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1.
Thyroid ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38757633

RESUMO

Background: For patients with thyroid cancer, distant metastasis is a significant predictor of poor outcome. Since distant metastasis occur in less than 10% of patients with differentiated thyroid cancer, correlates of survival in this vulnerable patient population remain understudied. This study aimed to identify prognostic groups among patients with differentiated thyroid cancer and distant metastases; and to determine the role of, and interactions between, patient and tumor characteristics in determining survival. Methods: We identified adult patients diagnosed with differentiated thyroid cancer with distant metastases from the U.S. SEER-17 cancer registry (2010-2019). Analyses were performed using Cox proportional hazards regression, survival trees, and random survival forest. Relative importance of patient and tumor factors important for disease-specific and overall survival was assessed based on the random survival forest analyses. Results: Cohort consisted of 2,411 patients with differentiated thyroid cancer with distant metastases followed for a median of 62 months. Most common histopathologic subtype (86.0%) was papillary thyroid cancer, and the most common sites of distant metastasis were the lungs (33.7%) and bone (18.9%). Cox proportional hazards model illustrated significant associations between survival and: patient age (P<0.001), tumor size (P<0.01), and site of distant metastasis (P<0.05). Survival tree analyses identified three distinct prognostic groups based on disease-specific survival (DSS) (5-year survival of the prognostic groups was 92%, 64%, and 41%; P<0.001) and four distinct prognostic groups based on overall survival (OS) (5-year survival of the prognostic groups was 96%, 84%, 57%, and 31%; P<0.001). The first split in the survival trees for DSS and OS was by age at diagnosis (<57 years vs >58 years) with subsequent splits based on presence/absence of lung metastases, tumor size (<4 cm vs >4 cm), and patient age. A total of 558 patients (23.1%) died from thyroid cancer, and 757 patients (31.4%) died from all causes during the study period. Conclusions: This study identifies distinct prognostic groups for patients with differentiated thyroid cancer with distant metastases and highlights the importance of patient age, lung metastases, and tumor size to determining both disease-specific and overall survival. These findings inform risk stratification and treatment decision-making in this understudied patient population.

2.
Cancer Med ; 12(8): 9945-9955, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36808717

RESUMO

BACKGROUND: Only a small proportion of patients who qualify for clinical genetic testing for cancer susceptibility get testing. Many patient-level barriers contribute to low uptake. In this study, we examined self-reported patient barriers and motivators for cancer genetic testing. METHODS: A survey comprised of both new and existing measures related to barriers and motivators to genetic testing was emailed to patients with a diagnosis of cancer at a large academic medical center. Patients who self-reported receiving a genetic test were included in these analyses (n = 376). Responses about emotions following testing as well as barriers and motivators prior to getting testing were examined. Group differences in barriers and motivators by patient demographic characteristics were examined. RESULTS: Being assigned female at birth was associated with increased emotional, insurance, and family concerns as well as increased health benefits compared to patients assigned male at birth. Younger respondents had significantly higher emotional and family concerns compared to older respondents. Recently diagnosed respondents expressed fewer concerns about insurance implications and emotional concerns. Those with a BRCA-related cancer had higher scores on social and interpersonal concerns scale than those with other cancers. Participants with higher depression scores indicated increased emotional, social and interpersonal, and family concerns. CONCLUSIONS: Self-reported depression emerged as the most consistent factor influencing report of barriers to genetic testing. By incorporating mental health resources into clinical practice, oncologists may better identify those patients who might need more assistance following through with a referral for genetic testing and the response afterwards.


Assuntos
Testes Genéticos , Neoplasias , Recém-Nascido , Humanos , Masculino , Feminino , Saúde Mental , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Neoplasias/genética
3.
Adv Exp Med Biol ; 1414: 1-26, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35708844

RESUMO

Three human nucleases, SNM1A, SNM1B/Apollo, and SNM1C/Artemis, belong to the SNM1 gene family. These nucleases are involved in various cellular functions, including homologous recombination, nonhomologous end-joining, cell cycle regulation, and telomere maintenance. These three proteins share a similar catalytic domain, which is characterized as a fused metallo-ß-lactamase and a CPSF-Artemis-SNM1-PSO2 domain. SNM1A and SNM1B/Apollo are exonucleases, whereas SNM1C/Artemis is an endonuclease. This review contains a summary of recent research on SNM1's cellular and biochemical functions, as well as structural biology studies. In addition, protein structure prediction by the artificial intelligence program AlphaFold provides a different view of the proteins' non-catalytic domain features, which may be used in combination with current results from X-ray crystallography and cryo-EM to understand their mechanism more clearly.


