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1.
Biochem Cell Biol ; 101(4): 326-360, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37040564

RESUMO

Graduate students are vital to the creation of research and innovation in Canada. The National Graduate Student Finance Survey was launched in 2021 by the Ottawa Science Policy Network to investigate the financial realities of Canadian graduate students. Closing in April 2022, the survey received 1305 responses from graduate students representing various geographical locations, years of study, fields of education, and demographic backgrounds. The results capture a snapshot into graduate student finances, including an in-depth analysis of stipends, scholarships, debt, tuition, and living expenses. In its entirety, we found that the majority of graduate students are facing serious financial concerns. This is largely due to stagnant funding for students both from federal and provincial granting agencies and from within their institutions. This reality is even worse for international students, members of historically underrepresented communities, and those with dependents, all of whom experience additional challenges that impact their financial security. Based on our findings, we propose several recommendations to the Tri-Council agencies (Natural Sciences and Engineering Research Council, Social Science and Humanities Research Council, and Canadian Institute for Health Research) and academic institutions to strengthen graduate student finances and help sustain the future of research in Canada.


Assuntos
Estresse Financeiro , Estudantes , Humanos , Canadá
2.
Arterioscler Thromb Vasc Biol ; 41(8): 2252-2262, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34134519

RESUMO

OBJECTIVE: Leveraging microRNA-Seq data and the 1000 Genomes imputed genotypes, we identified rs174561 as a strong microRNA quantitative trait loci for circulating microRNA-1908-5p with higher miR-1908-5p and reduced LDL (lowdensity lipoprotein)-cholesterol, fasting glucose and A1c concentrations in carriers of the rs-174561-C allele. Here, we have investigated the molecular mechanism(s) linking miR-1908-5p to LDL-C concentrations. APPROACH AND RESULTS: Transfection experiments demonstrate that the presence of the C allele significantly increases miR- 1908-5p abundance relative to the T allele. LDLR mRNA and low-density lipoprotein receptor (LDLR) total protein were unchanged in response to differential miR-1908-5p expression. However, the ratio of the cleaved to full-length form of LDLR decreased with miR-1908-5p mimic and increased with miR-1908-5p inhibitor treatment. BMP1 (bone morphogenetic protein 1) is a protease responsible for LDLR cleavage, and we show that miR-1908-5p mimic reduces BMP1 mRNA. Using a reporter array, we identified the TGF-ß (transforming growth factor-beta) signaling pathway activity to be reduced by miR- 1908-5p mimic treatment, and this was associated with reduced TGFB1 expression. TGF-ß signaling increases BMP1, and we further demonstrate that the effect of miR-1908-5p on LDLR cleavage is abolished by exogenous TGF-ß treatment. CONCLUSIONS: These findings uncover a mechanism whereby miR-1908-5p reduces TGFB1 abundance resulting in lower expression of BMP1, ultimately leading to reduced LDLR cleavage. Cleavage of the mature LDLR is known to reduce cell surface affinity for LDL, thereby linking miR-1908-5p to lower circulating LDL-cholesterol levels.


Assuntos
Proteína Morfogenética Óssea 1/metabolismo , LDL-Colesterol/metabolismo , Ácidos Graxos Dessaturases/genética , Hepatócitos/enzimologia , MicroRNAs/metabolismo , Polimorfismo Genético , Proteína Morfogenética Óssea 1/genética , Linhagem Celular , Dessaturase de Ácido Graxo Delta-5 , Ácidos Graxos Dessaturases/metabolismo , Regulação da Expressão Gênica , Humanos , MicroRNAs/genética , Estabilidade Proteica , Proteólise , Estabilidade de RNA , Receptores de LDL/genética , Receptores de LDL/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
3.
Fetal Pediatr Pathol ; 41(4): 558-567, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33295826

