Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
2.
Proteomics ; 22(1-2): e2100171, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34561969

RESUMO

Human leukocyte antigen (HLA) class I has more than 18,000 alleles, each of which binds to a set of unique peptides from the cellular degradome. Deciphering the interaction between antigenic peptides and HLA proteins is crucial for understanding immune responses in autoimmune diseases and cancer. In this study, we aimed to characterize the peptidome that binds to HLA-A*33:03, which is one of the most prevalent HLA-A alleles in the Northeast Asian population, but poorly studied. For this purpose, we analyzed the HLA-A*33:03 monoallelic B cell line using immunoprecipitation of HLA-A and peptide complexes, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, we identified 5731 unique peptides that were associated with HLA A*33:03, and experimentally validated the affinity of 40 peptides for HLA-A*33:03 and their stability in HLA A*33:03-peptides complexes. To our knowledge, this study represents the largest dataset of peptides associated with HLA-A*33:03. Also, this is the first study in which HLA A*33:03-associated peptides were experimentally validated.


Assuntos
Antígenos HLA-A , Espectrometria de Massas em Tandem , Cromatografia Líquida , Epitopos , Humanos , Imunoprecipitação
3.
Nature ; 534(7605): 47-54, 2016 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-27135926

RESUMO

We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer.


Assuntos
Neoplasias da Mama/genética , Genoma Humano/genética , Mutação/genética , Estudos de Coortes , Análise Mutacional de DNA , Replicação do DNA/genética , DNA de Neoplasias/genética , Feminino , Genes BRCA1 , Genes BRCA2 , Genômica , Humanos , Masculino , Mutagênese , Taxa de Mutação , Oncogenes/genética , Reparo de DNA por Recombinação/genética
4.
Mod Pathol ; 34(1): 141-160, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32709987

RESUMO

Anorectal malignant melanoma (ARMM) is a rare disease with poor prognosis. Determining ARMM prognosis precisely is difficult due to the lack of proper assessment techniques. Immunotherapy has proven effective against cutaneous malignant melanoma and may show efficacy in ARMM. Herein, we assessed the immune profile of ARMM to identify possible prognostic biomarkers. Twenty-two ARMM formalin-fixed and paraffin-embedded samples were evaluated using an nCounter® PanCancer Immune Profiling Panel. Validation was performed through immunohistochemical staining for CD3, CD8, Foxp3, CD68, CD163, and PD-L1. RNA analysis revealed significantly decreased scores for pathways involved in cell regulation and function, as well as chemokines, in recurrent patients compared to nonrecurrent patients. In cell-type profiling, the recurrent cases displayed significantly low tumor infiltrating lymphocyte (TIL) scores. Recurrence/death prediction models were defined using logistic regression and showed significantly lower scores in recurrent and deceased patients (all, P < 0.001) compared to those in nonrecurrent and surviving patients. The high total TIL and tumor-associated macrophage (TAM) groups had significantly better overall survival outcomes compared to the low total TIL and TAM groups (P = 0.007 and P = 0.035, respectively). In addition, the presence of CD3 + TILs in the invasion front was an independent favorable prognostic indicator (P = 0.003, hazard ratio = 0.21, 95% confidential interval, 0.01-0.41). Patients with inflamed or brisk-infiltration type tumors also had a significantly better overall survival than that of patients with immune-desert/excluded and absent/non-brisk type tumors (P = 0.03 and P = 0.0023, respectively). In conclusion, TILs have a strong prognostic value in ARMM, and the quantification of TILs and an analysis of the TIL phenotype and infiltration pattern during pathological diagnosis are essential to guide treatment strategies and accurate prognosis in ARMM.


Assuntos
Neoplasias do Ânus/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos do Interstício Tumoral/imunologia , Melanoma/imunologia , Microambiente Tumoral/imunologia , Macrófagos Associados a Tumor/imunologia , Idoso , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Neoplasias do Ânus/genética , Neoplasias do Ânus/mortalidade , Neoplasias do Ânus/patologia , Antígeno B7-H1/análise , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Complexo CD3/análise , Bases de Dados Factuais , Proteínas da Matriz Extracelular/análise , Feminino , Fatores de Transcrição Forkhead/análise , Humanos , Receptores de Hialuronatos/análise , Masculino , Melanoma/genética , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Fenótipo , Prognóstico , Estudos Retrospectivos
5.
J Transl Med ; 19(1): 138, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794926

