RESUMO
New antibacterial compounds are urgently needed, especially for infections caused by the top-priority Gram-negative bacteria that are increasingly difficult to treat. Lipid A is a key component of the Gram-negative outer membrane and the LpxH enzyme plays an important role in its biosynthesis, making it a promising antibacterial target. Inspired by previously reported ortho-N-methyl-sulfonamidobenzamide-based LpxH inhibitors, novel benzamide substitutions were explored in this work to assess their in vitro activity. Our findings reveal that maintaining wild-type antibacterial activity necessitates removal of the N-methyl group when shifting the ortho-N-methyl-sulfonamide to the meta-position. This discovery led to the synthesis of meta-sulfonamidobenzamide analogs with potent antibacterial activity and enzyme inhibition. Moreover, we demonstrate that modifying the benzamide scaffold can alter blocking of the cardiac voltage-gated potassium ion channel hERG. Furthermore, two LpxH-bound X-ray structures show how the enzyme-ligand interactions of the meta-sulfonamidobenzamide analogs differ from those of the previously reported ortho analogs. Overall, our study has identified meta-sulfonamidobenzamide derivatives as promising LpxH inhibitors with the potential for optimization in future antibacterial hit-to-lead programs.
Assuntos
Antibacterianos , Benzamidas , Desenho de Fármacos , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Benzamidas/farmacologia , Benzamidas/química , Benzamidas/síntese química , Relação Estrutura-Atividade , Humanos , Sulfonamidas/química , Sulfonamidas/farmacologia , Sulfonamidas/síntese química , Estrutura Molecular , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Relação Dose-Resposta a Droga , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Modelos MolecularesRESUMO
Chemical risk assessments typically focus on single substances, often overlooking real-world co-exposures to chemical mixtures. Mixture toxicology studies using representative mixtures can reveal potential chemical interactions, but these do not account for the unique chemical profiles that occur in the blood of diverse individuals. Here we used the H295R steroidogenesis assay to screen personalized mixtures of 24 persistent organic pollutants (POPs) for cytotoxicity and endocrine disruption. Each mixture was reconstructed at a human exposure relevant concentration (1×), as well as at 10- and 100-fold higher concentration (10×, 100×) by acoustic liquid handling based on measured blood concentrations in a Swedish cohort. Among the twelve mixtures tested, nine mixtures decreased the cell viability by 4-18%, primarily at the highest concentration. While the median and maximum mixtures based on the whole study population induced no measurable effects on steroidogenesis at any concentration, the personalized mixture from an individual with the lowest total POPs concentration was the only mixture that affected estradiol synthesis (35% increase at the 100× concentration). Mixtures reconstructed from blood levels of three different individuals stimulated testosterone synthesis at the 1× (11-15%) and 10× concentrations (12-16%), but not at the 100× concentration. This proof-of-principle personalized toxicity study illustrates that population-based representative chemical mixtures may not adequately account for the toxicological risks posed to individuals. It highlights the importance of testing a range of real-world mixtures at relevant concentrations to explore potential interactions and non-monotonic effects. Further toxicological studies of personalized contaminant mixtures could improve chemical risk assessment and advance the understanding of human health, as chemical exposome data become increasingly available.
RESUMO
Many persistent organic pollutants (POPs) are suspected endocrine disruptors and it is important to investigate their effects at low concentrations relevant to human exposure. Here, the OECD test guideline #456 steroidogenesis assay was downscaled to a 96-well microplate format to screen 24 POPs for their effects on viability, and testosterone and estradiol synthesis using the human adrenocortical cell line H295R. The compounds (six polyfluoroalkyl substances, five organochlorine pesticides, ten polychlorinated biphenyls and three polybrominated diphenyl ethers) were tested at human-relevant levels (1 nM to 10 µM). Increased estradiol synthesis, above the OECD guideline threshold of 1.5-fold solvent control, was shown after exposure to 10 µM PCB-156 (153%) and PCB-180 (196%). Interestingly, the base hormone synthesis varied depending on the cell batch. An alternative data analysis using a linear mixed-effects model that include multiple independent experiments and considers batch-dependent variation was therefore applied. This approach revealed small but statistically significant effects on estradiol or testosterone synthesis for 17 compounds. Increased testosterone levels were demonstrated even at 1 nM for PCB-74 (18%), PCB-99 (29%), PCB-118 (16%), PCB-138 (19%), PCB-180 (22%), and PBDE-153 (21%). The MTT assay revealed significant effects on cell viability after exposure to 1 nM of perfluoroundecanoic acid (12%), 3 nM PBDE-153 (9%), and 10 µM of PCB-156 (6%). This shows that some POPs can interfere with endocrine signaling at concentrations found in human blood, highlighting the need for further investigation into the toxicological mechanisms of POPs and their mixtures at low concentrations relevant to human exposure.