RESUMO

IntroductionVE1 is a monoclonal antibody detecting mutant BRAF V600E protein by immunohistochemistry (IHC) with a high concordance rate with molecular analysis in many cancers. Materials and methods: BRAF V600E mutation was assessed on 94 pediatric LCH patients using sequencing analysis and VE1 immunohistochemistry with stringent and lenient-scoring criteria. Results: BRAF V600E mutation exon 15 was detected by sequencing in 47.9% of LCH cases. BRAF V600E mutation rate in multiple-system LCH was 65.2%, significantly higher than in single-system LCH (p = .001). VE1 assays showed 35.6% sensitivity, 75.5% specificity (Stringent criteria), and 91.1% sensitivity, 35.7% specificity (Lenient criteria). Conclusions: The proportion of BRAF V600E mutational status was relatively high and related to high-risk LCH. Molecular assays for BRAF mutation detection are preferred in LCH lesions. VE1 is not ready as an alternative option for LCH BRAF testing.


Assuntos
Histiocitose de Células de Langerhans , Proteínas Proto-Oncogênicas B-raf , Anticorpos Monoclonais , Criança , Histiocitose de Células de Langerhans/diagnóstico , Histiocitose de Células de Langerhans/genética , Humanos , Imuno-Histoquímica , Mutação , Proteínas Proto-Oncogênicas B-raf/análise , Proteínas Proto-Oncogênicas B-raf/genética
4.
Clin Infect Dis ; 70(5): 827-834, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-30944929

RESUMO

BACKGROUND: Pretreatment predictors of death from tuberculous meningitis (TBM) are well established, but whether outcome can be predicted more accurately after the start of treatment by updated clinical variables is unknown. Hence, we developed and validated models that dynamically predict mortality using time-updated Glasgow Coma Scale (GCS) and plasma sodium measurements, together with patient baseline characteristics. METHODS: We included 1048 adults from 4 TBM studies conducted in southern Vietnam from 2004 to 2016. We used a landmarking approach to predict death within 120 days after treatment initiation using time-updated data during the first 30 days of treatment. Separate models were built for patients with and without human immunodeficiency virus (HIV) infection. We used the area under the receiver operating characteristic curve (AUC) to evaluate performance of the models at days 10, 20, and 30 of treatment to predict mortality by 60, 90, and 120 days. Our internal validation was corrected for overoptimism using bootstrap. We provide a web-based application that computes mortality risk within 120 days. RESULTS: Higher GCS indicated better prognosis in all patients. In HIV-infected patients, higher plasma sodium was uniformly associated with good prognosis, whereas in HIV-uninfected patients the association was heterogeneous over time. The bias-corrected AUC of the models ranged from 0.82 to 0.92 and 0.81 to 0.85 in HIV-uninfected and HIV-infected individuals, respectively. The models outperformed the previously published baseline models. CONCLUSIONS: Time-updated GCS and plasma sodium measurements improved predictions based solely on information obtained at diagnosis. Our models may be used in practice to define those with poor prognosis during treatment.


Assuntos
Tuberculose Meníngea , Adulto , Escala de Coma de Glasgow , Humanos , Plasma , Prognóstico , Sódio , Tuberculose Meníngea/diagnóstico , Vietnã
5.
J Biol Chem ; 289(7): 4273-85, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24391090

RESUMO

Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated.


Assuntos
Anticorpos Monoclonais Murinos/toxicidade , Anticorpos Neutralizantes/toxicidade , Autoanticorpos/toxicidade , Displasia Ectodérmica/induzido quimicamente , Displasia Ectodérmica/imunologia , Ectodisplasinas/antagonistas & inibidores , Animais , Anticorpos Monoclonais Murinos/genética , Anticorpos Monoclonais Murinos/imunologia , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/imunologia , Autoanticorpos/genética , Autoanticorpos/imunologia , Sequência de Bases , Bovinos , Linhagem Celular , Cães , Displasia Ectodérmica/genética , Displasia Ectodérmica/metabolismo , Displasia Ectodérmica/patologia , Ectodisplasinas/genética , Ectodisplasinas/imunologia , Ectodisplasinas/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , Gravidez
6.
J Clin Tuberc Other Mycobact Dis ; 35: 100431, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38523706

