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1.
Nat Commun ; 15(1): 4994, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862466

RESUMO

Single-cell transcriptomics and spatially-resolved imaging/sequencing technologies have revolutionized biomedical research. However, they suffer from lack of spatial information and a trade-off of resolution and gene coverage, respectively. We propose DOT, a multi-objective optimization framework for transferring cellular features across these data modalities, thus integrating their complementary information. DOT uses genes beyond those common to the data modalities, exploits the local spatial context, transfers spatial features beyond cell-type information, and infers absolute/relative abundance of cell populations at tissue locations. Thus, DOT bridges single-cell transcriptomics data with both high- and low-resolution spatially-resolved data. Moreover, DOT combines practical aspects related to cell composition, heterogeneity, technical effects, and integration of prior knowledge. Our fast implementation based on the Frank-Wolfe algorithm achieves state-of-the-art or improved performance in localizing cell features in high- and low-resolution spatial data and estimating the expression of unmeasured genes in low-coverage spatial data.


Assuntos
Algoritmos , Análise de Célula Única , Análise de Célula Única/métodos , Humanos , Perfilação da Expressão Gênica/métodos , Transcriptoma , Animais , Biologia Computacional/métodos
2.
Cell Genom ; 3(11): 100439, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-38020967

RESUMO

We designed and synthesized synI, which is ∼21.6% shorter than native chrI, the smallest chromosome in Saccharomyces cerevisiae. SynI was designed for attachment to another synthetic chromosome due to concerns surrounding potential instability and karyotype imbalance and is now attached to synIII, yielding the first synthetic yeast fusion chromosome. Additional fusion chromosomes were constructed to study nuclear function. ChrIII-I and chrIX-III-I fusion chromosomes have twisted structures, which depend on silencing protein Sir3. As a smaller chromosome, chrI also faces special challenges in assuring meiotic crossovers required for efficient homolog disjunction. Centromere deletions into fusion chromosomes revealed opposing effects of core centromeres and pericentromeres in modulating deposition of the crossover-promoting protein Red1. These effects extend over 100 kb and promote disproportionate Red1 enrichment, and thus crossover potential, on small chromosomes like chrI. These findings reveal the power of synthetic genomics to uncover new biology and deconvolute complex biological systems.

3.
Nucleic Acids Res ; 50(8): 4545-4556, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35412621

RESUMO

Successful meiotic recombination, and thus fertility, depends on conserved axis proteins that organize chromosomes into arrays of anchored chromatin loops and provide a protected environment for DNA exchange. Here, we show that the stereotypic chromosomal distribution of axis proteins in Saccharomyces cerevisiae is the additive result of two independent pathways: a cohesin-dependent pathway, which was previously identified and mediates focal enrichment of axis proteins at gene ends, and a parallel cohesin-independent pathway that recruits axis proteins to broad genomic islands with high gene density. These islands exhibit elevated markers of crossover recombination as well as increased nucleosome density, which we show is a direct consequence of the underlying DNA sequence. A predicted PHD domain in the center of the axis factor Hop1 specifically mediates cohesin-independent axis recruitment. Intriguingly, other chromosome organizers, including cohesin, condensin, and topoisomerases, are differentially depleted from the same regions even in non-meiotic cells, indicating that these DNA sequence-defined chromatin islands exert a general influence on the patterning of chromosome structure.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Cromossomos Fúngicos/genética , Cromossomos Fúngicos/metabolismo , Meiose/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
4.
Sci Rep ; 11(1): 13505, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34188098

RESUMO

The age of precision medicine demands powerful computational techniques to handle high-dimensional patient data. We present MultiSurv, a multimodal deep learning method for long-term pan-cancer survival prediction. MultiSurv uses dedicated submodels to establish feature representations of clinical, imaging, and different high-dimensional omics data modalities. A data fusion layer aggregates the multimodal representations, and a prediction submodel generates conditional survival probabilities for follow-up time intervals spanning several decades. MultiSurv is the first non-linear and non-proportional survival prediction method that leverages multimodal data. In addition, MultiSurv can handle missing data, including single values and complete data modalities. MultiSurv was applied to data from 33 different cancer types and yields accurate pan-cancer patient survival curves. A quantitative comparison with previous methods showed that Multisurv achieves the best results according to different time-dependent metrics. We also generated visualizations of the learned multimodal representation of MultiSurv, which revealed insights on cancer characteristics and heterogeneity.