Assuntos
Sobrevivência Celular , Disruptores Endócrinos , Poluentes Orgânicos Persistentes , Bifenilos Policlorados , Testosterona , Humanos , Testosterona/biossíntese , Testosterona/metabolismo , Poluentes Orgânicos Persistentes/metabolismo , Disruptores Endócrinos/toxicidade , Disruptores Endócrinos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Éteres Difenil Halogenados/toxicidade , Estradiol/metabolismo , Estrogênios , Linhagem Celular , Praguicidas/toxicidade , Hidrocarbonetos Clorados/toxicidadeRESUMO
Drugs targeting SARS-CoV-2 could have saved millions of lives during the COVID-19 pandemic, and it is now crucial to develop inhibitors of coronavirus replication in preparation for future outbreaks. We explored two virtual screening strategies to find inhibitors of the SARS-CoV-2 main protease in ultralarge chemical libraries. First, structure-based docking was used to screen a diverse library of 235 million virtual compounds against the active site. One hundred top-ranked compounds were tested in binding and enzymatic assays. Second, a fragment discovered by crystallographic screening was optimized guided by docking of millions of elaborated molecules and experimental testing of 93 compounds. Three inhibitors were identified in the first library screen, and five of the selected fragment elaborations showed inhibitory effects. Crystal structures of target-inhibitor complexes confirmed docking predictions and guided hit-to-lead optimization, resulting in a noncovalent main protease inhibitor with nanomolar affinity, a promising in vitro pharmacokinetic profile, and broad-spectrum antiviral effect in infected cells.
Assuntos
Antivirais/farmacologia , Proteases 3C de Coronavírus/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , SARS-CoV-2/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Antivirais/metabolismo , Antivirais/farmacocinética , Domínio Catalítico , Chlorocebus aethiops , Proteases 3C de Coronavírus/química , Inibidores de Cisteína Proteinase/metabolismo , Inibidores de Cisteína Proteinase/farmacocinética , Avaliação Pré-Clínica de Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , SARS-CoV-2/enzimologia , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacocinética , Células VeroRESUMO
Glioblastoma (GBM) is a malignant brain tumor with few therapeutic options. The disease presents with a complex spectrum of genomic aberrations, but the pharmacological consequences of these aberrations are partly unknown. Here, we report an integrated pharmacogenomic analysis of 100 patient-derived GBM cell cultures from the human glioma cell culture (HGCC) cohort. Exploring 1,544 drugs, we find that GBM has two main pharmacological subgroups, marked by differential response to proteasome inhibitors and mutually exclusive aberrations in TP53 and CDKN2A/B. We confirm this trend in cell and in xenotransplantation models, and identify both Bcl-2 family inhibitors and p53 activators as potentiators of proteasome inhibitors in GBM cells. We can further predict the responses of individual cell cultures to several existing drug classes, presenting opportunities for drug repurposing and design of stratified trials. Our functionally profiled biobank provides a valuable resource for the discovery of new treatments for GBM.