RESUMO

Objective: We conducted a descriptive analysis of multi-drug resistant tuberculosis (MDR-TB) in Vietnam's two largest cities, Hanoi and Ho Chi Minh city. Methods: All patients with rifampicin resistant tuberculosis were recruited from Hanoi and surrounding provinces between 2020 and 2022. Additional patients were recruited from Ho Chi Minh city over the same time period. Demographic data were recorded from all patients, and samples collected, cultured, whole genome sequenced and analysed for drug resistance mutations. Genomic susceptibility predictions were made on the basis of the World Health Organization's catalogue of mutations in Mycobacterium tuberculosis associated with drug resistance, version 2. Comparisons were made against phenotypic drug susceptibility test results where these were available. Multivariable logistic regression was used to assess risk factors for previous episodes of tuberculosis. Results: 233/265 sequenced isolates were of sufficient quality for analysis, 146 (63 %) from Ho Chi Minh City and 87 (37 %) from Hanoi. 198 (85 %) were lineage 2, 20 (9 %) were lineage 4, and 15 (6 %) were lineage 1. 17/211 (8 %) for whom HIV status was known were infected, and 109/214 (51 %) patients had had a previous episode of tuberculosis. The main risk factor for a previous episode was HIV infection (odds ratio 5.1 (95 % confidence interval 1.3-20.0); p = 0.021). Sensitivity for predicting first-line drug resistance from whole genome sequencing data was over 90 %, with the exception of pyrazinamide (85 %). For moxifloxacin and amikacin it was 50 % or less. Among rifampicin-resistant isolates, prevalence of resistance to each non-first-line drug was < 20 %. Conclusions: Drug resistance among most MDR-TB strains in Vietnam's two largest cities is confined largely to first-line drugs. Living with HIV is the main risk factor among patients with MDR-TB for having had a previous episode of tuberculosis.

7.
Mucosal Immunol ; 16(4): 476-485, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37178819

RESUMO

Short-chain fatty acids (SCFAs) are metabolites that are produced after microbial fermentation of dietary fiber and impact cell metabolism and anti-inflammatory pathways both locally in the gut and systemically. In preclinical models, administration of SCFAs, such as butyrate, ameliorates a range of inflammatory disease models including allergic airway inflammation, atopic dermatitis, and influenza infection. Here we report the effect of butyrate on a bacteria-induced acute neutrophil-driven immune response in the airways. Butyrate impacted discrete aspects of hematopoiesis in the bone marrow resulting in the accumulation of immature neutrophils. During Pseudomonas aeruginosa infection, butyrate treatment led to the enhanced mobilization of neutrophils to the lungs as a result of increased CXCL2 expression by lung macrophages. Despite this increase in granulocyte numbers and their enhanced phagocytic capacity, neutrophils failed to control early bacterial growth. Butyrate reduced the expression of nicotinamide adenine dinucleotide phosphate, oxidase complex components required for reactive oxygen species production, and reduced secondary granule enzymes, culminating in impaired bactericidal activity. These data reveal that SCFAs tune neutrophil maturation and effector function in the bone marrow under homeostatic conditions, potentially to mitigate against excessive granulocyte-driven immunopathology, but their consequently restricted bactericidal capacity impairs early control of Pseudomonas infection.