Assuntos
Sobreviventes de Câncer , Bases de Dados Factuais , Aprendizado Profundo , Modelos Biológicos , Neoplasias/mortalidade , Humanos , Valor Preditivo dos Testes , Taxa de Sobrevida
5.
Genetics ; 215(1): 59-73, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32152049

RESUMO

During meiotic prophase, concurrent transcription, recombination, and chromosome synapsis place substantial topological strain on chromosomal DNA, but the role of topoisomerases in this context remains poorly defined. Here, we analyzed the roles of topoisomerases I and II (Top1 and Top2) during meiotic prophase in Saccharomyces cerevisiae We show that both topoisomerases accumulate primarily in promoter-containing intergenic regions of actively transcribing genes, including many meiotic double-strand break (DSB) hotspots. Despite the comparable binding patterns, top1 and top2 mutations have different effects on meiotic recombination. TOP1 disruption delays DSB induction and shortens the window of DSB accumulation by an unknown mechanism. By contrast, temperature-sensitive top2-1 mutants exhibit a marked delay in meiotic chromosome remodeling and elevated DSB signals on synapsed chromosomes. The problems in chromosome remodeling were linked to altered Top2 binding patterns rather than a loss of Top2 catalytic activity, and stemmed from a defect in recruiting the chromosome remodeler Pch2/TRIP13 to synapsed chromosomes. No chromosomal defects were observed in the absence of TOP1 Our results imply independent roles for Top1 and Top2 in modulating meiotic chromosome structure and recombination.


Assuntos
Quebras de DNA de Cadeia Dupla , DNA Topoisomerases Tipo II/metabolismo , DNA Topoisomerases Tipo I/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Cromossomos Fúngicos/genética , Cromossomos Fúngicos/ultraestrutura , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo II/genética , Meiose , Ligação Proteica , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética
6.
Nat Commun ; 10(1): 970, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30814509

RESUMO

Faithful meiotic chromosome inheritance and fertility rely on the stimulation of meiotic crossover recombination by potentially genotoxic DNA double-strand breaks (DSBs). To avoid excessive damage, feedback mechanisms down-regulate DSBs, likely in response to initiation of crossover repair. In Saccharomyces cerevisiae, this regulation requires the removal of the conserved DSB-promoting protein Hop1/HORMAD during chromosome synapsis. Here, we identify privileged end-adjacent regions (EARs) spanning roughly 100 kb near all telomeres that escape DSB down-regulation. These regions retain Hop1 and continue to break in pachynema despite normal synaptonemal complex deposition. Differential retention of Hop1 requires the disassemblase Pch2/TRIP13, which preferentially removes Hop1 from telomere-distant sequences, and is modulated by the histone deacetylase Sir2 and the nucleoporin Nup2. Importantly, the uniform size of EARs among chromosomes contributes to disproportionately high DSB and repair signals on short chromosomes in pachynema, suggesting that EARs partially underlie the curiously high recombination rate of short chromosomes.


Assuntos
Cromossomos Fúngicos/genética , Quebras de DNA de Cadeia Dupla , Meiose/genética , Saccharomyces cerevisiae/genética , Telômero/genética , Pareamento Cromossômico/genética , Cromossomos Fúngicos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Proteínas Nucleares/metabolismo , Recombinação Genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo , Sirtuína 2/metabolismo , Telômero/metabolismo
7.
BMC Genomics ; 20(1): 54, 2019 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30654749

RESUMO

BACKGROUND: Chromatin-immunoprecipitation followed by sequencing (ChIP-seq) is the method of choice for mapping genome-wide binding of chromatin-associated factors. However, broadly applicable methods for between-sample comparisons are lacking. RESULTS: Here, we introduce SNP-ChIP, a method that leverages small-scale intra-species polymorphisms, mainly SNPs, for quantitative spike-in normalization of ChIP-seq results. Sourcing spike-in material from the same species ensures antibody cross-reactivity and physiological coherence, thereby eliminating two central limitations of traditional spike-in approaches. We show that SNP-ChIP is robust to changes in sequencing depth and spike-in proportions, and reliably identifies changes in overall protein levels, irrespective of changes in binding distribution. Application of SNP-ChIP to test cases from budding yeast meiosis allowed discovery of novel regulators of the chromosomal protein Red1 and quantitative analysis of the DNA-damage associated histone modification γ-H2AX. CONCLUSION: SNP-ChIP is fully compatible with the intra-species diversity of humans and most model organisms and thus offers a general method for normalizing ChIP-seq results.


