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1.
Cell Rep ; 43(3): 113826, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38412093

RESUMO

Anaplastic thyroid carcinoma is arguably the most lethal human malignancy. It often co-occurs with differentiated thyroid cancers, yet the molecular origins of its aggressivity are unknown. We sequenced tumor DNA from 329 regions of thyroid cancer, including 213 from patients with primary anaplastic thyroid carcinomas. We also whole genome sequenced 9 patients using multi-region sequencing of both differentiated and anaplastic thyroid cancer components. Using these data, we demonstrate thatanaplastic thyroid carcinomas have a higher burden of mutations than other thyroid cancers, with distinct mutational signatures and molecular subtypes. Further, different cancer driver genes are mutated in anaplastic and differentiated thyroid carcinomas, even those arising in a single patient. Finally, we unambiguously demonstrate that anaplastic thyroid carcinomas share a genomic origin with co-occurring differentiated carcinomas and emerge from a common malignant field through acquisition of characteristic clonal driver mutations.


Assuntos
Adenocarcinoma , Carcinoma Anaplásico da Tireoide , Neoplasias da Glândula Tireoide , Humanos , Carcinoma Anaplásico da Tireoide/genética , Carcinoma Anaplásico da Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Mutação/genética , Genômica
2.
Eur Arch Otorhinolaryngol ; 280(2): 633-641, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35841407

RESUMO

PURPOSE: Superficial siderosis, a progressive, debilitating, neurological disease, often presents with bilateral impairment of auditory and vestibular function. We highlight that superficial siderosis is often due to a repairable spinal dural defect of the type that can also cause spontaneous intracranial hypotension. METHODS: Retrospective chart review of five patients presenting with moderate to severe, progressive bilateral sensorineural hearing loss as well as vestibular loss. All patients had developed superficial siderosis from spinal dural defects: three after trauma, one after spinal surgery and one from a thoracic discogenic microspur. RESULTS: The diagnosis was made late in all five patients; despite surgical repair in four, hearing and vestibular loss failed to improve. CONCLUSIONS: In patients presenting with progressive bilateral sensorineural hearing loss, superficial siderosis should be considered as a possible cause. If these patients also have bilateral vestibular loss, cerebellar impairment and anosmia, then the diagnosis is likely and the inevitable disease progress might be halted by finding and repairing the spinal dural defect.


Assuntos
Perda Auditiva Neurossensorial , Siderose , Humanos , Siderose/complicações , Siderose/diagnóstico , Estudos Retrospectivos , Audição , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/etiologia , Imageamento por Ressonância Magnética/efeitos adversos
3.
Cell Syst ; 12(8): 827-838.e5, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34146471

RESUMO

The accurate identification and quantitation of RNA isoforms present in the cancer transcriptome is key for analyses ranging from the inference of the impacts of somatic variants to pathway analysis to biomarker development and subtype discovery. The ICGC-TCGA DREAM Somatic Mutation Calling in RNA (SMC-RNA) challenge was a crowd-sourced effort to benchmark methods for RNA isoform quantification and fusion detection from bulk cancer RNA sequencing (RNA-seq) data. It concluded in 2018 with a comparison of 77 fusion detection entries and 65 isoform quantification entries on 51 synthetic tumors and 32 cell lines with spiked-in fusion constructs. We report the entries used to build this benchmark, the leaderboard results, and the experimental features associated with the accurate prediction of RNA species. This challenge required submissions to be in the form of containerized workflows, meaning each of the entries described is easily reusable through CWL and Docker containers at https://github.com/SMC-RNA-challenge. A record of this paper's transparent peer review process is included in the supplemental information.