Assuntos
Enzimas Reparadoras do DNA , Reparo do DNA , Humanos , Inteligência Artificial , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , Exodesoxirribonucleases/genética , Exodesoxirribonucleases/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Ciclo Celular/metabolismo
4.
Breast Cancer Res Treat ; 197(2): 397-404, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36371776

RESUMO

PURPOSE: At least 5 years of adjuvant endocrine therapy (ET) is recommended for patients with hormone receptor-positive invasive breast cancer to reduce cancer recurrence risk. Up to half of patients prematurely discontinue ET, often due to musculoskeletal pain. Nociplastic pain is abnormal central nervous system pain processing without evidence of tissue or neuronal damage. This study aimed to evaluate the relationship between baseline nociplastic pain and ET discontinuation. METHODS: This was a retrospective, single center, cohort study. Included patients were female, had stage 0-III invasive breast cancer, did not receive neoadjuvant therapy, and completed quality of life questionnaires prior to breast surgery, including Fibromyalgia Survey for nociplastic pain. Clinical data including duration of ET were abstracted from the medical record. Patient characteristics were analyzed with t-tests and Chi-squared tests, as appropriate. Univariate and multivariable regressions were performed with Cox proportional hazard models. RESULTS: Six hundred eighty-one patients diagnosed between 2012 and 2019 met inclusion criteria; 480 initiated ET and were included in the analysis. Of these 480 patients, 203 (42.3%) prematurely discontinued initial ET therapy. On univariate analysis, tamoxifen use (hazard ratio [HR] 0.70, p = 0.021) and premenopausal status (HR 0.73, p = 0.04) were inversely associated with ET discontinuation, while Fibromyalgia Score was positively associated (HR 1.04, p = 0.043). On multivariable analysis, baseline Fibromyalgia Score remained associated with ET discontinuation. CONCLUSION: Nociplastic pain present prior to surgery was associated with premature ET discontinuation. Fibromyalgia Score screening may be useful for evaluating ET discontinuation risk. Treatments targeting nociplastic pain may be more effective for treating ET-emergent pain.


Assuntos
Neoplasias da Mama , Fibromialgia , Dor Musculoesquelética , Humanos , Feminino , Masculino , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/induzido quimicamente , Estudos Retrospectivos , Estudos de Coortes , Fibromialgia/induzido quimicamente , Fibromialgia/complicações , Fibromialgia/tratamento farmacológico , Qualidade de Vida , Recidiva Local de Neoplasia/tratamento farmacológico , Dor Musculoesquelética/induzido quimicamente , Quimioterapia Adjuvante/efeitos adversos , Inibidores da Aromatase/efeitos adversos , Antineoplásicos Hormonais/efeitos adversos
5.
J Vis Exp ; (178)2021 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-34958078