Assuntos
Imunoprecipitação da Cromatina/métodos , Genoma Fúngico , Polimorfismo de Nucleotídeo Único/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Mutação/genética , Ligação Proteica , Proteínas de Saccharomyces cerevisiae/metabolismo , Análise de Sequência de DNA , Coesinas
8.
mSphere ; 1(2)2016.
Artigo em Inglês | MEDLINE | ID: mdl-27303714

RESUMO

Candida glabrata is the second most common Candida species causing disseminated infection, after C. albicans. C. glabrata is intrinsically less susceptible to the widely used azole antifungal drugs and quickly develops secondary resistance. Resistance typically relies on drug efflux with transporters regulated by the transcription factor Pdr1. Gain-of-function (GOF) mutations in PDR1 lead to a hyperactive state and thus efflux transporter upregulation. Our laboratory has characterized a collection of C. glabrata clinical isolates in which azole resistance was found to correlate with increased virulence in vivo. Contributing phenotypes were the evasion of adhesion and phagocytosis by macrophages and an increased adhesion to epithelial cells. These phenotypes were found to be dependent on PDR1 GOF mutation and/or C. glabrata strain background. In the search for the molecular effectors, we found that PDR1 hyperactivity leads to overexpression of specific cell wall adhesins of C. glabrata. Further study revealed that EPA1 regulation, in particular, explained the increase in adherence to epithelial cells. Deleting EPA1 eliminates the increase in adherence in an in vitro model of interaction with epithelial cells. In a murine model of urinary tract infection, PDR1 hyperactivity conferred increased ability to colonize the bladder and kidneys in an EPA1-dependent way. In conclusion, this study establishes a relationship between PDR1 and the regulation of cell wall adhesins, an important virulence attribute of C. glabrata. Furthermore, our data show that PDR1 hyperactivity mediates increased adherence to host epithelial tissues both in vitro and in vivo through upregulation of the adhesin gene EPA1. IMPORTANCE Candida glabrata is an important fungal pathogen in human diseases and is also rapidly acquiring drug resistance. Drug resistance can be mediated by the transcriptional activator PDR1, and this results in the upregulation of multidrug transporters. Intriguingly, this resistance mechanism is associated in C. glabrata with increased virulence in animal models and also with increased adherence to specific host cell types. The C. glabrata adhesin gene EPA1 is a major contributor of virulence and adherence to host cells. Here, we show that EPA1 expression is controlled by PDR1 independently of subtelomeric silencing, a known EPA1 regulation mechanism. Thus, a relationship exists between PDR1, EPA1 expression, and adherence to host cells, which is critical for efficient virulence. Our results demonstrate that acquisition of drug resistance is beneficial for C. glabrata in fungus-host relationships. These findings further highlight the challenges of the therapeutic management of C. glabrata infections in human patients.

