 2 years were 56.1% (95% CI, 49.7% to 62.6%) and 52.8% (95% CI, 46.4% to 59.2%), respectively. At 2 years, the cumulative incidences of relapse and nonrelapse mortality were 22.8% (95% CI, 17.6% to 28.4%) and 24.0% (95% CI, 18.8% to 29.5%), respectively. In multivariate analysis, patient age and cytogenetics were the only parameters with a significant impact on overall survival. These data suggest that the FLAMSA sequential intermediate conditioning regimen provides an efficient disease control in intermediate- and high-risk AML patients, including those in CR2 and with secondary AML.


Assuntos
Transplante de Medula Óssea , Leucemia Mieloide Aguda/terapia , Transplante de Células-Tronco de Sangue Periférico , Condicionamento Pré-Transplante/métodos , Adolescente , Adulto , Idoso , Aloenxertos , Amsacrina/administração & dosagem , Transplante de Medula Óssea/efeitos adversos , Bussulfano/administração & dosagem , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro/etiologia , Histocompatibilidade , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Modelos de Riscos Proporcionais , Indução de Remissão , Estudos Retrospectivos , Risco , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados , Irradiação Corporal Total , Adulto Jovem
9.
Curr Cancer Drug Targets ; 17(7): 657-668, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27834128

RESUMO

BACKGROUND: DNA topoisomerase II-α (Top2-α), an essential enzyme for the management of DNA during replication, transcription, recombination, and chromatin remodeling, is one of the most important anticancer targets. Numerous molecules have been designed as Top2-α inhibitors. However, several studies have shown that polymorphisms and mutations in Top2 have conferred resistance to most of these anticancer drugs. The aim of this study was to computationally examine the mechanisms by which genomic variations in Top2-α could affect its resistance to Amsacrine and Mitoxantrone as important inhibitors of the enzyme. RESULTS: The results showed that variants K529E, R568H, R568G and T530M could affect Top2-α inhibition by Amsacrine causing possible drug-resistant. Moreover, R487K, and Y481C variants could change the response of the enzyme to Mitoxantrone. CONCLUSION: These results could facilitate the prediction and development of more effective drugs for Top2-α variants, making the cancer chemotherapy more effectiv.


Assuntos
Amsacrina/química , DNA Topoisomerases Tipo II/química , DNA Topoisomerases Tipo II/genética , Mitoxantrona/química , Proteínas de Ligação a Poli-ADP-Ribose/química , Proteínas de Ligação a Poli-ADP-Ribose/genética , Polimorfismo de Nucleotídeo Único , Amsacrina/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Simulação por Computador , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Mitoxantrona/farmacologia , Simulação de Acoplamento Molecular , Conformação Proteica , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia
10.
Crit Rev Oncol Hematol ; 104: 78-86, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27321375

RESUMO

Asulacrine (ASL), a weakly basic and highly lipophilic drug was synthesized in 1980's in cancer research laboratory of Auckland by modifications to the acridine portion of amsacrine on 3-, 4- and 5-substitution patterns. In contrast to its precursor amsacrine (m-AMSA), ASL was effective not only against leukemia and Lewis lung tumor system but also a wide variety of solid tumor. Its metabolic pathway is not same to amsacrine hence different side effects, hepatotoxicity and excretion was observed. Asulacrine is under phase II clinical trials and has showed promising results but its toxicity especially phlebitis is stumbling block in its clinical implementation. This review is an effort to give a possible clue, based on scientifically proven results, to the researchers to solve the mystery of associated toxicity, phlebitis. Review covers the available literature on asulacrine and other acridine derivatives regarding pharmacology, pharmacokinetics, quantitative structure activity relationship and toxicology via electronic search using scientific databases like PubMed and others. To date, all abstracts and full-text articles were discussed and analyzed. The tabulated comparisons and circuitry mechanism of ASL are the added features of the review which give a complete understanding of hidden aspects of possible route cause of associated toxicity, the phlebitis.