RESUMO

BACKGROUND: Hepatocytes usually express fibroblast growth factor receptor 4 (FGFR4), but not its ligand, fibroblast growth factor 19 (FGF19). A subtype of hepatocellular carcinoma (HCC) expresses FGF19, which activates the FGFR4 signaling pathway that induces cell proliferation. FGFR4 inhibitors that target this mechanism are under clinical development for the treatment of HCCs with FGF19 amplification or FGFR4 overexpression. Src plays an essential role in the FGFR1 and FGFR2 signaling pathways. However, it is yet to be understood whether Src has any role in the FGF19-FGFR4 pathway in HCCs. In this study, we aimed to elucidate the role of Src in the FGF19-FGFR4 axis in HCC. METHODS: 3 HCC cell lines expressing both FGF19 and FGFR4 were selected. The expression of each protein was suppressed by siRNA treatment, and the activity-regulating relationship between FGFR4 and Src was investigated by westernblot. Co-immunoprecipitation was performed using the FGFR4 antibody to identify the endosomal complex formation and receptor endocytosis. The intracellular migration pathways of the endosomal complex were observed by immuno-fluorescence and nuclear co-immunoprecipitation. Dasatinib and BLU9931 were used for cytotoxicity comparison. RESULTS: FGFR4 modulates the activity of Src and Src modulates the expression of FGFR4, showing a mutual regulatory relationship. FGFR4 activated by FGF19 formed an endosomal complex with Src and STAT3 and moved to the nucleus. However, when Src was suppressed, the formation of the endosomal complex was not observed. FGFR4 was released from the complex transferred into the nucleus and the binding of Src and STAT3 was maintained. Dasatinib showed cytotoxic results comparable to BLU9931. The results of our study demonstrated that Src is essential for the nuclear transport of STAT3, as it induces the endosomal delivery of FGFR4 in FGF19-expressing HCC cell lines. CONCLUSIONS: We found that Src is essential for the endosomal delivery of the FGFR4 signaling complex in HCC. Our findings provide a scientific rationale for repurposing Src inhibitors for the treatment of HCCs in which the FGFR4 pathway is activated.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/tratamento farmacológico , Proliferação de Células , Fatores de Crescimento de Fibroblastos , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais
6.
Stroke ; 51(7): 2208-2218, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32521221

RESUMO

BACKGROUND AND PURPOSE: The therapeutic use of transcranial direct current stimulation (tDCS), an adjuvant tool for stroke, induces long-term changes in cortical excitability, for example, the secretion of activity-dependent growth factors. We assessed the proper therapeutic configuration of high-definition tDCS (HD-tDCS) in the subacute stage of ischemic stroke and its underlying expression profiling of growth factors to propose a new method for ensuring better therapeutic effects. METHODS: Male C57BL/6J mice were subjected to middle cerebral artery occlusion, after which repetitive HD-tDCS (20 minutes, 55 µA/mm2, charge density 66 000 C/m2) was applied from subacute phases of their ischemic insult. Behavioral tests assessing motor and cognitive functions were used to determine suitable conditions and HD-tDCS stimulation sites. Gene expression profiling of growth factors and their secretion and activation were analyzed to shed light on the underlying mechanisms. RESULTS: Anodal HD-tDCS application over the contralesional cortex, especially the motor cortex, was more effective than ipsilesional stimulation in attenuating motor and cognitive deficits. In the HD-tDCS application over the contralesional motor cortex, positive changes in Bmp8b, Gdf5, Il4, Pdgfa, Pgf, and Vegfb were observed in the ipsilesional site. The expression of GDF5 (growth/differentiation factor 5) and PDGFA (platelet-derived growth factor subunit A) tended to similarly increase in both ipsi- and contralesional striata. However, higher expression levels of GDF5 and PDGFA and their receptors were observed in the peri-infarct regions of the striatum after HD-tDCS, especially in PDGFA expression. A higher number of proliferating or newly formed neuronal cells was detected in ipsilesional sites such as the subventricular zone. CONCLUSIONS: Application of anodal HD-tDCS over the contralesional cortex may enhance beneficial recovery through the expression of growth factors, such as GDF5 and PDGFA, in the ipsilesional site. Therefore, this therapeutic configuration may be applied in the subacute stage of ischemic stroke to ameliorate neurological impairments.