RESUMO

Full-length huntingtin (FL HTT) is a large (aa 1-3,144), ubiquitously expressed, polyglutamine (polyQ)-containing protein with a mass of approximately 350 kDa. While the cellular function of FL HTT is not entirely understood, a mutant expansion of the polyQ tract above ~36 repeats is associated with Huntington's disease (HD), with the polyQ length correlating roughly with the age of onset. To better understand the effect of structure on the function of mutant HTT (mHTT), large quantities of the protein are required. Submilligram production of FL HTT in mammalian cells was achieved using doxycycline-inducible stable cell line expression. However, protein production from stable cell lines has limitations that can be overcome with transient transfection methods. This paper presents a robust method for low-milligram quantity production of FL HTT and its variants from codon-optimized plasmids by transient transfection using polyethylenimine (PEI). The method is scalable (>10 mg) and consistently yields 1-2 mg/L of cell culture of highly purified FL HTT. Consistent with previous reports, the purified solution state of FL HTT was found to be highly dynamic; the protein has a propensity to form dimers and high-order oligomers. A key to slowing oligomer formation is working quickly to isolate the monomeric fractions from the dimeric and high-order oligomeric fractions during size exclusion chromatography. Size exclusion chromatography with multiangle light scattering (SEC-MALS) was used to analyze the dimer and higher-order oligomeric content of purified HTT. No correlation was observed between FL HTT polyQ length (Q23, Q48, and Q73) and oligomer content. The exon1-deleted construct (aa 91-3,144) showed comparable oligomerization propensity to FL HTT (aa 1-3,144). Production, purification, and characterization methods by SEC/MALS-refractive index (RI), sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), western blot, Native PAGE, and Blue Native PAGE are described herein.


Assuntos
Doença de Huntington , Animais , Western Blotting , Linhagem Celular , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Mamíferos/metabolismo , Mutação , Transfecção
6.
J Biol Chem ; 295(35): 12368-12377, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32576658

RESUMO

The endonuclease Artemis is responsible for opening DNA hairpins during V(D)J recombination and for processing a subset of pathological DNA double-strand breaks. Artemis is an attractive target for the development of therapeutics to manage various B cell and T cell tumors, because failure to open DNA hairpins and accumulation of chromosomal breaks may reduce the proliferation and viability of pre-T and pre-B cell derivatives. However, structure-based drug discovery of specific Artemis inhibitors has been hampered by a lack of crystal structures. Here, we report the structure of the catalytic domain of recombinant human Artemis. The catalytic domain displayed a polypeptide fold similar overall to those of other members in the DNA cross-link repair gene SNM1 family and in mRNA 3'-end-processing endonuclease CPSF-73, containing metallo-ß-lactamase and ß-CASP domains and a cluster of conserved histidine and aspartate residues capable of binding two metal atoms in the catalytic site. As in SNM1A, only one zinc ion was located in the Artemis active site. However, Artemis displayed several unique features. Unlike in other members of this enzyme class, a second zinc ion was present in the ß-CASP domain that leads to structural reorientation of the putative DNA-binding surface and extends the substrate-binding pocket to a new pocket, pocket III. Moreover, the substrate-binding surface exhibited a dominant and extensive positive charge distribution compared with that in the structures of SNM1A and SNM1B, presumably because of the structurally distinct DNA substrate of Artemis. The structural features identified here may provide opportunities for designing selective Artemis inhibitors.


Assuntos
Endonucleases/química , Dobramento de Proteína , Zinco/química , Animais , Domínio Catalítico , Proteínas de Ligação a DNA , Endonucleases/genética , Humanos , Células Sf9 , Spodoptera , Relação Estrutura-Atividade
7.
J Microbiol Methods ; 157: 93-99, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30629964

RESUMO

With increasing antibiotic resistance observed amongst clinical isolates of Neisseria gonorrhoeae, the second most prevalent sexually transmitted bacterial disease in the United States, there is still a need for antimicrobial susceptibility testing (AST). The current method recommended by the Clinical and Laboratory Standards Institute is agar dilution. In this study, we show that a commercially available version of Fastidious Broth is capable of supporting N. gonorrhoeae in the evaluation of minimum inhibitory concentrations of 4 antibiotics (ceftriaxone, azithromycin, ciprofloxacin, and tetracycline), when comparing the agar dilution (AD) versus microbroth dilution (MBD) method and the susceptibilities obtained for 32 N. gonorrhoeae isolates. Herein, 3 out of the 4 antibiotics tested showed 94% or greater essential agreement (EA) and 91% or greater categorical agreement (CA) respectively, when comparing the MBD versus AD methods.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/fisiologia , Gonorreia/tratamento farmacológico , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/crescimento & desenvolvimento , Azitromicina/farmacologia , Ceftriaxona/farmacologia , Ciprofloxacina/farmacologia , Contagem de Colônia Microbiana/métodos , Meios de Cultura/química , Humanos , Testes de Sensibilidade Microbiana/métodos , Neisseria gonorrhoeae/isolamento & purificação , Tetraciclina/farmacologia
8.
J Med Chem ; 59(18): 8473-94, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27559615