Assuntos
Amsacrina/análogos & derivados , Antineoplásicos/efeitos adversos , Neoplasias/tratamento farmacológico , Amsacrina/efeitos adversos , Amsacrina/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Humanos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
11.
Biomed Chromatogr ; 30(12): 1908-1914, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27187844

RESUMO

Asulacrine (ASL), an analogue of amsacrine, has shown higher anti-breast and anti-lung cancer activity. Hereby, a new sensitive and selective liquid chromatography-mass spectrometry (LC/MS) method was developed to determine intracellular asulacrine. The chromatographic separation was performed on an Agilent Zorbax Extend-C18 column (2.1 mm i.d. × 50 mm, 5 µm) using gradient elution with water (2 mmol/L ammonium acetate and 0.1% acetic acid) and acetonitrile as the mobile phase. The detection was achieved with selected ion monitoring mode using electrospray ionization in positive mode with target ions at m/z 465.3 and m/z 326.1 for asulacrine and midazolam, respectively. The standard curve showed a good linearity with the lower limit of quantification of 1 ng/mL, as a result of which, the trace concentration of ASL in cell suspension could be quantified. The intra- and inter-day accuracy ranged from -5.28 to 6.5% and from -6.32 to 1.05%, and the intra- and inter-day precisions were no more than 7.65% and 11.71%, respectively. Additionally, no degradation of asulacrine was observed during stability evaluation. The method was proved to be powerful and practical to determine and compare the intracellular distribution and kinetics of ASL under different formulations in MCF-7 breast cancer cells.


Assuntos
Amsacrina/análogos & derivados , Antineoplásicos/farmacocinética , Neoplasias da Mama/metabolismo , Cromatografia Líquida/métodos , Lipossomos , Espectrometria de Massas/métodos , Amsacrina/farmacocinética , Neoplasias da Mama/patologia , Feminino , Humanos , Células MCF-7 , Reprodutibilidade dos Testes
12.
J Chromatogr A ; 1444: 74-85, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-27040513

RESUMO

Asulacrine (ASL) is a broad-spectrum, antitumor drug whose data are promising for the treatment of breast and lung cancers; however, a high incidence of phlebitis hampered its further development. Phlebitis is associated with generation of reactive species. Asulacrine donates electrons and produces oxidative stress in chemical reactions. It was expected that ASL would actively metabolize to oxidized products through reactive intermediates and produce more products in vivo than reported and thus cause phlebitis. A comprehensive study was planned to investigate in vivo metabolism of ASL, using high-resolution mass spectrometry LC/IT-TOF MS in positive mode. Metabolites were detected by different software by applying annotated detection strategy. The possible metabolites and their product ions were simultaneously detected by segmented data acquisition to get accurate mass values. Segmented data acquisition improved signal-to-noise (S/N) ratio, which was helpful to detect metabolites and their fragments even when present in trace amounts. A total of 21 metabolites were detected in gender-based biological fluids and characterized by comparing their accurate mass values, fragmentation patterns, and relative retention times with that of ASL. Among previously reported glucuronosylation metabolites, some oxidation, hydroxylation, carboxylation, demethylation, hydrogenation, glutamination, and acetylcysteine conjugation were detected for the first time. Twenty metabolites were tentatively identified by using the annotated strategy for data acquisition and post-data mining.


Assuntos
Amsacrina/análogos & derivados , Mineração de Dados , Espectrometria de Massas , Amsacrina/metabolismo , Animais , Bile/química , Feminino , Masculino , Peso Molecular , Ratos , Software , Urina/química
13.
Virology ; 493: 209-16, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27060564

RESUMO

DNA topoisomerases are essential for DNA metabolism and while their role is well studied in prokaryotes and eukaryotes, it is less known for virally-encoded topoisomerases. African swine fever virus (ASFV) is a nucleo-cytoplasmic large DNA virus that infects Ornithodoros ticks and all members of the family Suidae, representing a global threat for pig husbandry with no effective vaccine nor treatment. It was recently demonstrated that ASFV codes for a type II topoisomerase, highlighting a possible target for control of the virus. In this work, the ASFV DNA topoisomerase II was expressed in Saccharomyces cerevisiae and found to efficiently decatenate kDNA and to processively relax supercoiled DNA. Optimal conditions for its activity were determined and its sensitivity to a panel of topoisomerase poisons and inhibitors was evaluated. Overall, our results provide new knowledge on viral topoisomerases and on ASFV, as well as a possible target for the control of this virus.