Assuntos
Lateralidade Funcional/fisiologia , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Estimulação Transcraniana por Corrente Contínua , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatologia , Fator 5 de Diferenciação de Crescimento/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Fator de Crescimento Derivado de Plaquetas/biossíntese , Acidente Vascular Cerebral/metabolismo
7.
Bioinformatics ; 33(2): 266-271, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27667790

RESUMO

MOTIVATION: In this era of biological big data, data integration has become a common task and a challenge for biologists. The Resource Description Framework (RDF) was developed to enable interoperability of heterogeneous datasets. The EBI-RDF platform enables an efficient data integration of six independent biological databases using RDF technologies and shared ontologies. However, to take advantage of this platform, biologists need to be familiar with RDF technologies and SPARQL query language. To overcome this practical limitation of the EBI-RDF platform, we developed cMapper, a web-based tool that enables biologists to search the EBI-RDF databases in a gene-centric manner without a thorough knowledge of RDF and SPARQL. RESULTS: cMapper allows biologists to search data entities in the EBI-RDF platform that are connected to genes or small molecules of interest in multiple biological contexts. The input to cMapper consists of a set of genes or small molecules, and the output are data entities in six independent EBI-RDF databases connected with the given genes or small molecules in the user's query. cMapper provides output to users in the form of a graph in which nodes represent data entities and the edges represent connections between data entities and inputted set of genes or small molecules. Furthermore, users can apply filters based on database, taxonomy, organ and pathways in order to focus on a core connectivity graph of their interest. Data entities from multiple databases are differentiated based on background colors. cMapper also enables users to investigate shared connections between genes or small molecules of interest. Users can view the output graph on a web browser or download it in either GraphML or JSON formats. AVAILABILITY AND IMPLEMENTATION: cMapper is available as a web application with an integrated MySQL database. The web application was developed using Java and deployed on Tomcat server. We developed the user interface using HTML5, JQuery and the Cytoscape Graph API. cMapper can be accessed at http://cmapper.ewostech.net Readers can download the development manual from the website http://cmapper.ewostech.net/docs/cMapperDocumentation.pdf. Source Code is available at https://github.com/muhammadshoaib/cmapperContact:smahn@gachon.ac.krSupplementary information: Supplementary data are available at Bioinformatics online.


Assuntos
Bases de Dados Factuais , Proteínas/genética , Software , Ontologias Biológicas , Expressão Gênica , Genes , Humanos , Internet , Redes e Vias Metabólicas , Proteínas/química , Proteínas/metabolismo
8.
J Transl Med ; 16(1): 374, 2018 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-30593273

RESUMO

BACKGROUND: The clinical significance of fibroblast growth factor receptor 1 (FGFR1) protein expression in pancreatic cancer is largely unknown. In this study, we aimed investigate the clinical significance of FGFR1 expression in pancreatic cancer. METHODS: First, we investigated the relationship between FGFR pathway gene expression and clinicopathological data in three pancreatic cancer cohorts containing 313 cases. Subsequently, to confirm the findings from the discovery cohorts, we performed immunohistochemistry (IHC) of FGFR1 protein in a validation cohort of 205 pancreatic cancer cases. RESULTS: In discovery cohort 1, FGFR1 and Klotho beta (KLB) overexpression was associated with low tumor stage (P < 0.05), low tumor grade (P < 0.05), and better overall survival. Multivariate analysis predicted FGFR1 (P < 0.05) as a prognostic factor for better overall survival. In discovery cohorts 2 and 3, only FGFR1 overexpression was associated with better overall survival (P < 0.05). In the validation cohort, there were 15.7% and 61% strong and weak/moderate FGFR1-positive cases, respectively. FGFR1-positive cases showed better overall survival than FGFR1-negative cases (P < 0.05). Furthermore, multivariate analysis revealed FGFR1 positivity as an independent prognostic factor for better overall survival in pancreatic cancer patients (hazard ratio 0.677, 95% confidence interval 0.471-0.972, P = 0.035). CONCLUSIONS: FGFR1 expression, as estimated by IHC, may be used to define clinically distinct subtypes in pancreatic cancer. Moreover, FGFR1-based subclassification of pancreatic cancer may lead to new therapeutic approaches for the FGFR1-positive subtype.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pancreáticas/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Estudos de Coortes , Estudos de Associação Genética , Humanos , Estimativa de Kaplan-Meier , Análise Multivariada , Modelos de Riscos Proporcionais , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Reprodutibilidade dos Testes
9.
BMC Cancer ; 18(1): 571, 2018 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-29776391