9.
Nature ; 530(7591): 485-9, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26886795

RESUMO

Eukaryotic transcription activators stimulate the expression of specific sets of target genes through recruitment of co-activators such as the RNA polymerase II-interacting Mediator complex. Aberrant function of transcription activators has been implicated in several diseases. However, therapeutic targeting efforts have been hampered by a lack of detailed molecular knowledge of the mechanisms of gene activation by disease-associated transcription activators. We previously identified an activator-targeted three-helix bundle KIX domain in the human MED15 Mediator subunit that is structurally conserved in Gal11/Med15 Mediator subunits in fungi. The Gal11/Med15 KIX domain engages pleiotropic drug resistance transcription factor (Pdr1) orthologues, which are key regulators of the multidrug resistance pathway in Saccharomyces cerevisiae and in the clinically important human pathogen Candida glabrata. The prevalence of C. glabrata is rising, partly owing to its low intrinsic susceptibility to azoles, the most widely used antifungal agent. Drug-resistant clinical isolates of C. glabrata most commonly contain point mutations in Pdr1 that render it constitutively active, suggesting that this transcriptional activation pathway represents a linchpin in C. glabrata multidrug resistance. Here we perform sequential biochemical and in vivo high-throughput screens to identify small-molecule inhibitors of the interaction of the C. glabrata Pdr1 activation domain with the C. glabrata Gal11A KIX domain. The lead compound (iKIX1) inhibits Pdr1-dependent gene activation and re-sensitizes drug-resistant C. glabrata to azole antifungals in vitro and in animal models for disseminated and urinary tract C. glabrata infection. Determining the NMR structure of the C. glabrata Gal11A KIX domain provides a detailed understanding of the molecular mechanism of Pdr1 gene activation and multidrug resistance inhibition by iKIX1. We have demonstrated the feasibility of small-molecule targeting of a transcription factor-binding site in Mediator as a novel therapeutic strategy in fungal infectious disease.


Assuntos
Antifúngicos/farmacologia , Candida glabrata/efeitos dos fármacos , Candida glabrata/metabolismo , Farmacorresistência Fúngica/efeitos dos fármacos , Proteínas Fúngicas/metabolismo , Complexo Mediador/metabolismo , Transativadores/metabolismo , Animais , Sítios de Ligação/efeitos dos fármacos , Candida glabrata/genética , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Farmacorresistência Fúngica Múltipla/efeitos dos fármacos , Fluconazol/farmacologia , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Hidrazinas/farmacocinética , Hidrazinas/farmacologia , Cetoconazol/farmacologia , Complexo Mediador/química , Camundongos , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Tioureia/análogos & derivados , Tioureia/farmacocinética , Tioureia/farmacologia , Transativadores/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
10.
FEMS Yeast Res ; 15(4): fov025, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25979690

RESUMO

Among existing fungal pathogens, Candida glabrata is outstanding in its capacity to rapidly develop resistance to currently used antifungal agents. Resistance to the class of azoles, which are still widely used agents, varies in proportion (from 5 to 20%) depending on geographical area. Moreover, resistance to the class of echinocandins, which was introduced in the late 1990s, is rising in several institutions. The recent emergence of isolates with acquired resistance to both classes of agents is a major concern since alternative therapeutic options are scarce. Although considered less pathogenic than C. albicans, C. glabrata has still evolved specific virulence traits enabling its survival and propagation in colonized and infected hosts. Development of drug resistance is usually associated with fitness costs, and this notion is documented across several microbial species. Interestingly, azole resistance in C. glabrata has revealed the opposite. Experimental models of infection showed enhanced virulence of azole-resistant isolates. Moreover, azole resistance could be associated with specific changes in adherence properties to epithelial cells or innate immunity cells (macrophages), both of which contribute to virulence changes. Here we will summarize the current knowledge on C. glabrata drug resistance and also discuss the consequences of drug resistance acquisition on the balance between C. glabrata and its hosts.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida glabrata/efeitos dos fármacos , Candida glabrata/patogenicidade , Farmacorresistência Fúngica , Equinocandinas/farmacologia , Animais , Candidíase/microbiologia , Candidíase/patologia , Modelos Animais de Doenças , Humanos , Virulência
11.
Antimicrob Agents Chemother ; 57(7): 3182-93, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23629718