Assuntos
Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Terapia de Alvo Molecular , Medicina de Precisão , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Bortezomib/farmacologia , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Redes Reguladoras de Genes/efeitos dos fármacos , Heterogeneidade Genética , Genoma Humano , Glioblastoma/genética , Humanos , Camundongos Endogâmicos BALB C , Mutação/genética , Inibidores de Proteassoma/farmacologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Fanconi anemia is a rare disease clinically characterized by malformations, bone marrow failure and an increased risk of solid tumors and hematologic malignancies. The only therapies available are hematopoietic stem cell transplantation for bone marrow failure or leukemia, and surgical resection for solid tumors. Therefore, there is still an urgent need for new therapeutic options. With this aim, we developed a novel high-content cell-based screening assay to identify drugs with therapeutic potential in FA. RESULTS: A TALEN-mediated FANCA-deficient U2OS cell line was stably transfected with YFP-FANCD2 fusion protein. These cells were unable to form fluorescent foci or to monoubiquitinate endogenous or exogenous FANCD2 upon DNA damage and were more sensitive to mitomycin C when compared to the parental wild type counterpart. FANCA correction by retroviral infection restored the cell line's ability to form FANCD2 foci and ubiquitinate FANCD2. The feasibility of this cell-based system was interrogated in a high content screening of 3802 compounds, including a Prestwick library of 1200 FDA-approved drugs. The potential hits identified were then individually tested for their ability to rescue FANCD2 foci and monoubiquitination, and chromosomal stability in the absence of FANCA. CONCLUSIONS: While, unfortunately, none of the compounds tested were able to restore cellular FANCA-deficiency, our study shows the potential capacity to screen large compound libraries in the context of Fanconi anemia therapeutics in an optimized and cost-effective platform.
Assuntos
Anemia de Fanconi , Dano ao DNA , Avaliação Pré-Clínica de Medicamentos , Anemia de Fanconi/tratamento farmacológico , Anemia de Fanconi/genética , Proteína do Grupo de Complementação A da Anemia de Fanconi/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , HumanosRESUMO
Chemical proteomics encompasses novel drug target deconvolution methods in which compound modification is not required. Herein we use Thermal Proteome Profiling, Functional Identification of Target by Expression Proteomics and multiplexed redox proteomics for deconvolution of auranofin targets to aid elucidation of its mechanisms of action. Auranofin (Ridaura®) was approved for treatment of rheumatoid arthritis in 1985. Because several clinical trials are currently ongoing to repurpose auranofin for cancer therapy, comprehensive characterization of its targets and effects in cancer cells is important. Together, our chemical proteomics tools confirmed thioredoxin reductase 1 (TXNRD1, EC:1.8.1.9) as a main auranofin target, with perturbation of oxidoreductase pathways as the top mechanism of drug action. Additional indirect targets included NFKB2 and CHORDC1. Our comprehensive data can be used as a proteomic signature resource for further analyses of the effects of auranofin. Here we also assessed the orthogonality and complementarity of different chemical proteomics methods that can furnish invaluable mechanistic information and thus the approach can facilitate drug discovery efforts in general.
Assuntos
Auranofina , Preparações Farmacêuticas , Auranofina/farmacologia , Oxirredução , Proteômica , Tiorredoxina Redutase 1/metabolismoRESUMO
The NUDIX enzymes are involved in cellular metabolism and homeostasis, as well as mRNA processing. Although highly conserved throughout all organisms, their biological roles and biochemical redundancies remain largely unclear. To address this, we globally resolve their individual properties and inter-relationships. We purify 18 of the human NUDIX proteins and screen 52 substrates, providing a substrate redundancy map. Using crystal structures, we generate sequence alignment analyses revealing four major structural classes. To a certain extent, their substrate preference redundancies correlate with structural classes, thus linking structure and activity relationships. To elucidate interdependence among the NUDIX hydrolases, we pairwise deplete them generating an epistatic interaction map, evaluate cell cycle perturbations upon knockdown in normal and cancer cells, and analyse their protein and mRNA expression in normal and cancer tissues. Using a novel FUSION algorithm, we integrate all data creating a comprehensive NUDIX enzyme profile map, which will prove fundamental to understanding their biological functionality.
Assuntos
Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Família Multigênica , Pirofosfatases/genética , Células A549 , Linhagem Celular , Linhagem Celular Tumoral , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Filogenia , Pirofosfatases/classificação , Pirofosfatases/metabolismo , Interferência de RNA , Especificidade por Substrato , Nudix HidrolasesRESUMO
A high-throughput screening campaign using a commercial compound library (ChemBridge DiverSET) revealed diverse chemotypes as inhibitors of the human dCTP pyrophosphatase 1 (dCTPase). Triazole, triazolopyrimidine, triazinoindole, quinoline hydrazone and arylpiperazine hits were clustered, confirmed by IC50 determinations, and their preliminary structure-activity-relationships (SAR) and ligand efficiency scores are discussed in this letter.