Assuntos
Vírus da Febre Suína Africana/enzimologia , DNA Topoisomerases Tipo II/genética , Inibidores da Topoisomerase II/farmacologia , Vírus da Febre Suína Africana/genética , Aminocumarinas/farmacologia , Amsacrina/farmacologia , Crithidia fasciculata/genética , Doxorrubicina/farmacologia , Saccharomyces cerevisiae/genética
14.
Drug Des Devel Ther ; 10: 1019-28, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27019595

RESUMO

Amsacrine analog is a novel chemotherapeutic agent that provides potentially broad antitumor activity when compared to traditional amsacrine. However, the major limitation of amsacrine analog is that it is highly lipophilic, making it nonconductive to intravenous administration. The aim of this study was to utilize solid lipid nanoparticles (SLN) to resolve the delivery problem and to investigate the biodistribution of amsacrine analog-loaded SLN. Physicochemical characterizations of SLN, including particle size, zeta potential, entrapment efficiency, and stability, were evaluated. In vitro release behavior was also measured by the dialysis method. In vivo pharmacokinetics and biodistribution behavior of amsacrine analog were investigated and incorporated with a non invasion in vivo imaging system to confirm the localization of SLN. The results showed that amsacrine analog-loaded SLN was 36.7 nm in particle size, 0.37 in polydispersity index, and 34.5±0.047 mV in zeta potential. More than 99% of amsacrine analog was successfully entrapped in the SLN. There were no significant differences in the physicochemical properties after storage at room temperature (25°C) for 1 month. Amsacrine analog-loaded SLN maintained good stability. An in vitro release study showed that amsacrine analog-loaded SLN sustained a release pattern and followed the zero equation. An in vivo pharmacokinetics study showed that amsacrine analog was rapidly distributed from the central compartment to the tissue compartments after intravenous delivery of amsacrine analog-loaded SLN. The biodistribution behavior demonstrated that amsacrine analog mainly accumulated in the lungs. Noninvasion in vivo imaging system images also confirmed that the drug distribution was predominantly localized in the lungs when IR-780-loaded SLN was used.


Assuntos
Amsacrina/análogos & derivados , Amsacrina/farmacocinética , Sistemas de Liberação de Medicamentos , Lipídeos/química , Nanopartículas/administração & dosagem , Nanopartículas/química , Amsacrina/administração & dosagem , Amsacrina/sangue , Animais , Cromatografia Líquida de Alta Pressão , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos ICR , Estrutura Molecular , Tamanho da Partícula , Solubilidade , Propriedades de Superfície , Distribuição Tecidual
15.
Tumori ; 102(2): 124-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27002947

RESUMO

This article highlights the important collaboration between the U.S. NCI in Bethesda, Maryland and the Istituto Tumori in Milan, Italy that had a major impact on the development of curative regimens for breast cancer, Hodgkin's disease and diffuse large B cell lymphoma.In addition to his contribution to developing new therapies, Gianni Bonadonna played an important role in bringing highly focused, disciplined, ethical clinical trials to the European continent.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Doença de Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/tratamento farmacológico , Oncologia/história , Amsacrina/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/história , Bleomicina/administração & dosagem , Neoplasias da Mama/história , Neoplasias da Mama/mortalidade , Ensaios Clínicos como Assunto/história , Comportamento Cooperativo , Ciclofosfamida/administração & dosagem , Ciclofosfamida/história , Doxorrubicina/administração & dosagem , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/história , História do Século XX , História do Século XXI , Doença de Hodgkin/história , Doença de Hodgkin/mortalidade , Humanos , Itália , Tábuas de Vida , Linfoma não Hodgkin/história , Linfoma não Hodgkin/mortalidade , Masculino , Mecloretamina/administração & dosagem , Mecloretamina/história , Metotrexato/administração & dosagem , Metotrexato/história , National Cancer Institute (U.S.) , Prednisona/administração & dosagem , Prednisona/história , Procarbazina/administração & dosagem , Procarbazina/história , Estados Unidos , Vincristina/administração & dosagem , Vincristina/história
16.
Int J Pharm ; 505(1-2): 194-203, 2016 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-27021465