Assuntos
Neoplasias , Humanos , Neoplasias/genética , Isoformas de Proteínas/genética , RNA/genética , RNA-Seq , Análise de Sequência de RNA
5.
Front Pediatr ; 8: 267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32537446

RESUMO

Objectives: 1 Measure serial serum intestinal fatty acid binding protein levels in infants undergoing cardiac surgery with cardiopulmonary bypass to evaluate for evidence of early post-operative enterocyte injury. 2 Determine the association between immediate post-operative circulating intestinal fatty acid binding protein levels and subsequent development of necrotizing enterocolitis. Design: Observational cohort study. Intestinal fatty acid binding protein was measured pre-operatively, at rewarming, and at 6 and 24 h post-operatively. Percent of goal enteral kilocalories on post-operative day 5 and episodes of necrotizing enterocolitis were determined. Multivariable analysis assessed for factors independently associated with clinical feeding outcomes and suspected/definite necrotizing enterocolitis. Setting: Quaternary free-standing children's hospital pediatric cardiac intensive care unit. Patients: 103 infants <120 days of age undergoing cardiothoracic surgery with cardiopulmonary bypass. Interventions: None. Results: Median pre-operative intestinal fatty acid binding protein level was 3.93 ng/ml (range 0.24-51.32). Intestinal fatty acid binding protein levels rose significantly at rewarming (6.35 ng/ml; range 0.54-56.97; p = 0.008), continued to rise slightly by 6 h (6.57 ng/ml; range 0.75-112.04; p = 0.016), then decreased by 24 h (2.79 ng/ml; range 0.03-81.74; p < 0.0001). Sixteen subjects (15.7%) developed modified Bell criteria Stage 1 necrotizing enterocolitis and 9 subjects (8.8%) developed Stage 2 necrotizing enterocolitis. Infants who developed necrotizing enterocolitis demonstrated a significantly higher distribution of intestinal fatty acid binding protein levels at both 6 h (p = 0.005) and 24 h (p = 0.005) post-operatively. On multivariable analysis, intestinal fatty acid binding protein was not associated with percentage of goal enteral kilocalories delivered on post-operative day 5. Higher intestinal fatty acid binding protein was independently associated with subsequent development of suspected/definite necrotizing enterocolitis (4% increase in odds of developing necrotizing enterocolitis for each unit increase in intestinal fatty acid binding protein; p = 0.0015). Conclusions: Intestinal fatty acid binding protein levels rise following infant cardiopulmonary bypass, indicating early post-operative enterocyte injury. Intestinal fatty acid binding protein was not associated with percent of goal enteral nutrition achieved on post-operative day 5, likely due to protocolized feeding advancement based on clinically observable factors. Higher intestinal fatty acid binding protein at 6 h post-operatively was independently associated with subsequent development of necrotizing enterocolitis and may help identify patients at risk for this important complication.

6.
J Natl Cancer Inst ; 112(3): 247-255, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31161221

RESUMO

BACKGROUND: The development of noninvasive tests for the early detection of aggressive prostate tumors is a major unmet clinical need. miRNAs are promising noninvasive biomarkers: they play essential roles in tumorigenesis, are stable under diverse analytical conditions, and can be detected in body fluids. METHODS: We measured the longitudinal stability of 673 miRNAs by collecting serial urine samples from 10 patients with localized prostate cancer. We then measured temporally stable miRNAs in an independent training cohort (n = 99) and created a biomarker predictive of Gleason grade using machine-learning techniques. Finally, we validated this biomarker in an independent validation cohort (n = 40). RESULTS: We found that each individual has a specific urine miRNA fingerprint. These fingerprints are temporally stable and associated with specific biological functions. We identified seven miRNAs that were stable over time within individual patients and integrated them with machine-learning techniques to create a novel biomarker for prostate cancer that overcomes interindividual variability. Our urine biomarker robustly identified high-risk patients and achieved similar accuracy as tissue-based prognostic markers (area under the receiver operating characteristic = 0.72, 95% confidence interval = 0.69 to 0.76 in the training cohort, and area under the receiver operating characteristic curve = 0.74, 95% confidence interval = 0.55 to 0.92 in the validation cohort). CONCLUSIONS: These data highlight the importance of quantifying intra- and intertumoral heterogeneity in biomarker development. This noninvasive biomarker may usefully supplement invasive or expensive radiologic- and tissue-based assays.