RESUMO

BACKGROUND: Efforts have been made to classify Hepatocellular Carcinoma (HCC) at surgically curable stages because molecular classification, which is prognostically informative, can accurately identify patients in need of additional early therapeutic interventions. Recently, HCC classification based French studies on the expression of 16 genes and 5 genes were proposed. In 16-gene classification, transcriptomic signatures (G1-G6) were used to classify HCC patients into clinical, genomic and pathway-specific subgroups. In 5-gene score classification, the good or poor prognosis of HCC patients was predicted. The patient's cohort in these studies was mainly from Caucasian and African populations. Here, we aimed to validate G1-G6 and 5-gene score signatures in 205 Korean HCC patients since genomic profiles of Korean patients are distinct from other regions. METHODS: Integrated analyses using whole-exome sequencing, copy number variation and clinical data was performed against these two signatures to find statistical correlations. Kaplan-Meier, univariate and multivariate COX regression analysis were performed for Disease-Specific Survival (DSS) and Recurrence-Free Survival (RFS). RESULTS: The G2 and G3 subgroups of transcriptomic signature were significantly associated with TP53 mutations while G5 and G6 subgroups were significantly associated with CTNNB1 mutations which is in concordance with original French studies. Similarly, the poor prognosis group of 5-gene score showed shorter DSS (p = 0.045) and early RFS (p = 0.023) as well as a significant association with microvascular invasion, tumor size (> 5 cm), elevated AFP levels, and RB1 mutations. However, the 5-gene score was not an independent prognostic factor for survival. CONCLUSION: The G1-G6 and 5-gene signatures showed significant concordance between genetic profiles of Korean HCC patients and patients in original French studies. Thus, G1-G6 and 5-gene score signatures can be targeted as potential therapeutic biomarkers against HCC patients worldwide.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Adulto , Idoso , Carcinoma Hepatocelular/classificação , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Estudos de Coortes , Variações do Número de Cópias de DNA/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Fígado/patologia , Neoplasias Hepáticas/classificação , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Pessoa de Meia-Idade , Mutação , Prognóstico , República da Coreia/epidemiologia , Análise de Sobrevida , Transcriptoma/genética , Sequenciamento do Exoma
10.
Lancet Oncol ; 17(9): 1261-71, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27498913

RESUMO

BACKGROUND: Sarcomas are rare, phenotypically heterogeneous cancers that disproportionately affect the young. Outside rare syndromes, the nature, extent, and clinical significance of their genetic origins are not known. We aimed to investigate the genetic basis for bone and soft-tissue sarcoma seen in routine clinical practice. METHODS: In this genetic study, we included 1162 patients with sarcoma from four cohorts (the International Sarcoma Kindred Study [ISKS], 966 probands; Project GENESIS, 48 probands; Asan Bio-Resource Center, 138 probands; and kConFab, ten probands), who were older than 15 years at the time of consent and had a histologically confirmed diagnosis of sarcoma, recruited from specialist sarcoma clinics without regard to family history. Detailed clinical, pathological, and pedigree information was collected, and cancer diagnoses in probands and relatives were independently verified. Targeted exon sequencing using blood (n=1114) or saliva (n=48) samples was done on 72 genes (selected due to associations with increased cancer risk) and rare variants were stratified into classes approximating the International Agency for Research on Cancer (IARC) clinical classification for genetic variation. We did a case-control rare variant burden analysis using 6545 Caucasian controls included from three cohorts (ISKS, 235 controls; LifePool, 2010 controls; and National Heart, Lung, and Blood Institute Exome Sequencing Project [ESP], 4300 controls). FINDINGS: The median age at cancer diagnosis in 1162 sarcoma probands was 46 years (IQR 29-58), 170 (15%) of 1162 probands had multiple primary cancers, and 155 (17%) of 911 families with informative pedigrees fitted recognisable cancer syndromes. Using a case-control rare variant burden analysis, 638 (55%) of 1162 sarcoma probands bore an excess of pathogenic germline variants (combined odds ratio [OR] 1·43, 95% CI 1·24-1·64, p<0·0001), with 227 known or expected pathogenic variants occurring in 217 individuals. All classes of pathogenic variants (known, expected, or predicted) were associated with earlier age of cancer onset. In addition to TP53, ATM, ATR, and BRCA2, an unexpected excess of functionally pathogenic variants was seen in ERCC2. Probands were more likely than controls to have multiple pathogenic variants compared with the combined control cohort group and the LifePool control cohort (OR 2·22, 95% CI 1·57-3·14, p=1·2 × 10(-6)) and the cumulative burden of multiple variants correlated with earlier age at cancer diagnosis (Mantel-Cox log-rank test for trend, p=0·0032). 66 of 1162 probands carried notifiable variants following expert clinical review (those recognised to be clinically significant to health and about which patients should be advised), whereas 293 (25%) probands carried variants with potential therapeutic significance. INTERPRETATION: About half of patients with sarcoma have putatively pathogenic monogenic and polygenic variation in known and novel cancer genes, with implications for risk management and treatment. FUNDING: Rainbows for Kate Foundation, Johanna Sewell Research Foundation, Australian National Health and Medical Research Council, Cancer Australia, Sarcoma UK, National Cancer Institute, Liddy Shriver Sarcoma Initiative.