Assuntos
Inibidores Enzimáticos/farmacologia , Compostos Heterocíclicos/farmacologia , Pirofosfatases/antagonistas & inibidores , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Humanos , Hidrazonas/síntese química , Hidrazonas/química , Hidrazonas/farmacologia , Indóis/síntese química , Indóis/química , Indóis/farmacologia , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/química , Piperazinas/farmacologia , Pirimidinas/síntese química , Pirimidinas/química , Pirimidinas/farmacologia , Pirofosfatases/metabolismo , Quinolinas/síntese química , Quinolinas/química , Quinolinas/farmacologia , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Triazóis/farmacologiaRESUMO
Two screening campaigns using commercial (Chembridge DiverSET) and proprietary (Chemical Biology Consortium Sweden, CBCS) compound libraries, revealed a number of pyridone- and pyrimidinone-derived systems as inhibitors of the human dCTP pyrophosphatase 1 (dCTPase). In this letter, we present their preliminary structure-activity-relationships (SAR) and ligand efficiency scores (LE and LLE).
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Piridonas/química , Piridonas/farmacologia , Pirimidinonas/química , Pirimidinonas/farmacologia , Pirofosfatases/antagonistas & inibidores , Humanos , Ligantes , Pirofosfatases/metabolismo , Relação Estrutura-AtividadeRESUMO
The dCTP pyrophosphatase 1 (dCTPase) is involved in the regulation of the cellular dNTP pool and has been linked to cancer progression. Here we report on the discovery of a series of 3,6-disubstituted triazolothiadiazoles as potent dCTPase inhibitors. Compounds 16 and 18 display good correlation between enzymatic inhibition and target engagement, together with efficacy in a cellular synergy model, deeming them as a promising starting point for hit-to-lead development.
Assuntos
Inibidores Enzimáticos/farmacologia , Pirofosfatases/antagonistas & inibidores , Tiadiazóis/farmacologia , Ensaios de Triagem em Larga Escala , Humanos , Simulação de Acoplamento MolecularRESUMO
Glioblastoma multiforme (GBM, astrocytoma grade IV) is the most common malignant primary brain tumor in adults. Addressing the shortage of effective treatment options for this cancer, we explored repurposing of existing drugs into combinations with potent activity against GBM cells. We report that the phytoalexin pterostilbene is a potentiator of two drugs with previously reported anti-GBM activity, the EGFR inhibitor gefitinib and the antidepressant sertraline. Combinations of either of these two compounds with pterostilbene suppress cell growth, viability, sphere formation and inhibit migration in tumor GBM cell (GC) cultures. The potentiating effect of pterostilbene was observed to a varying degree across a panel of 41 patient-derived GCs, and correlated in a case specific manner with the presence of missense mutation of EGFR and PIK3CA and a focal deletion of the chromosomal region 1p32. We identify pterostilbene-induced cell cycle arrest, synergistic inhibition of MAPK activity and induction of Thioredoxin interacting protein (TXNIP) as possible mechanisms behind pterostilbene's effect. Our results highlight a nontoxic stilbenoid compound as a modulator of anticancer drug response, and indicate that pterostilbene might be used to modulate two anticancer compounds in well-defined sets of GBM patients.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Estilbenos/farmacologia , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Fitogênicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Variações do Número de Cópias de DNA , Sinergismo Farmacológico , Feminino , Gefitinibe , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Mutação , Fenótipo , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Estilbenos/uso terapêutico , TranscriptomaRESUMO
Cancers have dysfunctional redox regulation resulting in reactive oxygen species production, damaging both DNA and free dNTPs. The MTH1 protein sanitizes oxidized dNTP pools to prevent incorporation of damaged bases during DNA replication. Although MTH1 is non-essential in normal cells, we show that cancer cells require MTH1 activity to avoid incorporation of oxidized dNTPs, resulting in DNA damage and cell death. We validate MTH1 as an anticancer target in vivo and describe small molecules TH287 and TH588 as first-in-class nudix hydrolase family inhibitors that potently and selectively engage and inhibit the MTH1 protein in cells. Protein co-crystal structures demonstrate that the inhibitors bind in the active site of MTH1. The inhibitors cause incorporation of oxidized dNTPs in cancer cells, leading to DNA damage, cytotoxicity and therapeutic responses in patient-derived mouse xenografts. This study exemplifies the non-oncogene addiction concept for anticancer treatment and validates MTH1 as being cancer phenotypic lethal.