Assuntos
MicroRNAs/genética , MicroRNAs/urina , Neoplasias da Próstata/genética , Neoplasias da Próstata/urina , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/urina , Carcinogênese , Estudos de Coortes , Humanos , Estudos Longitudinais , Masculino , Gradação de Tumores , Prognóstico , Neoplasias da Próstata/patologia , Reprodutibilidade dos Testes , Transcriptoma
7.
PLoS One ; 14(8): e0219747, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31386671

RESUMO

Alternative splicing is a co-transcriptional mechanism that generates protein diversity by including or excluding exons in different combinations, thereby expanding the diversity of protein isoforms of a single gene. Abnormalities in this process can result in deleterious effects to human health, and several xenobiotics are known to interfere with splicing regulation through multiple mechanisms. These changes could lead to human diseases such as cancer, neurological disorders, autoimmune diseases, and developmental disorders. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant generated as a byproduct of various industrial activities. Exposure to this dioxin has been linked to a wide range of pathologies through the alteration of multiple cellular processes. However, the effects of TCDD exposure on alternative splicing have not yet been studied. Here, we investigated whether a single po. dose of 5 µg/kg or 500 µg/kg TCDD influence hepatic alternative splicing in adult male C57BL/6Kou mouse. We identified several genes whose alternative splicing of precursor messenger RNAs was modified following TCDD exposure. In particular, we demonstrated that alternative splicing of Cyp1a1, Ahrr, and Actn1 was significantly altered after TCDD treatment. These findings show that the exposure to TCDD has an impact on alternative-splicing, and suggest a new avenue for understanding TCDD-mediated toxicity and pathogenesis.


Assuntos
Processamento Alternativo/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Dibenzodioxinas Policloradas/toxicidade , Animais , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos C57BL
8.
JCI Insight ; 4(8)2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30996141

RESUMO

Cystic fibrosis (CF) is characterized by increased mucus viscosity and delayed mucociliary clearance that contributes to progressive decline of lung function. Mucus in the respiratory and GI tract is excessively adhesive in the presence of airway dehydration and excess extracellular Ca2+ upon mucin release, promoting hyperviscous, densely packed mucins characteristic of CF. Therapies that target mucins directly through ionic interactions remain unexploited. Here we show that poly (acetyl, arginyl) glucosamine (PAAG), a polycationic biopolymer suitable for human use, interacts directly with mucins in a Ca2+-sensitive manner to reduce CF mucus viscoelasticity and improve its transport. Notably, PAAG induced a linear structure of purified MUC5B and altered its sedimentation profile and viscosity, indicative of proper mucin expansion. In vivo, PAAG nebulization improved mucociliary transport in CF rats with delayed mucus clearance, and cleared mucus plugging in CF ferrets. This study demonstrates the potential use of a synthetic glycopolymer PAAG as a molecular agent that could benefit patients with a broad array of mucus diseases.


Assuntos
Fibrose Cística/tratamento farmacológico , Glucosamina/análogos & derivados , Mucina-5B/metabolismo , Depuração Mucociliar/efeitos dos fármacos , Muco/efeitos dos fármacos , Polímeros/farmacologia , Animais , Fibrose Cística/genética , Fibrose Cística/patologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Modelos Animais de Doenças , Furões , Glucosamina/farmacologia , Glucosamina/uso terapêutico , Humanos , Camundongos , Camundongos Endogâmicos CFTR , Mucina-5B/química , Muco/metabolismo , Polímeros/uso terapêutico , Estrutura Quaternária de Proteína/efeitos dos fármacos , Ratos , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/patologia , Viscosidade/efeitos dos fármacos
9.
Shock ; 51(3): 328-336, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29664834