Assuntos
Biomarcadores Tumorais/genética , Exoma/genética , Mutação/genética , Saliva/química , Sarcoma/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Seguimentos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Lactente , Recém-Nascido , Agências Internacionais , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Linhagem , Prognóstico , Fatores de Risco , Sarcoma/sangue , Adulto Jovem
11.
Biochem Biophys Res Commun ; 477(4): 1038-1044, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27395339

RESUMO

Transforming growth factor-ß1 (TGF-ß1), a potent inducer of epithelial-to-mesenchymal transition (EMT), upregulates the cold-inducible RNA-binding protein (CIRP). The link between CIRP and EMT, however, remains unknown. To determine the role of CIRP in EMT, we performed CIRP knockdown and overexpression experiments in in vitro TGF-ß1-induced EMT models. We found that CIRP overexpression promoted the downregulation of epithelial markers and the upregulation of mesenchymal markers after TGF-ß1 treatment for EMT induction. It also promoted cell migration and invasion, key features of EMT. In contrast, CIRP knockdown inhibited the downregulation of epithelial markers and the upregulation of mesenchymal markers after TGF-ß1 treatment for EMT induction. In addition, it also inhibited cell migration and invasion. Furthermore, we demonstrated that the RNA-recognition motif in CIRP is essential for the role of CIRP in EMT. At the downstream level, CIRP knockdown downregulated Snail, key transcriptional regulator of EMT, while CIRP overexpression upregulated it. We found out that the link between CIRP and Snail is mediated by ERK and p38 pathways. EMT is a critical component of carcinoma metastasis and invasion. As demonstrated in this study, the biological role of CIRP in EMT may explain why CIRP overexpression has been associated with a bad prognosis in cancer patients.


Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Metástase Neoplásica/patologia , Metástase Neoplásica/fisiopatologia , Proteínas de Ligação a RNA/metabolismo , Células A549 , Movimento Celular , Ativação Enzimática , Humanos , Invasividade Neoplásica , Regulação para Cima/fisiologia
12.
J Neurochem ; 135(3): 577-88, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26285165

RESUMO

To evaluate the question of whether protease activated receptor-1 (PAR-1) antagonist is a potential therapeutic target in multiple sclerosis, we treated experimental autoimmune encephalomyelitis (EAE) mice with two PAR-1 antagonists, KC-A0590 and SCH-530348. Treatment with both antagonists resulted in a significant decrease in the clinical characteristics of EAE mice by suppressing demyelination and infiltration of inflammatory cells in the spinal cord and brain, as well as a significantly reducing the increased thrombin and tumor necrosis factor-α. Profound leakage of dextran was observed in the brain of EAE mice. However, treatment with PAR-1 antagonists resulted in the stabilization of vascular endothelial cells and reduced blood-brain barrier breakdown with suppression of inflammatory response. Treatment with PAR-1 antagonists also resulted in down-regulated expression of matrix metalloproteinase-9 and preserved expression of occludin and zonula occludens (ZO)-1 in the brain and their significant expression was confirmed in neurons, astrocytes, and vascular endothelial cells. Finally, endothelial cells and primary cultured astrocytes were treated with PAR-1 antagonists; both antagonists suppressed thrombin-induced breakdown of ZO-1 in endothelial cells and secretion of matrix metalloproteinase-9 in astrocytes. Collectively, our results suggest that PAR-1 antagonist is effective in attenuation of the clinical symptoms of EAE mice by stabilizing the blood-brain barrier and may have therapeutic potential for treatment of multiple sclerosis.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/patologia , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/patologia , Lactonas/uso terapêutico , Piridinas/uso terapêutico , Receptor PAR-1/antagonistas & inibidores , Animais , Feminino , Lactonas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Piridinas/farmacologia
13.
Biochem Biophys Res Commun ; 464(3): 916-21, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26188505