Assuntos
Enzimas Reparadoras do DNA/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Nucleotídeos/metabolismo , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Animais , Domínio Catalítico , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cristalização , Dano ao DNA , Enzimas Reparadoras do DNA/química , Enzimas Reparadoras do DNA/metabolismo , Nucleotídeos de Desoxiguanina/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Humanos , Masculino , Camundongos , Modelos Moleculares , Conformação Molecular , Terapia de Alvo Molecular , Neoplasias/patologia , Oxirredução/efeitos dos fármacos , Monoéster Fosfórico Hidrolases/química , Monoéster Fosfórico Hidrolases/metabolismo , Pirimidinas/química , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Pirofosfatases/antagonistas & inibidores , Reprodutibilidade dos Testes , Ensaios Antitumorais Modelo de Xenoenxerto , Nudix HidrolasesRESUMO
BACKGROUND: Glioblastoma multiforme (GBM) is the most aggressive brain tumor in adults, and despite state-of-the-art treatment, survival remains poor and novel therapeutics are sorely needed. The aim of the present study was to identify new synergistic drug pairs for GBM. In addition, we aimed to explore differences in drug-drug interactions across multiple GBM-derived cell cultures and predict such differences by use of transcriptional biomarkers. METHODS: We performed a screen in which we quantified drug-drug interactions for 465 drug pairs in each of the 5 GBM cell lines U87MG, U343MG, U373MG, A172, and T98G. Selected interactions were further tested using isobole-based analysis and validated in 5 glioma-initiating cell cultures. Furthermore, drug interactions were predicted using microarray-based transcriptional profiling in combination with statistical modeling. RESULTS: Of the 5 × 465 drug pairs, we could define a subset of drug pairs with strong interaction in both standard cell lines and glioma-initiating cell cultures. In particular, a subset of pairs involving the pharmaceutical compounds rimcazole, sertraline, pterostilbene, and gefitinib showed a strong interaction in a majority of the cell cultures tested. Statistical modeling of microarray and interaction data using sparse canonical correlation analysis revealed several predictive biomarkers, which we propose could be of importance in regulating drug pair responses. CONCLUSION: We identify novel candidate drug pairs for GBM and suggest possibilities to prospectively use transcriptional biomarkers to predict drug interactions in individual cases.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Glioblastoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carbazóis/uso terapêutico , Linhagem Celular Tumoral , Interações Medicamentosas , Gefitinibe , Humanos , Quinazolinas/uso terapêutico , Sertralina/uso terapêutico , Estilbenos/uso terapêuticoRESUMO
Knowledge of the spatial distribution of juvenile cod is essential for obtaining precise recruitment data to conduct sustainable management of the eastern and western Baltic cod stocks. In this study, the horizontal and vertical distribution and density patterns of settled juvenile 0- and 1-group Baltic cod are determined, and their nursery areas are localised according to the environmental factors affecting them. Comparative statistical analyses of biological, hydrographic and hydroacoustic data are carried out based on standard ICES demersal trawl surveys and special integrated trawl and acoustic research surveys. Horizontal distribution maps for the 2001-2010 cohorts of juvenile cod are further generated by applying a statistical log-Gaussian Cox process model to the standard trawl survey data. The analyses indicate size-dependent horizontal and distinct vertical and diurnal distribution patterns related to the seabed topography, water layer depth, and the presence of hydrographic frontal zones (pycnoclines) as well as intraspecific patterns in relation to the presence of adult cod. The extent of the nursery areas also depends on the cod year class strength. Juvenile cod (≥3 cm) are present in all areas of the central Baltic Sea (CBS), showing broad dispersal. However, their highest density in the Baltic Basins is found at localities with a 40-70 m bottom depth in waters with oxygen concentrations above 2 ml O2.l⻹ and temperatures above 5°C. The smallest juveniles are also found in deep sea localities down to a 100 m depth and at oxygen concentrations between 2-4 ml O2.l⻹. The vertical, diurnally stratified and repeated trawling and hydroacoustic target strength-depth distributions obtained from the special surveys show juvenile cod concentrations in frontal zone water layers (pycnocline). However, the analyses indicate that in the CBS, juvenile cod of all sizes do not appear to aggregate in dense schooling patterns, which differs from what has been reported from the North Sea.