RESUMO

OBJECTIVE: Infant cardiopulmonary bypass (CPB) increases intestinal permeability leading to endotoxemia. Alkaline phosphatase (AP) reduces endotoxin toxicity in vitro but its effects on endotoxemia in human disease are poorly understood. We assessed the association between serum AP activity and endotoxemia in infants undergoing CPB and determined the effect of ex vivo addition of AP on endotoxemia. METHODS: Prospective cohort study of 62 infants ≤120 days of age undergoing CPB. AP activity and Endotoxin Activity Assay (EAA) were measured pre-operatively, during rewarming, and 24 h after cardiac intensive care unit admission. In 22 subjects, EAA was measured in pre-operative and rewarming whole blood samples with/without addition of 1,600 U/L of human liver AP. RESULTS: AP activity decreased during CPB (mean decrease 94.8U/L; P < 0.0001). Median EAA was 0.41 pre-operation, rose to 0.52 (P < 0.05) during rewarming, and remained stably elevated at 24 h. Subjects with low pre-operative AP activity had significantly higher pre-operative (0.47 vs. 0.36; P < 0.05) and rewarming (0.59 vs. 0.43; P < 0.01) EAA with a trend toward higher EAA at 24 h (0.52 vs. 0.45; P = 0.12). Subjects with low rewarming AP activity showed similar differences that did not reach statistical significance. Ex vivo addition of human liver AP decreased pre-operative EAA by 29% (P < 0.001) and rewarming EAA by 51% (P < 0.0001). CONCLUSION: Endotoxemia is common in infants undergoing CPB. Native AP activity and endotoxemia are inversely related and ex vivo addition of exogenous AP reduces whole blood EAA. Future research should evaluate AP as a therapy to reduce the harmful effects of endotoxemia following infant CPB.


Assuntos
Fosfatase Alcalina/administração & dosagem , Ponte Cardiopulmonar/efeitos adversos , Endotoxemia , Endotoxinas/sangue , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/epidemiologia , Endotoxemia/sangue , Endotoxemia/epidemiologia , Endotoxemia/etiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Tempo
10.
Nat Commun ; 8(1): 656, 2017 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-28939825

RESUMO

Nuclear mutations are well known to drive tumor incidence, aggression and response to therapy. By contrast, the frequency and roles of mutations in the maternally inherited mitochondrial genome are poorly understood. Here we sequence the mitochondrial genomes of 384 localized prostate cancer patients, and identify a median of one mitochondrial single-nucleotide variant (mtSNV) per patient. Some of these mtSNVs occur in recurrent mutational hotspots and associate with aggressive disease. Younger patients have fewer mtSNVs than those who diagnosed at an older age. We demonstrate strong links between mitochondrial and nuclear mutational profiles, with co-occurrence between specific mutations. For example, certain control region mtSNVs co-occur with gain of the MYC oncogene, and these mutations are jointly associated with patient survival. These data demonstrate frequent mitochondrial mutation in prostate cancer, and suggest interplay between nuclear and mitochondrial mutational profiles in prostate cancer.In prostate cancer, the role of mutations in the maternally-inherited mitochondrial genome are not well known. Here, the authors demonstrate frequent, age-dependent mitochondrial mutation in prostate cancer. Strong links between mitochondrial and nuclear mutational profiles are associated with clinical aggressivity.


Assuntos
Adenocarcinoma/genética , DNA Mitocondrial/genética , Mutação Puntual , Neoplasias da Próstata/genética , Adenocarcinoma/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Genes myc , Estudos de Associação Genética , Genoma Mitocondrial , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Neoplasias da Próstata/patologia , Análise de Sobrevida
11.
Arch Toxicol ; 91(1): 325-338, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27136898

RESUMO

2,3,7,8 Tetrachlorodibenzo-p-dioxin (TCDD) is an aromatic, long-lived environmental contaminant. While the pathogenesis of TCDD-induced toxicity is poorly understood, it has been shown that the aryl hydrocarbon receptor (AHR) is required. However, the specific transcriptomic changes that lead to toxic outcomes have not yet been identified. We previously identified a panel of 33 genes that respond to TCDD treatment in two TCDD-sensitive rodent species. To identify genes involved in the onset of hepatic toxicity, we explored 25 of these in-depth using liver from two rat strains: the TCDD-resistant Han/Wistar (H/W) and the TCDD-sensitive Long-Evans (L-E). Time course and dose-response analyses of mRNA abundance following TCDD insult indicate that eight genes are similarly regulated in livers of both strains of rat, suggesting that they are not central to the severe L-E-specific TCDD-induced toxicities. The remaining 17 genes exhibited various divergent mRNA abundances between L-E and H/W strains after TCDD treatment. Several genes displayed a biphasic response where the initial response to TCDD treatment was followed by a secondary response, usually of larger magnitude in L-E liver. This secondary response was most often an exaggeration of the original TCDD-induced response. Only cytochrome b5 type A (microsomal) (Cyb5a) had equivalent TCDD sensitivity to the prototypic AHR-responsive cytochrome P450, family 1, subfamily a, polypeptide 1 (Cyp1a1), while six genes were less sensitive. Four genes showed an early inter-strain difference that was sustained throughout most of the time course (atypical chemokine receptor 3 (Ackr3), collagen, type XVIII, alpha 1 (Col18a1), Cyb5a and glutamate dehydrogenase 1 (Glud1)), and of those genes examined in this study, are most likely to represent genes involved in the pathogenesis of TCDD-induced hepatotoxicity in L-E rats.