Assuntos
Anti-Infecciosos , Butiratos , Humanos , Butiratos/farmacologia , Butiratos/metabolismo , Neutrófilos , Ácidos Graxos Voláteis/metabolismo , Pulmão/patologia , Inflamação/metabolismo , Homeostase , Anti-Infecciosos/metabolismo
8.
Org Biomol Chem ; 10(41): 8348-60, 2012 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-22996034

RESUMO

The cell wall phosphomannan of Candida species is a complex N-linked glycoprotein with a glycan chain containing predominantly an α-linked mannose backbone with α-mannose branches. A minor ß-mannan component is attached to the branches either via a glycosidic bond (acid stable ß-mannan) or a phosphodiester bond (acid-labile ß-mannan). The α-mannan residues of the cell wall phosphomannan do not afford protective antibody, while the ß-mannan portion is a protective antigen and has become an attractive target as the key epitope of a conjugate vaccine. We report the first synthesis of a tetrasaccharide 1 consisting of a ß1,2-mannopyranosyl trisaccharide linked via a phosphodiester to methyl α-mannopyranoside. This encompasses the attachment site of the acid labile ß-mannan to the α-mannan component of the cell wall phosphomannan. The trisaccharide was formed by an iterative process to first create a ß-glucopyranoside linkage and then epimerize the C-2 center via an oxidation-reduction sequence. The phosphate diester linkage was accessed via an anomeric H-phosphonate. The binding of phosphomannan fragment 1 with the protective antibody C3.1 has been evaluated and compared with a ß-mannotrioside in hapten inhibition experiments. The observed activities are rationalized with a model for docked in the binding site of C3.1.


Assuntos
Candida albicans/química , Mananas/química , Oligonucleotídeos/química , Polissacarídeos/síntese química , Sequência de Carboidratos , Epitopos/química , Dados de Sequência Molecular , Estrutura Molecular , Polissacarídeos/química
9.
Circ Genom Precis Med ; 15(2): e003428, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35130031

RESUMO

BACKGROUND: Fibronectin (FN1) is an essential regulator of homodynamic processes and tissue remodeling that have been proposed to contribute to atherosclerosis. Moreover, recent large-scale genome-wide association studies (GWAS) have linked common genetic variants within the FN1 gene to coronary artery disease risk. METHODS: Public databases were analyzed by 2-Sample Mendelian Randomization. Expression constructs encoding short FN1 reporter constructs and full-length plasma FN1 variants were introduced in various cell models. Secreted and cellular levels were then analyzed and quantified by SDS-PAGE and fluorescence microscopy. Mass spectrometry and glycosylation analyses were performed to probe possible posttranscriptional differences. RESULTS: Bioinformatic analyses revealed that common coronary artery disease risk single nucleotide polymorphisms in the FN1 locus associate with circulating levels of FN1 and that higher FN1 (fibronectin 1) protein levels in plasma are linked to lower coronary artery disease risk. The coronary artery disease-associated FN1 locus encompasses a common polymorphism that translates a L15Q variant situated within the FN1 signal peptide. Introduction of FN1 reporter constructs, differing at position 15, revealed differences in secretion, with the FN1 Q15 variant being less well secreted. Moreover, the L15Q polymorphism was found to alter glycosylation in some cell models but not in human plasma. CONCLUSIONS: In addition to providing novel functional evidence implicating FN1 in cardioprotection, these findings demonstrate that a common variant within a secretion signal peptide regulates protein function.


Assuntos
Doenças Cardiovasculares , Doença da Artéria Coronariana , Doenças Cardiovasculares/genética , Doença da Artéria Coronariana/genética , Fibronectinas/genética , Estudo de Associação Genômica Ampla , Humanos , Sinais Direcionadores de Proteínas/genética
10.
Atherosclerosis ; 348: 8-15, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35381443