RESUMO

We previously disclosed the discovery of rationally designed N-((1-(4-(propylsulfonyl)piperazin-1-yl)cycloalkyl)methyl)benzamide inhibitors of glycine transporter-1 (GlyT-1), represented by analogues 10 and 11. We describe herein further structure-activity relationship exploration of this series via an optimization strategy that primarily focused on the sulfonamide and benzamide appendages of the scaffold. These efforts led to the identification of advanced leads possessing a desirable balance of excellent in vitro GlyT-1 potency and selectivity, favorable ADME and in vitro pharmacological profiles, and suitable pharmacokinetic and safety characteristics. Representative analogue (+)-67 exhibited robust in vivo activity in the cerebral spinal fluid glycine biomarker model in both rodents and nonhuman primates. Furthermore, rodent microdialysis experiments also demonstrated that oral administration of (+)-67 significantly elevated extracellular glycine levels within the medial prefrontal cortex (mPFC).


Assuntos
Benzamidas/química , Benzamidas/farmacologia , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Animais , Benzamidas/síntese química , Benzamidas/farmacocinética , Glicina/líquido cefalorraquidiano , Glicina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Macaca fascicularis , Masculino , Metilação , Piperazinas/síntese química , Piperazinas/química , Piperazinas/farmacocinética , Piperazinas/farmacologia , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
9.
Chem Biol Drug Des ; 87(5): 794-805, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26685080

RESUMO

Aquaporins (AQPs) are a family of membrane proteins that function as channels facilitating water transport in response to osmotic gradients. These play critical roles in several normal physiological and pathological states and are targets for drug discovery. Selective inhibition of the AQP1 water channel may provide a new approach for the treatment of several disorders including ocular hypertension/glaucoma, congestive heart failure, brain swelling associated with a stroke, corneal and macular edema, pulmonary edema, and otic disorders such as hearing loss and vertigo. We developed a high-throughput assay to screen a library of compounds as potential AQP1 modulators by monitoring the fluorescence dequenching of entrapped calcein in a confluent layer of AQP1-overexpressing CHO cells that were exposed to a hypotonic shock. Promising candidates were tested in a Xenopus oocyte-swelling assay, which confirmed the identification of two lead classes of compounds belonging to aromatic sulfonamides and dihydrobenzofurans with IC50 s in the low micromolar range. These selected compounds directly inhibited water transport in AQP1-enriched stripped erythrocyte ghosts and in proteoliposomes reconstituted with purified AQP1. Validation of these lead compounds, by the three independent assays, establishes a set of attractive AQP1 blockers for developing novel, small-molecule functional modulators of human AQP1.


Assuntos
Aquaporina 1/antagonistas & inibidores , Animais , Células CHO , Cricetinae , Cricetulus , Humanos
10.
Biomol Detect Quantif ; 4: 1-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27077032

RESUMO

The successful discovery and subsequent development of small molecule inhibitors of drug targets relies on the establishment of robust, cost-effective, quantitative, and physiologically relevant in vitro assays that can support prolonged screening and optimization campaigns. The current study illustrates the process of developing and validating an enzymatic assay for the discovery of small molecule inhibitors using alkaline phosphatase from bovine intestine as model target. The assay development workflow includes an initial phase of optimization of assay materials, reagents, and conditions, continues with a process of miniaturization and automation, and concludes with validation by quantitative measurement of assay performance and signal variability. The assay is further evaluated for dose-response and mechanism-of-action studies required to support structure-activity-relationship studies. Emphasis is placed on the most critical aspects of assay optimization and other relevant considerations, including the technology, assay materials, buffer constituents, reaction conditions, liquid handling equipment, analytical instrumentation, and quantitative assessments. Examples of bottlenecks encountered during assay development and strategies to address them are provided.