Assuntos
Carcinógenos Ambientais/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , RNA Mensageiro/metabolismo , Animais , Animais não Endogâmicos , Carcinógenos Ambientais/administração & dosagem , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Colágeno Tipo VIII/agonistas , Colágeno Tipo VIII/antagonistas & inibidores , Colágeno Tipo VIII/genética , Colágeno Tipo VIII/metabolismo , Citocromos b5/antagonistas & inibidores , Citocromos b5/química , Citocromos b5/genética , Citocromos b5/metabolismo , Relação Dose-Resposta a Droga , Resistência a Medicamentos , Feminino , Perfilação da Expressão Gênica , Glutamato Desidrogenase , Cinética , Fígado/enzimologia , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Dibenzodioxinas Policloradas/administração & dosagem , Ratos Long-Evans , Receptores CXCR/agonistas , Receptores CXCR/antagonistas & inibidores , Receptores CXCR/genética , Receptores CXCR/metabolismo , Receptores de Glutamato/química , Receptores de Glutamato/genética , Receptores de Glutamato/metabolismo
12.
Nat Genet ; 47(7): 736-45, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26005866

RESUMO

Herein we provide a detailed molecular analysis of the spatial heterogeneity of clinically localized, multifocal prostate cancer to delineate new oncogenes or tumor suppressors. We initially determined the copy number aberration (CNA) profiles of 74 patients with index tumors of Gleason score 7. Of these, 5 patients were subjected to whole-genome sequencing using DNA quantities achievable in diagnostic biopsies, with detailed spatial sampling of 23 distinct tumor regions to assess intraprostatic heterogeneity in focal genomics. Multifocal tumors are highly heterogeneous for single-nucleotide variants (SNVs), CNAs and genomic rearrangements. We identified and validated a new recurrent amplification of MYCL, which is associated with TP53 deletion and unique profiles of DNA damage and transcriptional dysregulation. Moreover, we demonstrate divergent tumor evolution in multifocal cancer and, in some cases, tumors of independent clonal origin. These data represent the first systematic relation of intraprostatic genomic heterogeneity to predicted clinical outcome and inform the development of novel biomarkers that reflect individual prognosis.


Assuntos
Neoplasias da Próstata/genética , Linhagem Celular Tumoral , Variações do Número de Cópias de DNA , Estudos de Associação Genética , Heterogeneidade Genética , Genoma Humano , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Mutação Puntual , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-myc/genética
13.
Am J Respir Crit Care Med ; 190(4): 421-32, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25029666

RESUMO

RATIONALE: The mechanisms underlying cystic fibrosis (CF) lung disease pathogenesis are unknown. OBJECTIVES: To establish mechanisms linking anion transport with the functional microanatomy, we evaluated normal and CF piglet trachea as well as adult swine trachea in the presence of selective anion inhibitors. METHODS: We investigated airway functional microanatomy using microoptical coherence tomography, a new imaging modality that concurrently quantifies multiple functional parameters of airway epithelium in a colocalized fashion. MEASUREMENTS AND MAIN RESULTS: Tracheal explants from wild-type swine demonstrated a direct link between periciliary liquid (PCL) hydration and mucociliary transport (MCT) rates, a relationship frequently invoked but never experimentally confirmed. However, in CF airways this relationship was completely disrupted, with greater PCL depths associated with slowest transport rates. This disrupted relationship was recapitulated by selectively inhibiting bicarbonate transport in vitro and ex vivo. CF mucus exhibited increased viscosity in situ due to the absence of bicarbonate transport, explaining defective MCT that occurs even in the presence of adequate PCL hydration. CONCLUSIONS: An inherent defect in CF airway surface liquid contributes to delayed MCT beyond that caused by airway dehydration alone and identifies a fundamental mechanism underlying the pathogenesis of CF lung disease in the absence of antecedent infection or inflammation.


Assuntos
Fibrose Cística/patologia , Fibrose Cística/fisiopatologia , Epitélio/fisiopatologia , Traqueia/patologia , Traqueia/fisiopatologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Epitélio/patologia , Humanos , Técnicas In Vitro , Depuração Mucociliar/fisiologia , Suínos , Tomografia de Coerência Óptica/métodos
14.
BMC Bioinformatics ; 15: 78, 2014 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-24646301

RESUMO

BACKGROUND: Chromothripsis, a newly discovered type of complex genomic rearrangement, has been implicated in the evolution of several types of cancers. To date, it has been described in bone cancer, SHH-medulloblastoma and acute myeloid leukemia, amongst others, however there are still no formal or automated methods for detecting or annotating it in high throughput sequencing data. As such, findings of chromothripsis are difficult to compare and many cases likely escape detection altogether. RESULTS: We introduce ShatterProof, a software tool for detecting and quantifying chromothriptic events. ShatterProof takes structural variation calls (translocations, copy-number variations, short insertions and loss of heterozygosity) produced by any algorithm and using an operational definition of chromothripsis performs robust statistical tests to accurately predict the presence and location of chromothriptic events. Validation of our tool was conducted using clinical data sets including matched normal, prostate cancer samples in addition to the colorectal cancer and SCLC data sets used in the original description of chromothripsis. CONCLUSIONS: ShatterProof is computationally efficient, having low memory requirements and near linear computation time. This allows it to become a standard component of sequencing analysis pipelines, enabling researchers to routinely and accurately assess samples for chromothripsis. Source code and documentation can be found at http://search.cpan.org/~sgovind/Shatterproof.


Assuntos
Aberrações Cromossômicas , Rearranjo Gênico/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Software , Algoritmos , Variações do Número de Cópias de DNA/genética , Humanos , Masculino , Neoplasias/genética , Análise de Sequência de DNA
15.
Toxicol Appl Pharmacol ; 274(3): 445-54, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24355419

RESUMO

Despite several decades of research, the complete mechanism by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other xenobiotic agonists of the aryl hydrocarbon receptor (AHR) cause toxicity remains unclear. While it has been shown that the AHR is required for all major manifestations of toxicity, the specific downstream changes involved in the development of toxic phenotypes remain unknown. Here we examine a panel of 13 genes that are AHR-regulated in many species and tissues. We profiled their hepatic mRNA abundances in two rat strains with very different sensitivities to TCDD: the TCDD-sensitive Long-Evans (Turku/AB; L-E) and the TCDD-resistant Han/Wistar (Kuopio; H/W). We evaluated doses ranging from 0 to 3000µg/kg at 19h after TCDD exposure and time points ranging from 1.5 to 384h after exposure to 100µg/kg TCDD. Twelve of 13 genes responded to TCDD in at least one strain, and seven of these showed statistically significant inter-strain differences in the time course analysis (Aldh3a1, Cyp1a2, Cyp1b1, Cyp2a1, Fmo1, Nfe2l2 and Nqo1). Cyp2s1 did not respond to TCDD in either rat strain. Five genes exhibited biphasic responses to TCDD insult (Ahrr, Aldh3a1, Cyp1b1, Nfe2l2 and Nqo1), suggesting a secondary event, such as association with additional transcriptional modulators. Of the 12 genes that responded to TCDD during the dose-response analysis, none had an ED50 equivalent to that of Cyp1a1, the most sensitive gene in this study, while nine genes responded to doses at least 10-100 fold higher, in at least one strain (Ahrr (L-E), Aldh3a1 (both), Cyp1a2 (both), Cyp1b1 (both), Cyp2a1 (L-E), Inmt (both), Nfe2l2 (L-E), Nqo1 (L-E) and Tiparp (both)). These data shed new light on the association of the AHR target genes with TCDD toxicity, and in particular the seven genes exhibiting strain-specific differences represent strong candidate mediators of Type-II toxicities.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Citocromo P-450 CYP1A2 , Citocromo P-450 CYP1B1 , Família 2 do Citocromo P450 , Citocromos/genética , Citocromos/metabolismo , Relação Dose-Resposta a Droga , Fígado/metabolismo , Masculino , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Long-Evans , Ratos Wistar , Esteroide Hidroxilases/genética , Esteroide Hidroxilases/metabolismo , Xenobióticos/toxicidade
16.
Nucleic Acids Res ; 32(11): 3462-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15226411

RESUMO

The c-Myc transcription factor represses the mRNA expression of the platelet-derived growth factor receptor beta gene (PDGFRB). Using chromatin immunoprecipitation, we show that c-Myc binds to the proximal promoter of the PDGFRB gene in proliferating rat fibroblasts. Interestingly, mutant c-Myc proteins that are unable to repress PDGFRB gene expression, c-Myc(dBR) and c-Myc(d106-143), are still able to bind to the promoter in vivo. Hence, promoter-binding and repression of PDGFRB by c-Myc are separable activities. We also show that Myc repression of PDGFRB is not dependent on previously described or known transactivator-binding regions, suggesting Myc may be recruited to the promoter by multiple or yet unidentified transcription factors. In the presence of intact promoter-binding by Myc, trichostatin A (TSA) can block Myc repression of PDGFRB in vivo, again demonstrating that promoter-binding and repression are separable. Taken together, we hypothesize that Myc repression of PDGFRB expression occurs by a multi-step mechanism in which repression is initiated after Myc is recruited to the promoter.


Assuntos
Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Proteínas Repressoras/metabolismo , Animais , Sítios de Ligação , Proteínas de Ligação a DNA/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Ácidos Hidroxâmicos/farmacologia , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , RNA Polimerase II/metabolismo , Ratos , Proteínas Repressoras/antagonistas & inibidores , Transativadores/metabolismo
17.
Curr Biol ; 13(10): 882-6, 2003 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-12747840

RESUMO

The c-myc proto-oncogene encodes a transcription factor, c-Myc, which is deregulated and/or overexpressed in many human cancers. Despite c-Myc's importance, the identity of Myc-regulated genes and the mechanism by which Myc regulates these genes remain unclear. By combining chromatin immunoprecipitation with CpG island arrays, we identified 177 human genomic loci that are bound by Myc in vivo. Analyzing a cohort of known and novel Myc target genes showed that Myc-associated protein X, Max, also bound to these regulatory regions. Indeed, Max is bound to these loci in the presence or absence of Myc. The Myc:Max interaction is essential for Myc-dependent transcriptional activation; however, we show that Max bound targets also include Myc-repressed genes. Moreover, we show that the interaction between Myc and Max is essential for gene repression to occur. Taken together, the identification and analysis of Myc bound target genes supports a model whereby Max plays an essential and universal role in the mechanism of Myc-dependent transcriptional regulation.


Assuntos
Ilhas de CpG/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Genes myc/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Genes Reguladores/genética , Células HL-60 , Humanos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proto-Oncogene Mas , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
18.
J Hypertens ; 20(12): 2513-7, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12473877

RESUMO

OBJECTIVE: To determine the relative importance of recognised risk factors for non-haemorrhagic stroke, including serum cholesterol and the effect of cholesterol-lowering therapy, on the occurrence of non-haemorrhagic stroke in patients enrolled in the LIPID (Long-term Intervention with Pravastatin in Ischaemic Disease) study. DESIGN: The LIPID study was a placebo-controlled, double-blind trial of the efficacy on coronary heart disease mortality of pravastatin therapy over 6 years in 9014 patients with previous acute coronary syndromes and baseline total cholesterol of 4-7 mmol/l. Following identification of patients who had suffered non-haemorrhagic stroke, a pre-specified secondary end point, multivariate Cox regression was used to determine risk in the total population. Time-to-event analysis was used to determine the effect of pravastatin therapy on the rate of non-haemorrhagic stroke. RESULTS: There were 388 non-haemorrhagic strokes in 350 patients. Factors conferring risk of future non-haemorrhagic stroke were age, atrial fibrillation, prior stroke, diabetes, hypertension, systolic blood pressure, cigarette smoking, body mass index, male sex and creatinine clearance. Baseline lipids did not predict non-haemorrhagic stroke. Treatment with pravastatin reduced non-haemorrhagic stroke by 23% (P = 0.016) when considered alone, and 21% (P = 0.024) after adjustment for other risk factors. CONCLUSIONS: The study confirmed the variety of risk factors for non-haemorrhagic stroke. From the risk predictors, a simple prognostic index was created for non-haemorrhagic stroke to identify a group of patients at high risk. Treatment with pravastatin resulted in significant additional benefit after allowance for risk factors.


Assuntos
Anticolesterolemiantes/uso terapêutico , Doença das Coronárias/complicações , Doença das Coronárias/tratamento farmacológico , Pravastatina/uso terapêutico , Acidente Vascular Cerebral/etiologia , Idoso , Pressão Sanguínea , Doença das Coronárias/mortalidade , Doença das Coronárias/fisiopatologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Acidente Vascular Cerebral/prevenção & controle
19.
J Biol Chem ; 277(40): 36921-30, 2002 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-12145275

RESUMO

The c-myc proto-oncogene can direct a diverse array of biological activities, including cell cycle progression, apoptosis, and differentiation. It is believed that Myc can affect this wide variety of activities by functioning as a regulator of gene transcription, although few targets have been identified to date. To delineate the molecular program regulated downstream of Myc, we used a cDNA microarray approach and identified 52 putative targets out of >6000 cDNAs analyzed. To further distinguish the subset of genes whose regulation was dependent upon Myc per se from those regulated in response to activation of general mitogenic or apoptotic programs, the putative cDNA targets were then screened by a series of assays. By this approach 37 putative targets were ruled out and 15 Myc target genes were uncovered. Interestingly, comparing our results with other high throughput screens reveals that certain putative Myc targets previously reported are shown not to be regulated downstream of Myc (e.g. ribosomal proteins, HSP90beta), whereas others are further supported by our analyses (e.g. pdgfbetar, nucleolin). The identity of genes specifically regulated downstream of Myc provides the critical tools required to understand the role Myc holds in the transformation process and to delineate how Myc functions as a regulator of gene transcription.


Assuntos
Regulação da Expressão Gênica , Genes myc , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Apoptose/genética , Northern Blotting , Ciclo Celular/genética , Diferenciação Celular/genética , Células Cultivadas , DNA Complementar/genética , Fibroblastos , Proteínas Nucleares/genética , Nucleofosmina , Análise de Sequência com Séries de Oligonucleotídeos , Fosfoproteínas/genética , Inibidor 1 de Ativador de Plasminogênio/genética , Proteínas/genética , Proteínas de Ligação a RNA/genética , Nucleolina
20.
Heart Lung Circ ; 11(2): 95-101, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-16352076

RESUMO

BACKGROUND: Medical outcomes following coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA) are similar, but few studies have compared neuropsychological outcomes after these procedures. METHODS: A retrospective study compared detailed neurocognitive and psychosocial functioning in 32 patients (CABG, n = 16; PTCA, n = 16) aged 61 +/- 6 years, 9-15 months after coronary revascularisation. Subjects were tested for executive functioning, speed of processing/attention and learning/memory, significant psychopathology (General Health Questionnaire, GHQ) and psychosocial functioning (Short Form (SF)-36 health survey). In the prospective study, 55 patients completed GHQ and SF-36 surveys, the day prior to and 6 months following PTCA. RESULTS: There were no significant differences between the CABG and PTCA groups for neuropsychological or psychosocial end-points (P > 0.20). Executive functioning in both groups, however, was worse than for healthy population controls (P < 0.01). The PTCA patients were significantly more likely than CABG patients to have psychiatric abnormality (GHQ Score >4; P < 0.01). After PTCA, however, there was a significant improvement in the GHQ and SF-36 scores (P < 0.05). CONCLUSIONS: Although executive function is often impaired after coronary revascularisation, neuropsychological status appears equivalent after CABG or PTCA. Psychiatric pathology is common in patients undergoing PTCA, but improves after this intervention.

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