RESUMO

This paper describes a novel method to improve drug retention in liposomes for the poorly water-soluble (lipophilic) model drug asulacrine (ASL). ASL was loaded in the aqueous phase of liposomes and the effects of aging conditions and drug loading levels on drug retention were investigated using an in vitro bio-relevant drug release test established in this study. The status of intra-liposomal drug was investigated using differential scanning calorimetry (DSC) and cryo-transmission electron microscopy (cryo-TEM). Pharmacokinetics and venous tolerance of the formulations were simultaneously studied in rabbits following one-hour intravenous infusion via the ear vein. The presence of glucose during aging was found to be crucial to accelerate drug precipitation and to stabilize the liposomal membrane with high drug loading (8.9% over 4.5% w/w) as a prerequisite. Although no drug crystals were detected, DSC showed a lower phase-transition peak in the glucose-assisted aged ASL-liposomes, indicating interaction of phospholipids with the sugar. Cryo-TEM revealed more 'coffee bean' like drug precipitate in the ASL-liposomes aged in the glucose solution. In rabbits, these liposomes gave rise to a 1.9 times longer half-life than the fresh liposomes, with no venous irritation observed. Inducing and stabilizing drug precipitation in the liposome cores by aging in the presence of sugar provided an easy approach to improve drug retention in liposomes. The study also highlighted the importance of bio-relevance of in vitro release methods to predict in vivo drug release.


Assuntos
Amsacrina/análogos & derivados , Antineoplásicos/administração & dosagem , Glucose/química , Amsacrina/administração & dosagem , Amsacrina/química , Animais , Antineoplásicos/química , Varredura Diferencial de Calorimetria , Precipitação Química , Química Farmacêutica/métodos , Liberação Controlada de Fármacos , Meia-Vida , Infusões Intravenosas , Lipossomos , Microscopia Eletrônica de Transmissão , Transição de Fase , Coelhos , Solubilidade
18.
Nat Chem Biol ; 12(1): 40-5, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26619249

RESUMO

The majority of bacterial proteins are dispensable for growth in the laboratory but nevertheless have important physiological roles. There are no systematic approaches to identify cell-permeable small-molecule inhibitors of these proteins. We demonstrate a strategy to identify such inhibitors that exploits synthetic lethal relationships both for small-molecule discovery and for target identification. Applying this strategy in Staphylococcus aureus, we have identified a compound that inhibits DltB, a component of the teichoic acid D-alanylation machinery that has been implicated in virulence. This D-alanylation inhibitor sensitizes S. aureus to aminoglycosides and cationic peptides and is lethal in combination with a wall teichoic acid inhibitor. We conclude that DltB is a druggable target in the D-alanylation pathway. More broadly, the work described demonstrates a systematic method to identify biologically active inhibitors of major bacterial processes that can be adapted to numerous organisms.


Assuntos
Amsacrina/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos/métodos , Staphylococcus aureus/efeitos dos fármacos , Aminoglicosídeos/farmacologia , Amsacrina/química , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Testes de Sensibilidade Microbiana , Mutação , Bibliotecas de Moléculas Pequenas/farmacologia , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade , Ácidos Teicoicos/metabolismo
19.
J Cancer Res Clin Oncol ; 142(1): 317-24, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26424692