RESUMO

Antifungal resistance of Candida species is a clinical problem in the management of diseases caused by these pathogens. In this study we identified from a collection of 423 clinical samples taken from Tunisian hospitals two clinical Candida species (Candida albicans JEY355 and Candida tropicalis JEY162) with decreased susceptibility to azoles and polyenes. For JEY355, the fluconazole (FLC) MIC was 8 µg/ml. Azole resistance in C. albicans JEY355 was mainly caused by overexpression of a multidrug efflux pump of the major facilitator superfamily, Mdr1. The regulator of Mdr1, MRR1, contained a yet-unknown gain-of-function mutation (V877F) causing MDR1 overexpression. The C. tropicalis JEY162 isolate demonstrated cross-resistance between FLC (MIC > 128 µg/ml), voriconazole (MIC > 16 µg/ml), and amphotericin B (MIC > 32 µg/ml). Sterol analysis using gas chromatography-mass spectrometry revealed that ergosterol was undetectable in JEY162 and that it accumulated 14α-methyl fecosterol, thus indicating a perturbation in the function of at least two main ergosterol biosynthesis proteins (Erg11 and Erg3). Sequence analyses of C. tropicalis ERG11 (CtERG11) and CtERG3 from JEY162 revealed a deletion of 132 nucleotides and a single amino acid substitution (S258F), respectively. These two alleles were demonstrated to be nonfunctional and thus are consistent with previous studies showing that ERG11 mutants can only survive in combination with other ERG3 mutations. CtERG3 and CtERG11 wild-type alleles were replaced by the defective genes in a wild-type C. tropicalis strain, resulting in a drug resistance phenotype identical to that of JEY162. This genetic evidence demonstrated that CtERG3 and CtERG11 mutations participated in drug resistance. During reconstitution of the drug resistance in C. tropicalis, a strain was obtained harboring only defective Cterg11 allele and containing as a major sterol the toxic metabolite 14α-methyl-ergosta-8,24(28)-dien-3α,6ß-diol, suggesting that ERG3 was still functional. This strain therefore challenged the current belief that ERG11 mutations cannot be viable unless accompanied by compensatory mutations. In conclusion, this study, in addition to identifying a novel MRR1 mutation in C. albicans, constitutes the first report on a clinical C. tropicalis with defective activity of sterol 14α-demethylase and sterol Δ(5,6)-desaturase leading to azole-polyene cross-resistance.


Assuntos
Candida albicans/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Azóis/farmacologia , Sequência de Bases , Candida albicans/genética , Candida albicans/isolamento & purificação , Candida glabrata/genética , Candida glabrata/isolamento & purificação , Candida tropicalis/isolamento & purificação , Candidíase/tratamento farmacológico , Sistema Enzimático do Citocromo P-450/metabolismo , Ergosterol/biossíntese , Ergosterol/genética , Fluconazol/farmacologia , Proteínas Fúngicas/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Mutação , Polienos/farmacologia , Pirimidinas/farmacologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Análise de Sequência de DNA , Triazóis/farmacologia , Tunísia , Voriconazol
12.
Molecules ; 17(4): 3834-43, 2012 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-22456543

RESUMO

Three aminodi(hetero)arylamines were prepared via a palladium-catalyzed C-N Buchwald-Hartwig coupling of methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate with different bromonitrobenzenes, followed by reduction of the nitro groups of the coupling products to the corresponding amino compounds. The aminodi(hetero)arylamines thus obtained were evaluated for their growth inhibitory effect on four human tumor cell lines MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), NCI-H460 (non-small cell lung cancer) and HepG(2) (hepatocellular carcinoma). The toxicity to non-tumor cells was also evaluated using a porcine liver primary cell culture (PLP1), established by us. The aminodi(hetero)arylamine with the NH(2) group in the ortho position and an OMe group in the para position to the NH of the di(hetero)arylamine, is the most promising compound giving the lowest GI(50) values (1.30-1.63 µM) in all the tested human tumor cell lines, presenting no toxicity to PLP1 at those concentrations. The effect of this compound on the cell cycle and induction of apoptosis was analyzed in the NCI-H460 cell line. It was observed that it altered the cell cycle profile causing a decrease in the percentage of cells in the G0/G1 phase and an increase of the apoptosis levels.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Tienopiridinas/síntese química , Tienopiridinas/farmacologia , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Humanos , Tienopiridinas/toxicidade
13.
Nanoscale Res Lett ; 6(1): 482, 2011 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-21812989

RESUMO

A potential antitumoral fluorescent indole derivative, methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate, was evaluated for the in vitro cell growth inhibition on three human tumor cell lines, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), and NCI-H460 (non-small cell lung cancer), after a continuous exposure of 48 h, exhibiting very low GI50 values for all the cell lines tested (0.25 to 0.33 µM). This compound was encapsulated in different nanosized liposome formulations, containing egg lecithin (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylglycerol (DPPG), DSPC, cholesterol, dihexadecyl phosphate, and DSPE-PEG. Dynamic light scattering measurements showed that nanoliposomes with the encapsulated compound are generally monodisperse and with hydrodynamic diameters lower than 120 nm, good stability and zeta potential values lower than -18 mV. Dialysis experiments allowed to monitor compound diffusion through the lipid membrane, from DPPC/DPPG donor liposomes to NBD-labelled lipid/DPPC/DPPG acceptor liposomes.