RESUMO

BACKGROUND AND AIMS: Genome-wide association studies (GWAS) identified a coronary artery disease (CAD) risk locus on 13.q34 tagged by rs61969072 (T/G). This variant lies in an intergenic region, proximal to ING1, CARKD and CARS2 but its causal relationship to CAD is unknown. METHODS AND RESULTS: We first demonstrated that rs61969072 and tightly linked single nucleotide polymorphisms (SNPs) associate with CARS2 but not ING1 or CARKD expression in carotid endarterectomy samples, with reduced CARS2 abundance in carriers of the CAD risk allele (G). THP-1 monocytes were differentiated and polarized to proinflammatory (M1) and anti-inflammatory (M2) macrophages. CARS2 gene expression decreased in M1 and increased in M2 macrophages, consistent with a role for CARS2 in inflammation. Gene expression profiling revealed an increase in pro-inflammatory markers in response to CARS2 siRNA knockdown in THP-1 derived macrophages, accompanied by an increased abundance of inflammatory cytokines in the cell supernatant. Functional enrichment analysis of impacted transcripts identified the anti-inflammatory IL10 signalling pathway. Western blot analysis of CARS2 silenced macrophages revealed reduced STAT3 phosphorylation in response to IL-10 and increased expression of LPS-induced genes that are repressed by IL-10, indicating a role for CARS2 in anti-inflammatory signalling. Finally, to simulate vessel wall conditions, macrophages, and smooth muscle cells (SMC) were maintained in co-culture. Significantly, CARS2 silencing in macrophages altered the SMC phenotype, decreasing expression of contractile genes and increasing expression of inflammatory genes. CONCLUSIONS: These data highlight a novel anti-inflammatory novel role for CARS2 in human macrophages and SMCs that may underlie the protective effect of a common GWAS-identified variant.


Assuntos
Doença da Artéria Coronariana , Interleucina-10 , Anti-Inflamatórios/farmacologia , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/metabolismo , Citocinas/metabolismo , Estudo de Associação Genômica Ampla , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Macrófagos/metabolismo
11.
iScience ; 24(1): 101900, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33364588

RESUMO

BTN3A molecules-BTN3A1 in particular-emerged as important mediators of Vγ9Vδ2 T cell activation by phosphoantigens. These metabolites can originate from infections, e.g. with Mycobacterium tuberculosis, or by alterations in cellular metabolism. Despite the growing interest in the BTN3A genes and their high expression in immune cells and various cancers, little is known about their transcriptional regulation. Here we show that these genes are induced by NLRC5, a regulator of MHC class I gene transcription, through an atypical regulatory motif found in their promoters. Accordingly, a robust correlation between NLRC5 and BTN3A gene expression was found in healthy, in M. tuberculosis-infected donors' blood cells, and in primary tumors. Moreover, forcing NLRC5 expression promoted Vγ9Vδ2 T-cell-mediated killing of tumor cells in a BTN3A-dependent manner. Altogether, these findings indicate that NLRC5 regulates the expression of BTN3A genes and hence open opportunities to modulate antimicrobial and anticancer immunity.

12.
Sci Rep ; 11(1): 16436, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385540

RESUMO

Targeted therapy with tyrosine kinase inhibitors (TKI) provides survival benefits to a majority of patients with non-small cell lung cancer (NSCLC). However, resistance to TKI almost always develops after treatment. Although genetic and epigenetic alterations have each been shown to drive resistance to TKI in cell line models, clinical evidence for their contribution in the acquisition of resistance remains limited. Here, we employed liquid biopsy for simultaneous analysis of genetic and epigenetic changes in 122 Vietnamese NSCLC patients undergoing TKI therapy and displaying acquired resistance. We detected multiple profiles of resistance mutations in 51 patients (41.8%). Of those, genetic alterations in EGFR, particularly EGFR amplification (n = 6), showed pronounced genome instability and genome-wide hypomethylation. Interestingly, the level of hypomethylation was associated with the duration of response to TKI treatment. We also detected hypermethylation in regulatory regions of Homeobox genes which are known to be involved in tumor differentiation. In contrast, such changes were not observed in cases with MET (n = 4) and HER2 (n = 4) amplification. Thus, our study showed that liquid biopsy could provide important insights into the heterogeneity of TKI resistance mechanisms in NSCLC patients, providing essential information for prediction of resistance and selection of subsequent treatment.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/patologia , Variações do Número de Cópias de DNA , Metilação de DNA , Resistencia a Medicamentos Antineoplásicos/genética , Biópsia Líquida/métodos , Neoplasias Pulmonares/patologia , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Estudos de Coortes , Receptores ErbB/genética , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade
13.
Sci Rep ; 10(1): 2707, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066856