11.
J Nat Prod ; 76(9): 1523-7, 2013 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-24050204

RESUMO

Three new compounds named leporizines A-C have been isolated from an Aspergillus sp. strain. Their structures were elucidated by analysis of 1D and 2D NMR spectra. Leporizines A and B were isolated during dereplication of hits from a high-throughput screening campaign for correctors of the cystic fibrosis transmembrane conductance regulator (CFTR), and leporizine C was isolated while preparing additional material for characterization of leporizines A and B. CFTR activity observed for leporizines A and B was highly correlated with cell toxicity and was determined to be a nonspecific effect. Leporizine C was not cytotoxic to cells and did not elicit a response in the CFTR assays. To the best of our knowledge, leporizines A-C represent the first examples of this unusual epithiodiketopiperazine skeleton.


Assuntos
Antineoplásicos/isolamento & purificação , Aspergillus/química , Dicetopiperazinas/isolamento & purificação , Antineoplásicos/química , Antineoplásicos/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/efeitos dos fármacos , Dicetopiperazinas/química , Dicetopiperazinas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2 , Humanos , Estrutura Molecular , Montana , Mutação , Ressonância Magnética Nuclear Biomolecular , Mucosa Respiratória
12.
J Biomol Screen ; 18(1): 75-84, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22983163

RESUMO

Human interleukin 17 (IL-17) is a proinflammatory cytokine derived mainly from activated T cells. Extensive evidence points to a significant role of IL-17 in many autoimmune and infectious diseases, as well as tumorigenesis and transplant rejection, and suggests that targeting IL-17 could be a promising therapeutic strategy. Robust cell-based assays would thus be essential for lead identification and the optimization of therapeutic candidates. Herein, we report a well-characterized two-step assay, consisting of (a) in vitro activation and stimulation of CD4(+) T lymphocytes by a defined complex of antibodies and cytokines, leading to T helper 17 (Th17) cell differentiation and IL-17 production, and (b) IL-17 quantification in cell supernatants using a homogeneous time-resolved fluorescence (HTRF) assay. The system was optimized for and shown to be reliable in high-throughput compatible 96- and 384-well plate formats. The assay is robust (Z' > 0.5) and simple to perform, yields a stable response, and allows for sufficient discrimination of positive (IL-17-producing cells) and negative controls (uninduced cells). The assay was validated by performing dose-response testing of rapamycin and cyclosporine A, which had previously been reported to inhibit IL-17, and determining, for the first time, their in vitro potencies (IC(50)s of 80 ± 23 pM and 223 ± 52 nM, respectively). Also, IKK 16, a selective small-molecule inhibitor of IκB kinase, was found to inhibit IL-17 production, with an IC(50) of 315 ± 79 nM.


Assuntos
Linfócitos T CD4-Positivos/efeitos dos fármacos , Ensaios de Triagem em Larga Escala/métodos , Interleucina-17/antagonistas & inibidores , Células Th17/efeitos dos fármacos , Adulto , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Ciclosporina/farmacologia , Dimetil Sulfóxido/farmacologia , Humanos , Interleucina-17/metabolismo , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Reprodutibilidade dos Testes , Sirolimo/farmacologia , Solventes/farmacologia , Espectrometria de Fluorescência , Células Th17/metabolismo
14.
Bioorg Med Chem Lett ; 20(10): 3017-20, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20427184

RESUMO

An indazole based series of glucocorticoid receptor agonists is reported. The SAR exploration of this scaffold yielded compounds with nanomolar affinity for the glucocorticoid receptor with indications of selectivity for the preferred transrepression mechanism; in vivo efficacy was observed in the mouse LPS induced TNFalpha model for compound 28.


Assuntos
Anti-Inflamatórios/química , Indazóis/química , Receptores de Glucocorticoides/agonistas , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacologia , Indazóis/síntese química , Indazóis/farmacologia , Camundongos , Receptores de Glucocorticoides/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
15.
J Nat Prod ; 72(2): 276-9, 2009 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-19191549

RESUMO

Three new antibiotics, neopyrrolomycins B (1), C (2), and D (3), with potent activity against Gram-positive pathogens were discovered. They exhibited MIC values < 1 microg/mL versus a number of resistant strains. The compounds were obtained from the ethyl acetate extracts of a Streptomyces sp. after purification by column chromatography and RP-HPLC. Their structures were elucidated using X-ray crystallography (1) and NMR spectroscopy (2 and 3).