14.
Eur J Med Chem ; 46(1): 236-40, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21138784

RESUMO

The methyl 3-amino-6-bromothieno[3,2-b]pyridine-2-carboxylate, recently reported by some of us, was reacted in Sonogashira couplings with several (hetero)arylacetylenes. The growth inhibitory activity of the novel methyl 3-amino-6-[(hetero)arylethynyl]thieno[3,2-b]pyridine-2-carboxylates obtained was evaluated on three human tumor cell lines (MCF-7, NCI-H460, A375-C5). The para-methoxyphenyl and the ortho- and para-aminophenyl derivatives were the most promising compounds, and their effects were further studied regarding alterations in the normal cell cycle distribution and induction of apoptosis in the NCI-H460 cell line. All three compounds altered cell cycle distribution and the ortho-aminophenyl derivative was further shown to induce apoptosis in the same cell line.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Antineoplásicos/síntese química , Ácidos Carboxílicos/síntese química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Relação Estrutura-Atividade
15.
Eur J Med Chem ; 45(12): 5732-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20934235

RESUMO

Several novel 6-[(hetero)arylamino]thieno[3,2-b]pyridines were prepared by palladium-catalyzed C-N Buchwald-Hartwig coupling of the methyl 3-amino-6-bromothieno[3,2-b]pyridine-2-carboxylate with aryl and heteroarylamines, using different reaction conditions. The antitumoral activity of the di(hetero)arylamines obtained was evaluated against three representative human tumor cell lines, namely breast adenocarcinoma (MCF-7), melanoma (A375-C5), and non-small cell lung cancer (NCI-H460) and some structure-activity relationships were established within each series. The most promising compounds were shown to be a benzothiazole derivative with GI50 3.5-6.9 µM followed by an indole derivative with GI50 13-21 µM.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Piridinas/síntese química , Piridinas/farmacologia , Antineoplásicos/química , Catálise , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Paládio/química , Piridinas/química , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
16.
Eur J Med Chem ; 45(12): 5628-34, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20926160

RESUMO

A wide variety of new bi(hetero)aryl derivatives of the thieno[3,2-b]pyridine skeleton was obtained in high to excellent yields (65-91%) by Suzuki-Miyaura cross-coupling of the methyl 3-amino-6-bromothieno[3,2-b]pyridine-2-carboxylate, recently reported by us, with aryl or heteroaryl pinacolboranes or potassium trifluoroborates. The coupling products obtained were evaluated for their growth inhibitory effect on three human tumor cell lines, representing different tumor models, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma) and NCI-H460 (non-small cell lung cancer). Some of the compounds showed an interesting activity against the tested cell lines, with GI50 values in the µM range, and it was possible to establish some structure-activity relationships (SARs). Several compounds presented GI50 values below 15 µM, particularly a bithiophene and an o-aniline thienopyridine derivative. The first presented selectivity for MCF-7 and NCI-H460 cell lines, with very low GI50 values (0.7-1.0 µM), while the latter was active against the three cell lines tested in this study, also presenting very low GI50 values (2.5-4.2 µM). The effect of these two compounds on cell cycle progression was analyzed in the NCI-H460 cell line. Results showed that both compounds interfered with the normal cell cycle distribution.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Piridinas/síntese química , Piridinas/farmacologia , Antineoplásicos/química , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Piridinas/química , Estereoisomerismo , Relação Estrutura-Atividade
17.
J Agric Food Chem ; 58(17): 9529-36, 2010 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-20707344