RESUMO

Comprehensive profiling of actionable mutations in non-small cell lung cancer (NSCLC) is vital to guide targeted therapy, thereby improving the survival rate of patients. Despite the high incidence and mortality rate of NSCLC in Vietnam, the actionable mutation profiles of Vietnamese patients have not been thoroughly examined. Here, we employed massively parallel sequencing to identify alterations in major driver genes (EGFR, KRAS, NRAS, BRAF, ALK and ROS1) in 350 Vietnamese NSCLC patients. We showed that the Vietnamese NSCLC patients exhibited mutations most frequently in EGFR (35.4%) and KRAS (22.6%), followed by ALK (6.6%), ROS1 (3.1%), BRAF (2.3%) and NRAS (0.6%). Interestingly, the cohort of Vietnamese patients with advanced adenocarcinoma had higher prevalence of EGFR mutations than the Caucasian MSK-IMPACT cohort. Compared to the East Asian cohort, it had lower EGFR but higher KRAS mutation prevalence. We found that KRAS mutations were more commonly detected in male patients while EGFR mutations was more frequently found in female. Moreover, younger patients (<61 years) had higher genetic rearrangements in ALK or ROS1. In conclusions, our study revealed mutation profiles of 6 driver genes in the largest cohort of NSCLC patients in Vietnam to date, highlighting significant differences in mutation prevalence to other cohorts.


Assuntos
Adenocarcinoma/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/etnologia , Adenocarcinoma/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Quinase do Linfoma Anaplásico/genética , Povo Asiático , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/etnologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Análise Mutacional de DNA , Receptores ErbB/genética , Feminino , GTP Fosfo-Hidrolases/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Incidência , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/etnologia , Neoplasias Pulmonares/mortalidade , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Fatores Sexuais , Análise de Sobrevida , Vietnã/epidemiologia
14.
Front Oncol ; 10: 1351, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32850431

RESUMO

Population-specific profiling of mutations in cancer genes is of critical importance for the understanding of cancer biology in general as well as the establishment of optimal diagnostics and treatment guidelines for that particular population. Although genetic analysis of tumor tissue is often used to detect mutations in cancer genes, the invasiveness and limited accessibility hinders its application in large-scale population studies. Here, we used ultra-deep massive parallel sequencing of plasma cell free DNA (cfDNA) to identify the mutation profiles of 265 Vietnamese patients with advanced non-small cell lung cancer (NSCLC). Compared to a cohort of advanced NSCLC patients characterized by sequencing of tissue samples, cfDNA genomic testing, despite lower mutation detection rates, was able to detect major mutations in tested driver genes that reflected similar mutation composition and distribution pattern, as well as major associations between mutation prevalence and clinical features. In conclusion, ultra-deep sequencing of plasma cfDNA represents an alternative approach for population-wide genetic profiling of cancer genes where recruitment of patients is limited to the accessibility of tumor tissue site.