RESUMO

INTRODUCTION: Hematopoietic stem cell transplantation (HCT) is considered a standard treatment for high-risk acute myeloid leukemia (AML) in first or second complete remission (CR). Unfortunately, not all patients achieve complete remission prior to HCT. We sought to establish predictive factors for survival after HCT for refractory AML after FLAMSA-RIC. PATIENTS AND METHODS: We analyzed the outcome of 44 consecutive patients aged between 21 and 65 years transplanted at the University Hospitals of Jena and Leipzig for refractory AML between 2006 and January 2013. Conditioning for HCT was performed with chemotherapy consisting of fludarabine, cytarabine, and amsacrine followed by total body irradiation or busulfan combined with cyclophosphamide. Antithymocyte globulin was given when transplanting from unrelated donors (FLAMSA-RIC). RESULTS: Estimated overall survival (OS) and event-free survival (EFS) at 3 years after a median follow-up of 34 (range 6-71) months were 15 and 12 %, respectively. Causes of death were relapse in 66 %, infection in 11 %, and graft-versus-host disease (GvHD) in 7 % of all patients. Twenty-five from 42 evaluable patients (60 %) achieved CR 4 weeks after HCT, while eight patients had partial remission (PR), and nine patients had stable disease (SD). Another six patients with PR and SD achieved CR (overall CR rate 74 %) from 4 weeks to day 90 after HCT following reduction in immunosuppression. The strongest favorable factors in univariate analysis for OS, EFS, and RI were ≥98 % total donor chimerism 2-4 weeks after HCT and <3 lines of pretreatment prior to HCT. In addition, better OS was detected in patients with <20 % bone marrow blasts alone (32 vs. 5 % at 3 years) and in combination with <3 lines of pretreatment (38 vs. 4 % at 3 years). Only a trend for better EFS and lower RI was observed in patients with limited chronic GvHD. In addition, a lower RI was seen in patients with <5 % blasts 4 weeks after HCT. Multivariate analysis revealed that ≥98 % donor chimerism 2-4 weeks after HCT for OS, EFS, and RI and <3 lines of pretreatment for OS and EFS are the strongest predictors for better outcome. CONCLUSION: FLAMSA-RIC shows long-term survival in refractory AML patients. Factors for favorable outcome are <20 % bone marrow blasts prior to HCT, <3 lines of pretreatment and complete donor chimerism after HCT.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doença Enxerto-Hospedeiro/mortalidade , Transplante de Células-Tronco Hematopoéticas/mortalidade , Leucemia Mieloide Aguda/terapia , Recidiva Local de Neoplasia/terapia , Adulto , Idoso , Amsacrina/administração & dosagem , Terapia Combinada , Citarabina/administração & dosagem , Feminino , Seguimentos , Humanos , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Prognóstico , Indução de Remissão , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Condicionamento Pré-Transplante , Transplante Homólogo , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados , Adulto Jovem
20.
J Control Release ; 203: 161-9, 2015 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25701612

RESUMO

The ultimate aim of this study was to develop asulacrine (ASL)-loaded long-circulating liposomes to prevent phlebitis during intravenous (i.v.) infusion for chemotherapy. Poly(ethylene)glycol (PEG) and poloxamer 188-modified liposomes (ASL-PEGL and ASL-P188L) were developed, and ASL was loaded using a remote loading method facilitated with a low concentration of sulfobutyl ether-ß-cyclodextrin as a drug solubilizer. The liposomes were characterized in terms of morphology, size, release properties and stability. Pharmacokinetics and venous tissue tolerance of the formulations were simultaneously studied in rabbits following one-hour i.v. infusion via the ear vein. The irritancy was assessed using a rat paw-lift/lick model after subplantar injections. High drug loading 9.0% w/w was achieved with no drug leakage found from ASL-PEGL or ASL-P188L suspended in a 5% glucose solution at 30days. However, a rapid release (leakage) from ASL-PEGL was observed when PBS was used as release medium, partially related to the use of cyclodextrin in drug loading. Post-insertion of poloxamer 188 to the liposomes appeared to be able to restore the drug retention possibly by increasing the packing density of phospholipids in the membrane. In rabbits (n=5), ASL-P188L had a prolonged half-life with no drug precipitation or inflammation in the rabbit ear vein in contrast to ASL solution. Following subplantar (footpad) injections in rats ASL solution induced paw-lick/lift responses in all rats whereas ASL-P188L caused no response (n=8). PEGylation showed less benefit possibly due to the drug 'leakage'. In conclusion, drug precipitation in the vein and the drug mild irritancy may both contribute to the occurrence of phlebitis caused by the ASL solution, and could both be prevented by encapsulation of the drug in liposomes. Poloxamer 188 appeared to be able to 'seal' the liposomal membrane and enhance drug retention. The study also highlighted the importance of bio-relevant in vitro release study in formulation screening.


Assuntos
Amsacrina/análogos & derivados , Antineoplásicos/administração & dosagem , Bombas de Infusão/efeitos adversos , Lipossomos/química , Flebite/etiologia , Poloxâmero/química , Polietilenoglicóis/química , Amsacrina/administração & dosagem , Amsacrina/efeitos adversos , Amsacrina/farmacocinética , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Precipitação Química , Injeções/efeitos adversos , Masculino , Flebite/induzido quimicamente , Flebite/prevenção & controle , Coelhos , Ratos Sprague-Dawley
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