RESUMO

CIRP has been implicated in apoptosis, yet its mechanism of action remains unknown. To determine the role of CIRP in DNA damage-induced apoptosis, we performed CIRP overexpression and knockdown experiments to investigate the effects of CIRP on key molecules in apoptosis pathway. Etoposide treatment was used to induce DNA damage-induced apoptosis. We found that CIRP knockdown increased p53 level, which in turn up-regulated pro-apoptotic genes and down-regulated anti-apoptotic genes. In contrast, CIRP overexpression decreased p53 level, which in turn down-regulated pro-apoptotic genes and up-regulated anti-apoptotic genes. The change in the expression levels of pro-apoptotic and anti-apoptotic genes shifts the balance between life and death of cells. CIRP expression is upregulated by chronic inflammation, and this phenomenon provides an interesting interventional opportunity in cancers arising from chronic inflammation. Chronic inflammation up-regulates CIRP, which in turn inhibit apoptosis. Therefore, inhibiting the function of up-regulated CIRP may have a therapeutic value in cancer.


Assuntos
Apoptose/genética , Dano ao DNA/fisiologia , Proteínas de Ligação a RNA/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Caspase 3 , Dano ao DNA/efeitos dos fármacos , Etoposídeo/farmacologia , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Células Hep G2/efeitos dos fármacos , Humanos , Proteínas Inibidoras de Apoptose/genética , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas de Ligação a RNA/genética , Regulação para Cima
14.
Hepatology ; 60(6): 1972-82, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24798001

RESUMO

UNLABELLED: Hepatic resection is the most curative treatment option for early-stage hepatocellular carcinoma, but is associated with a high recurrence rate, which exceeds 50% at 5 years after surgery. Understanding the genetic basis of hepatocellular carcinoma at surgically curable stages may enable the identification of new molecular biomarkers that accurately identify patients in need of additional early therapeutic interventions. Whole exome sequencing and copy number analysis was performed on 231 hepatocellular carcinomas (72% with hepatitis B viral infection) that were classified as early-stage hepatocellular carcinomas, candidates for surgical resection. Recurrent mutations were validated by Sanger sequencing. Unsupervised genomic analyses identified an association between specific genetic aberrations and postoperative clinical outcomes. Recurrent somatic mutations were identified in nine genes, including TP53, CTNNB1, AXIN1, RPS6KA3, and RB1. Recurrent homozygous deletions in FAM123A, RB1, and CDKN2A, and high-copy amplifications in MYC, RSPO2, CCND1, and FGF19 were detected. Pathway analyses of these genes revealed aberrations in the p53, Wnt, PIK3/Ras, cell cycle, and chromatin remodeling pathways. RB1 mutations were significantly associated with cancer-specific and recurrence-free survival after resection (multivariate P = 0.038 and P = 0.012, respectively). FGF19 amplifications, known to activate Wnt signaling, were mutually exclusive with CTNNB1 and AXIN1 mutations, and significantly associated with cirrhosis (P = 0.017). CONCLUSION: RB1 mutations can be used as a prognostic molecular biomarker for resectable hepatocellular carcinoma. Further study is required to investigate the potential role of FGF19 amplification in driving hepatocarcinogenesis in patients with liver cirrhosis and to investigate the potential of anti-FGF19 treatment in these patients.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/genética , Fatores de Crescimento de Fibroblastos/genética , Neoplasias Hepáticas/genética , Proteína do Retinoblastoma/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/cirurgia , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Fator de Transcrição E2F1/metabolismo , Feminino , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Proteína do Retinoblastoma/metabolismo
15.
Nature ; 458(7239): 740-2, 2009 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-19360082

RESUMO

Despite the complexity and diversity of nature, there exists universality in the form of critical scaling laws among various dissimilar systems and processes such as stock markets, earthquakes, crackling noise, lung inflation and vortices in superconductors. This universality is mainly independent of the microscopic details, depending only on the symmetry and dimension of the system. Exploring how universality is affected by the system dimensions is an important unresolved problem. Here we demonstrate experimentally that universality persists even at a dimensionality crossover in ferromagnetic nanowires. As the wire width decreases, the magnetic domain wall dynamics changes from elastic creep in two dimensions to a particle-like stochastic behaviour in one dimension. Applying finite-size scaling, we find that all our experimental data in one and two dimensions (including the crossover regime) collapse onto a single curve, signalling universality at the criticality transition. The crossover to the one-dimensional regime occurs at a few hundred nanometres, corresponding to the integration scale for modern nanodevices.