RESUMO

Lycopersicon esculentum (tomato) fruit is a widely studied matrix. However, only few works focus their attention on its seeds, which constitute a major byproduct of the tomato processing industry. In this study the antimicrobial potential of ten different tomato seed extracts from "Bull's heart" and "Cherry" varieties were analyzed against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Enterococcus faecalis and Bacillus cereus) and Gram-negative (Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium) bacteria and fungi (Candida albicans, Aspergillus fumigatus and Trichophyton rubrum). Regarding antibacterial capacity, the different extracts were revealed to be active only against Gram-positive bacteria, E. faecalis being the most susceptible one (MIC: 2.5-10 mg/mL). Concerning antifungal activity, "Bull's heart" extracts were the most active. In a general way C. albicans was the most susceptible species (MIC: 5-10 mg/mL). The chemical composition of the extracts was also pursued, concerning organic acids, phenolics and fatty acids, in order to establish a possible relationship with the observed antimicrobial effect.


Assuntos
Anti-Infecciosos/farmacologia , Sementes/química , Solanum lycopersicum/embriologia , Anti-Infecciosos/química , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Espectrofotometria Ultravioleta
18.
Eur J Med Chem ; 44(5): 1893-9, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19070942

RESUMO

Several novel 3-(aryl)benzothieno[2,3-c]pyran-1-ones (tricyclic lactones) were prepared either by a tandem one-pot Sonogashira coupling and intramolecular cyclization, reacting the 3-bromobenzo[b]thiophene-2-carboxylic acid with arylacetylenes, or by Sonogashira coupling of the methyl 3-bromobenzo[b]thiophene-2-carboxylate or the methyl 3-bromo-6-methoxybenzo[b]thiophene-2-carboxylate with arylacetylenes followed by an electrophilic intramolecular cyclization using iodine or TFA in two separate steps. The Sonogashira products and the tricyclic lactones obtained were evaluated for their capacity to inhibit the in vitro growth of three human tumor cell lines, MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer). Most of the compounds showed a high growth inhibitory effect on all the tested cell lines, with GI(50) values in the muM range. A structure-activity relationship was established for the Sonogashira products and for the tricyclic lactones, namely related to the presence and position of substituents (OMe and/or F) in the benzothiophene moiety or in the phenyl ring.


Assuntos
Antineoplásicos/síntese química , Piranos/síntese química , Antineoplásicos/farmacologia , Ciclização , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Piranos/farmacologia , Relação Estrutura-Atividade , Tiofenos
19.
Bioorg Med Chem ; 16(17): 8172-7, 2008 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18678498

RESUMO

The antifungal activity of several di(hetero)arylamine derivatives of the benzo[b]thiophene system was evaluated against clinically relevant Candida, Aspergillus, and dermatophyte species by a broth macrodilution test based on CLSI (formerly NCCLS) guidelines. The most active compound showed a broad spectrum of activity (against all tested fungal strains, including fluconazole-resistant fungi), with particularly low MICs for dermatophytes. Results from the inhibition of the dimorphic transition in Candida albicans and flow cytometry studies further confirmed their biological activity. With this study it was possible to establish some structure-activity relationships (SARs). The hydroxy groups proved to be essential for the activity in the aryl derivatives. Furthermore, the spectrum of activity in the pyridine derivatives was broadened by the absence of the ester group on position 2 of the benzo[b]thiophene system.


Assuntos
Aminas/síntese química , Aminas/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Tiofenos/química , Aminas/química , Antifúngicos/química , Arthrodermataceae/efeitos dos fármacos , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Relação Dose-Resposta a Droga , Citometria de Fluxo/métodos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade
20.
Bioorg Med Chem Lett ; 16(9): 2492-5, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16480875

RESUMO

The mechanism of action of the antifungal agent 3-(4-bromophenyl)-5-acyloxymethyl-2,5-dihydrofuran-2-one against Candida albicans was investigated by flow cytometry, using propidium iodide, DiBAC4(3), and FUN-1 as the fluorescent dyes. A related but less active agent, together with amphotericin B and fluconazole, was tested in parallel for comparison of the results. The incrustoporine derivative was found to have a potent fungicidal activity on C. albicans, resulting in damage of cell membrane.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Citometria de Fluxo/métodos , Furanos/farmacologia , Antifúngicos/química , Furanos/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
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