Assuntos
Gadus morhua/crescimento & desenvolvimento , Oceanos e Mares , Animais , Modelos Estatísticos , Densidade Demográfica , Dinâmica Populacional , Água do MarRESUMO
About one-third of oestrogen receptor alpha-positive breast cancer patients treated with tamoxifen relapse. Here we identify the nuclear receptor retinoic acid receptor alpha as a marker of tamoxifen resistance. Using quantitative mass spectrometry-based proteomics, we show that retinoic acid receptor alpha protein networks and levels differ in a tamoxifen-sensitive (MCF7) and a tamoxifen-resistant (LCC2) cell line. High intratumoural retinoic acid receptor alpha protein levels also correlate with reduced relapse-free survival in oestrogen receptor alpha-positive breast cancer patients treated with adjuvant tamoxifen solely. A similar retinoic acid receptor alpha expression pattern is seen in a comparable independent patient cohort. An oestrogen receptor alpha and retinoic acid receptor alpha ligand screening reveals that tamoxifen-resistant LCC2 cells have increased sensitivity to retinoic acid receptor alpha ligands and are less sensitive to oestrogen receptor alpha ligands compared with MCF7 cells. Our data indicate that retinoic acid receptor alpha may be a novel therapeutic target and a predictive factor for oestrogen receptor alpha-positive breast cancer patients treated with adjuvant tamoxifen.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Resistencia a Medicamentos Antineoplásicos/genética , Receptor alfa de Estrogênio/genética , Regulação Neoplásica da Expressão Gênica , Recidiva Local de Neoplasia , Receptores do Ácido Retinoico/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/uso terapêutico , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Quimioterapia Adjuvante , Receptor alfa de Estrogênio/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Especificidade de Órgãos , Receptores do Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico , Análise de Sobrevida , Tamoxifeno/uso terapêuticoRESUMO
Simulation of ultrasound images based on computed tomography (CT) data has previously been performed with different approaches. Shadow effects are normally pronounced in ultrasound images, so they should be included in the simulation. In this study, a method to capture the shadow effects has been developed, which makes the simulated ultrasound images appear more realistic. The method using a focused beam tracing model gives diffuse shadows that are similar to the ones observed in measurements on real objects. Ultrasound images of a cod (Gadus morhua) were obtained with a BK Medical 2202 ProFocus ultrasound scanner (BK Medical, Herlev, Denmark) equipped with a dedicated research interface giving access to beamformed radio frequency data. CT images were obtained with an Aquilion ONE Toshiba CT scanner (Toshiba Medical Systems Corp., Tochigi, Japan). CT data were mapped from Hounsfield units to backscatter strength, attenuation coefficients, and characteristic acoustic impedance. The focused beam tracing model was used to create maps of the transmission coefficient and scattering strength maps. Field II was then used to simulate an ultrasound image of 38.9 × 55.3 × 4.5 mm, using 10(6) point scatterers. As there is no quantitative method to assess quality of a simulated ultrasound image compared to a measured one, visual inspection was used for evaluation.
RESUMO
A proteomics approach was used to identify liver proteins that displayed altered levels in mice following treatment with a candidate drug. Samples from livers of mice treated with candidate drug or untreated were prepared, quantified, labeled with CyDye DIGE Fluors, and subjected to two-dimensional electrophoresis. Following scanning and imaging of gels from three different isoelectric focusing intervals (3-10, 7-11, 6.2-7.5), automated spot handling was performed on a large number of gel spots including those found to differ more than 20% between the treated and untreated condition. Subsequently, differentially regulated proteins were subjected to a three-step approach of mass spectrometry using (a) matrix-assisted laser desorption/ionization time-of-flight mass spectrometry peptide mass fingerprinting, (b) post-source decay utilizing chemically assisted fragmentation, and (c) liquid chromatography-tandem mass spectrometry. Using this approach we have so far resolved 121 differentially regulated proteins following treatment of mice with the candidate drug and identified 110 of these using mass spectrometry. Such data can potentially give improved molecular insight into the metabolism of drugs as well as the proteins involved in potential toxicity following the treatment. The differentially regulated proteins could be used as targets for metabolic studies or as markers for toxicity.