15.
Antimicrob Agents Chemother ; 53(11): 4835-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19721073

RESUMO

Consecutive fluoroquinolone (FQ)-resistant isolates (n = 109) identified at the Pham Ngoc Thach Hospital for Tuberculosis, Ho Chi Minh City, Vietnam, were sequenced in the quinolone resistance-determining regions of the gyrA and gyrB genes and typed by large sequence polymorphism typing and spoligotyping to identify the Beijing genotype of Mycobacterium tuberculosis. Beijing genotype prevalence was compared with 109 consecutive isolates from newly presenting patients with pulmonary tuberculosis from the hospital outpatient department. Overall, 82.6% (n = 90/109) of isolates had mutations in gyrAB. Nine novel mutations were identified in gyrB (S486F, N538T, T539P, D500A, D500H, D500N, G509A, E540V, and E540D). The influence of these novel gyrB mutations on FQ resistance is not proven. The Beijing genotype was significantly associated with FQ resistance (odds ratio [OR], 2.39 [95% confidence interval {CI}, 1.34 to 4.25]; P = 0.003). Furthermore, Beijing genotype FQ-resistant isolates were significantly more likely than FQ-resistant isolates of other genotypes to have gyrA mutations (OR, 7.75 [95% CI, 2.84 to 21.15]; P = 0.0001) and high-level (>8 microg/ml) FQ resistance (OR, 11.0 [95% CI, 2.6 to 47.0]; P = 0.001). The underlying mechanism of the association of the Beijing genotype with high-level FQ resistance in this setting remains to be determined. The association of the Beijing genotype with relatively high-level FQ resistance conferred by specific gyrA mutations reported here is of grave concern given the epidemic spread of the Beijing genotype and the current hopes for shorter first-line treatment regimens based on FQs.


Assuntos
Anti-Infecciosos/farmacologia , Fluoroquinolonas/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Técnicas de Tipagem Bacteriana , DNA Girase/genética , Farmacorresistência Bacteriana , Genótipo , Testes de Sensibilidade Microbiana , Mutação , Mycobacterium tuberculosis/classificação
16.
Mucosal Immunol ; 12(4): 843-850, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30976087

RESUMO

The microbiota plays an essential role in the education, development, and function of the immune system, both locally and systemically. Emerging experimental and epidemiological evidence highlights a crucial cross-talk between the intestinal microbiota and the lungs, termed the 'gut-lung axis'. Changes in the constituents of the gut microbiome, through either diet, disease or medical interventions (such as antibiotics) is linked with altered immune responses and homeostasis in the airways. The importance of the gut-lung axis has become more evident following the identification of several gut microbe-derived components and metabolites, such as short-chain fatty acids (SCFAs), as key mediators for setting the tone of the immune system. Recent studies have supported a role for SCFAs in influencing hematopoietic precursors in the bone marrow-a major site of innate and adaptive immune cell development. Here, we review the current understanding of host-microbe cross-talk along the gut-lung axis. We highlight the importance of SCFAs in shaping and promoting bone marrow hematopoiesis to resolve airway inflammation and to support a healthy homeostasis.


Assuntos
Metabolismo Energético , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Homeostase , Pulmão/fisiologia , Microbiota , Animais , Medula Óssea , Disbiose , Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal/imunologia , Trato Gastrointestinal/imunologia , Hematopoese , Humanos , Imunomodulação , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia
17.
J Pathol Transl Med ; 53(6): 361-368, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31525834

RESUMO

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal neoplasms of the gastrointestinal tract. Management of GIST patients is currently based on clinicopathological features and associated genetic changes. However, the detailed characteristics and molecular genetic features of GISTs have not yet been described in the Vietnamese population. METHODS: We first identified 155 patients with primary GIST who underwent surgery with primary curative intent between 2011 and 2014 at University Medical Center at Ho Chi Minh City, Vietnam. We evaluated the clinicopathological features and immunohistochemical reactivity to p53 and Ki-67 in these patients. Additionally, KIT genotyping was performed in 100 cases. RESULTS: The largest proportion of GISTs was classified as high-risk (43.2%). Of the 155 GISTs, 52 (33.5%) were positive for Ki-67, and 58 (37.4%) were positive for p53. The expression of Ki-67 and p53 were correlated with mitotic rate, tumor size, risk assessment, and tumor stage. Out of 100 GIST cases, KIT mutation was found in 68%, of which 62 (91.2%) were found in exon 11, two (2.9%) in exon 9, and four (5.8%) in exon 17. No mutation in exon 13 was identified. Additionally, KIT mutations did not correlate with any clinicopathological features. CONCLUSIONS: The expression of Ki-67 and p53 were associated with high-risk tumors. Mutations in exon 11 were the most commonly found, followed by exon 17 and exon 9. Additionally, KIT mutation status was not correlated with any recognized clinicopathological features.