16.
BMC Complement Altern Med ; 15: 202, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26122524

RESUMO

BACKGROUND: Four traditional Korean medicinal herbs which act in retarding the aging process, Polygonum multiflorum Thunb., Rehmannia glutinosa (Gaertn) Libosch., Polygala tenuifolia Willd., and Acorus gramineus Soland., were prepared by systematic investigation of Dongeuibogam (Treasured Mirror of Eastern Medicine), published in the early 17th century in Korea. This study was performed to evaluate beneficial effects of four herbal mixture extract (PMC-12) on hippocampal neuron and spatial memory. METHODS: High performance liquid chromatography (HPLC) analysis was performed for standardization of PMC-12. Cell viability, lactate dehydrogenase, flow cytometry, reactive oxygen species (ROS), and Western blot assays were performed in HT22 hippocampal cells and immunohistochemistry and behavioral tests were performed in a mouse model of focal cerebral ischemia in order to observe alterations of hippocampal cell survival and subsequent memory function. RESULTS: In the HPLC analysis, PMC-12 was standardized to contain 3.09% 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside, 0.35% 3',6-disinapoyl sucrose, and 0.79% catalpol. In HT22 cells, pretreatment with PMC-12 resulted in significantly reduced glutamate-induced apoptotic cell death. Pretreatment with PMC-12 also resulted in suppression of ROS accumulation in connection with cellular Ca(2+) level after exposure to glutamate. Expression levels of phosphorylated p38 mitogen-activated protein kinases (MAPK) and dephosphorylated phosphatidylinositol-3 kinase (PI3K) by glutamate exposure were recovered by pretreatment with either PMC-12 or anti-oxidant N-acetyl-L-cysteine (NAC). Expression levels of mature brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (CREB) were significantly enhanced by treatment with either PMC-12 or NAC. Combination treatment with PMC-12, NAC, and intracellular Ca(2+) inhibitor BAPTA showed similar expression levels. In a mouse model of focal cerebral ischemia, we observed higher expression of mature BDNF and phosphorylation of CREB in the hippocampus and further confirmed improved spatial memory by treatment with PMC-12. CONCLUSIONS: Our results suggest that PMC-12 mainly exerted protective effects on hippocampal neurons through suppression of Ca(2+)-related ROS accumulation and regulation of signaling pathways of p38 MAPK and PI3K associated with mature BDNF expression and CREB phosphorylation and subsequently enhanced spatial memory.


Assuntos
Isquemia Encefálica/metabolismo , Hipocampo/citologia , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Memória Espacial/efeitos dos fármacos , Animais , Linhagem Celular , Modelos Animais de Doenças , Camundongos
17.
Nat Mater ; 12(7): 611-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23770726

RESUMO

In most ferromagnets the magnetization rotates from one domain to the next with no preferred handedness. However, broken inversion symmetry can lift the chiral degeneracy, leading to topologically rich spin textures such as spin spirals and skyrmions through the Dzyaloshinskii-Moriya interaction (DMI). Here we show that in ultrathin metallic ferromagnets sandwiched between a heavy metal and an oxide, the DMI stabilizes chiral domain walls (DWs) whose spin texture enables extremely efficient current-driven motion. We show that spin torque from the spin Hall effect drives DWs in opposite directions in Pt/CoFe/MgO and Ta/CoFe/MgO, which can be explained only if the DWs assume a Néel configuration with left-handed chirality. We directly confirm the DW chirality and rigidity by examining current-driven DW dynamics with magnetic fields applied perpendicular and parallel to the spin spiral. This work resolves the origin of controversial experimental results and highlights a new path towards interfacial design of spintronic devices.