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Streptomyces/química , Antibacterianos/química , Cristalografia por Raios X , Farmacorresistência Bacteriana/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Enterococcus faecium/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Pseudomonas aeruginosa/efeitos dos fármacos , Pirróis/química , Pirróis/isolamento & purificação , Pirróis/farmacologia , Streptococcus pneumoniae/efeitos dos fármacos , Vancomicina/farmacologia
16.
J Nat Prod ; 71(12): 2032-5, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19053507

RESUMO

Two new xanthone antibiotics, citreamicin delta (1) and epsilon (2), with potent activity against Gram-positive pathogens including multidrug-resistant Staphylococcus aureus (MDRSA) were discovered. Compounds 1 and 2 exhibited MIC values < 1 microg/mL versus a number of resistant strains. The compounds were obtained from EtOAc extracts of Streptomyces vinaceus and were purified by countercurrent chromatography and reversed-phase HPLC. Their structures were elucidated using primarily NMR and mass spectroscopy.


Assuntos
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Cromatografia Líquida de Alta Pressão , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oxazóis/química , Oxazóis/farmacologia
17.
J Antibiot (Tokyo) ; 61(11): 675-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19168982

RESUMO

Resistance to currently available antibiotics has become a widely recognized crisis in the medical community. To address this, many companies and researchers are refocusing their attention towards natural products, which have an excellent track record of producing effective antibacterial drugs. The AMRI natural product library was screened for activity against multi-drug resistant Staphylococcus aureus (MDRSA). The active samples were counter screened for cytotoxicity against the human hepatocellular carcinoma HepG2 cell line to determine an in vitro therapeutic index (in vitro TI). Those samples with a high in vitro TI were selected for fractionation and dereplication. This led to the discovery of a new anthracycline structure. This metabolite, named mutactimycin E (1), exhibited moderate activity against several gram positive organisms. Here we report the isolation, structure elucidation and biological activities of this new compound.


Assuntos
Antraciclinas/farmacologia , Antibacterianos/farmacologia , Bactérias Gram-Positivas/efeitos dos fármacos , Antraciclinas/química , Antraciclinas/isolamento & purificação , Antraciclinas/toxicidade , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/toxicidade , Linhagem Celular , Hepatócitos/efeitos dos fármacos , Humanos , Estrutura Molecular , Bibliotecas de Moléculas Pequenas , Análise Espectral
18.
Mol Microbiol ; 43(6): 1387-400, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11952893

RESUMO

To address the need for new approaches to antibiotic drug development, we have identified a large number of essential genes for the bacterial pathogen, Staphylococcus aureus, using a rapid shotgun antisense RNA method. Staphylococcus aureus chromosomal DNA fragments were cloned into a xylose-inducible expression plasmid and transformed into S. aureus. Homology comparisons between 658 S. aureus genes identified in this particular antisense screen and the Mycoplasma genitalium genome, which contains 517 genes in total, yielded 168 conserved genes, many of which appear to be essential in M. genitalium and other bacteria. Examples are presented in which expression of an antisense RNA specifically reduces its cognate mRNA. A cell-based, drug-screening assay is also described, wherein expression of an antisense RNA confers specific sensitivity to compounds targeting that gene product. This approach enables facile assay development for high throughput screening for any essential gene, independent of its biochemical function, thereby greatly facilitating the search for new antibiotics.


Assuntos
Proteínas de Bactérias/genética , Marcação de Genes , Genes Essenciais , Genoma Bacteriano , RNA Antissenso , Staphylococcus aureus/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Biologia Computacional/métodos , Mycoplasma/genética , Mycoplasma/metabolismo , Plasmídeos , RNA Mensageiro/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Transformação Bacteriana , Xilose/farmacologia
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