18.
PLoS One ; 14(12): e0226193, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31841547

RESUMO

The identification and quantification of actionable mutations are of critical importance for effective genotype-directed therapies, prognosis and drug response monitoring in patients with non-small-cell lung cancer (NSCLC). Although tumor tissue biopsy remains the gold standard for diagnosis of NSCLC, the analysis of circulating tumor DNA (ctDNA) in plasma, known as liquid biopsy, has recently emerged as an alternative and noninvasive approach for exploring tumor genetic constitution. In this study, we developed a protocol for liquid biopsy using ultra-deep massively parallel sequencing (MPS) with unique molecular identifier tagging and evaluated its performance for the identification and quantification of tumor-derived mutations from plasma of patients with advanced NSCLC. Paired plasma and tumor tissue samples were used to evaluate mutation profiles detected by ultra-deep MPS, which showed 87.5% concordance. Cross-platform comparison with droplet digital PCR demonstrated comparable detection performance (91.4% concordance, Cohen's kappa coefficient of 0.85 with 95% CI = 0.72-0.97) and great reliability in quantification of mutation allele frequency (Intraclass correlation coefficient of 0.96 with 95% CI = 0.90-0.98). Our results highlight the potential application of liquid biopsy using ultra-deep MPS as a routine assay in clinical practice for both detection and quantification of actionable mutation landscape in NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , DNA Tumoral Circulante/análise , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias Pulmonares/genética , Reação em Cadeia da Polimerase/métodos , Sitios de Sequências Rotuladas , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/patologia , DNA Tumoral Circulante/genética , Código de Barras de DNA Taxonômico/métodos , Análise Mutacional de DNA/métodos , DNA de Neoplasias/análise , DNA de Neoplasias/genética , DNA de Neoplasias/isolamento & purificação , Receptores ErbB/genética , Feminino , GTP Fosfo-Hidrolases/genética , Humanos , Limite de Detecção , Biópsia Líquida , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patologia , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Reprodutibilidade dos Testes
19.
Org Lett ; 10(2): 233-6, 2008 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-18092790

RESUMO

Several 4-methoxyxanthones and 3,4-dimethoxyxanthones were synthesized in good yield via inverse-electron-demand Diels-Alder (IEDDA) driven domino reactions between a series of electron-deficient chromone-fused dienes with 1-(2,2-dimethoxyvinyl)pyrrolidine or tetramethoxyethene, respectively.


Assuntos
Polienos/síntese química , Xantonas/síntese química , Estrutura Molecular , Polienos/química , Xantonas/química
20.
Cell Rep ; 23(1): 39-49, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29617671

RESUMO

In chronic infection and cancer, T cells acquire a dysfunctional state characterized by the expression of inhibitory receptors. In vitro studies implicated the phosphatase Shp-2 downstream of these receptors, including PD-1. However, whether Shp-2 is responsible in vivo for such dysfunctional responses remains elusive. To address this, we generated T cell-specific Shp-2-deficient mice. These mice did not show differences in controlling chronic viral infections. In this context, Shp-2-deleted CD8+ T lymphocytes expanded moderately better but were less polyfunctional than control cells. Mice with Shp-2-deficient T cells also showed no significant improvement in controlling immunogenic tumors and responded similarly to controls to α-PD-1 treatment. We therefore showed that Shp-2 is dispensable in T cells for globally establishing exhaustion and for PD-1 signaling in vivo. These results reveal the existence of redundant mechanisms downstream of inhibitory receptors and represent the foundation for defining these relevant molecular events.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias Experimentais/imunologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Transdução de Sinais , Viroses/imunologia , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1/imunologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/imunologia
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