18.
J Clin Gastroenterol ; 47(7): 644-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23442843

RESUMO

BACKGROUND: Genetic variations in interleukin 28B (IL28B) have been strongly associated with a sustained virological response (SVR) in European and African-American patients. Genetic variation of IL28B was investigated in healthy controls and chronic hepatitis C (CHC) patients, and the treatment response in the CHC patients was analyzed according to IL28B polymorphism in the Korean population. METHODS: IL28B polymorphisms (rs12979860 and rs8099917) were studied in 200 healthy controls and in 167 CHC patients who were treated with peginterferon-α and ribavirin. RESULTS: The prevalence of rs12979860 in healthy controls is as follows: the CC-genotype was 88.5%, the CT-genotype was 11.5%, and the TT-genotype was not found. The prevalence of rs8099917 in healthy controls is as follows: the TT-genotype was 89.5%, the TG-genotype was 10.5%, and the GG-genotype was not found. The CC-genotype of rs12979860 and the TT-genotype of rs8099917 were found to be closely related (linkage disequilibrium; D'=1.0, χ =0.9082). In 106 CHC patients treated with peginterferon and ribavirin, the SVR was 67.2% (n=58) for 1b, 91.6% (n=47) for 2a. In hepatitis C virus (HCV) genotype 1b with respect to rs12979860, the SVR in CC-genotype was 72.9% and that in CT-genotype was 40.0%. On investigating predictive factors for SVR, pretreatment low-HCV RNA levels, HCV genotype non-1, early virological response, and also the IL28B CC-genotype for rs12979860 were good indicators of an SVR. CONCLUSIONS: In Korea, genetic variation of IL28B is different from that in western countries in view of high prevalence of rs12979860 CC-genotype. It seems likely that a high SVR in Korean patients with genotype 1 CHC patients is due to the genetic polymorphism in IL28B.


Assuntos
Antivirais/uso terapêutico , Povo Asiático/genética , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/genética , Interleucinas/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Estudos de Casos e Controles , Primers do DNA/química , Quimioterapia Combinada , Feminino , Genótipo , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Humanos , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Interferons , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/uso terapêutico , Reação em Cadeia da Polimerase , Prevalência , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Ribavirina/uso terapêutico , Carga Viral/efeitos dos fármacos
19.
Nanotechnology ; 24(10): 105304, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23416725

RESUMO

We investigate a control scheme for enhancing the controllability of domain-wall (DW) pinning on ferromagnetic devices using an interaction between magnetic charges distributed on a nanobar and at a notch, respectively. The scheme is realized at an artificial notch with a nanobar vertical to it on Permalloy nanowires with an asymmetrical pad. Injection fields for injecting the DWs from the asymmetrical pad to the nanowire show an asymmetrical dependence on the saturation angle for initializing the magnetization of the nanowire, and the injected DWs are pinned by the notch with the nanobar vertical to it. We have found that the landscape of the pinning potential energy experienced by the DWs depends on the magnetized direction of the nanobar and that its level is shifted by the injection field, leading to an increase or decrease in the depinning field with respect to the saturation angle. This is consistent with our estimation based on micromagnetic simulation.

20.
J Nanosci Nanotechnol ; 13(11): 7291-4, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24245245

RESUMO

Sensitive and accurate DNA quantification is an essential step in most DNA analyses, especially in analysis of a small amount of DNA. Instead of typical DNA quantification methods (i.e., UV spectrometry, fluorometry, and quantitative polymerase chain reaction), electrical impedance spectroscopy has recently been investigated for label-free and efficient quantification of DNA. In this study, quantification of DNA in solution was investigated using electrical impedance spectroscopy without pre-processing, including the modification of the electrode surface and immobilization of DNA onto the electrode. The results showed that the measured impedance spectra were in agreement with a designed equivalent circuit model, and that the extrapolated parameters of interfacial electrode impedance were dependent on DNA concentration. The impedance measured at 1 and 10 kHz showed good correlation with DNA concentration (R2 > 0.95), with a dynamic range of detection from 0.01 pg/microl to 100 ng/microl. Based on the results, it is expected to utilize impedance spectroscopy for the real-time and label-free characterization of DNA concentration with high sensitivity and low operation cost.


Assuntos
DNA/química , DNA/genética , Espectroscopia Dielétrica/instrumentação , Eletrodos , Microquímica/instrumentação , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , DNA/análise , Espectroscopia Dielétrica/métodos , Impedância Elétrica , Desenho de Equipamento , Análise de Falha de Equipamento , Microquímica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA