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1.
Dermatology ; 237(2): 283-290, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32799209

RESUMO

BACKGROUND: The thioredoxin-interacting protein (TXNIP) is involved in cellular metabolism and cell proliferation, and recently, deficient expression of TXNIP has been associated with progression and poor outcome for cancer patients. OBJECTIVES: To assess TXNIP expression and function in malignant T cells from cutaneous T-cell lymphoma (CTCL). METHODS: CTCL-derived malignant (MyLa2059, PB2B) and non-malignant (MyLa1850) cell lines were analysed by Western blotting and qPCR for TXNIP expression. Subsequently, the malignant CTCL cell lines were treated with GSK126 - an inhibitor of enhancer of zeste homolog 2 (EZH2) methyltransferase activity or assessed by bisulphite sequencing for TXNIP promoter methylation. Methylation was also assessed with the demethylating agent 5-azacytidine (5AZA). Finally, TXNIP was overexpressed in the malignant PB2B cell line via plasmid transduction, and the effect of TXNIP was further analysed by flow cytometry. RESULTS: We report on low expression of TXNIP protein in all cell lines representing different subtypes and stages of CTCL when compared to non-malignant T cells. Epigenetic silencing and other mechanisms were involved in the repression of TXNIP whereas forced expression of TXNIP strongly inhibited proliferation of malignant T cells. CONCLUSIONS: Epigenetic silencing and other as yet unknown mechanisms repress TXNIP expression in malignant T cells. As forced expression of TXNIP inhibits malignant proliferation, we propose that TXNIP is a putative tumour suppressor in CTCL.


Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linfoma Cutâneo de Células T/patologia , Neoplasias Cutâneas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Epigênese Genética , Inativação Gênica , Humanos , Indóis/farmacologia , Regiões Promotoras Genéticas , Piridonas/farmacologia
2.
Subcell Biochem ; 61: 455-78, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23150263

RESUMO

In higher eukaryotic organisms epigenetic modifications are crucial for proper chromatin folding and thereby proper regulation of gene expression. In the last years the involvement of aberrant epigenetic modifications in inflammatory and autoimmune diseases has been recognized and attracted significant interest. However, the epigenetic mechanisms underlying the different disease phenotypes are still poorly understood. As autoimmune and inflammatory diseases are at least partly T cell mediated, we will provide in this chapter an introduction to the epigenetics of T cell differentiation followed by a summary of the current knowledge on aberrant epigenetic modifications that dysfunctional T cells display in various diseases such as type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, and asthma.


Assuntos
Doenças Autoimunes/genética , Autoimunidade/genética , Epigênese Genética , Inflamação/genética , Subpopulações de Linfócitos T/imunologia , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Diferenciação Celular/genética , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Citocinas/genética , Citocinas/metabolismo , Regulação da Expressão Gênica , Predisposição Genética para Doença , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Fenótipo , Transdução de Sinais , Subpopulações de Linfócitos T/metabolismo
3.
J Eat Disord ; 12(1): 35, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429839

RESUMO

BACKGROUND: Eating Disorders (ED) are severe and costly mental health disorders. The effects of existing treatment approaches are limited and there is a need to develop novel interventions, including digital strategies that can increase engagement and effectiveness. Maze Out is a new serious game coproduced by patients and ED therapists, which allows patients to "play" with the reality of an ED and reflect on associated challenges. OBJECTIVES: The present study has two main objectives: (1) to evaluate the effectiveness of adding Maze Out to treatment as usual (TAU) in a randomised controlled trial (RCT); and (2) to examine in depth the potential of Maze Out by examining how it is perceived and used in the context of an RCT. METHODS: Participants will be recruited from mental health care services, endocrinology departments or Community Centres offering treatment for ED. Patients suffering from ED (N = 94) will be randomised to either TAU or TAU plus Maze Out. Primary outcome will be measured in terms of changes in self-efficacy, measured by a 5-item self-efficacy questionnaire (5-item SE_ED). Secondary outcome measures will include feelings of ineffectiveness and self-image, as measured by Eating Disorder Inventory, version 3 (EDI-3), Brief INSPIRE-O and Structural Analysis of Social Behaviour Intrex Questionnaire (SAS-B). Data will be collected at baseline (enrolment in the study), and subsequently 8 and 15 weeks after inclusion. Experiences of playing Maze Out will be examined in a sub-sample of participants, utilising both quantitative user analytics and qualitative interview data of patients, interview data of significant others, and healthcare professionals to explore the possible impact of Maze Out on disorder insight, communication patterns between patients and therapists and understanding of their disorder. DISCUSSION: To our knowledge Maze Out is the first serious game coproduced by patients and therapists. It is a novel and theoretically grounded intervention that may significantly contribute to the healing process of ED. If found effective, the potential for wide-spread impact and scalability is considerable. Trial registration ClinicalTrials.gov NCT05621018.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38426346

RESUMO

CONTEXT: The risk of gestational diabetes mellitus (GDM) differs between the Danish population and several migrant groups. However, it is unclear if the incidence and timing of type 2 diabetes mellitus (T2DM) following GDM vary similarly. OBJECTIVE: To investigate the incidence of T2DM according to migration background based on country/region of origin among women with a previous GDM diagnosis and explore the role of time since GDM diagnosis on the association. METHOD: Using nationwide registry data, we followed women diagnosed with GDM in Denmark during 2004-2018 to Dec 31, 2020. Poisson regression models were used to estimate incidence rates (IRs) of T2DM according to country/region of origin, adjusted for age, education, and body mass index. RESULTS: The study included 20,873 women with a GDM diagnosis, of whom 22.3% were of migrant background and 77.7% were Danish. The mean follow-up time was 7.3 years, and 10.9% were registered with T2DM during the study period. Generally, migrant women had higher IRs of T2DM compared to Danish women, with substantial variations in risk between migrant groups. Women from Pakistan and Sri Lanka had three-four times higher IRs compared to Danish women. The timing of T2DM onset also varied, with women from Sri Lanka and Pakistan having an earlier onset of T2DM compared to other migrant and Danish women. CONCLUSION: This study demonstrated that country/region of origin is an important risk factor for T2DM in women with GDM. These findings underscore the importance of prevention programs targeting women with GDM and a high-risk origin.

5.
J Imaging Inform Med ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38548991

RESUMO

The aim of this study was to assess and evaluate the individual expectations and experiences regarding the implementation of digital pathology (DIPA) among clinical staff in two of the pathology departments in the Region of Southern Denmark before and during the implementation in their department. Seventeen semi-structured interviews based upon McKinsey 7-S framework were held both prior to and during implementation with both managers and employees at the two pathology departments. The interviewees were pathologists, medical doctors in internship in pathology (interns), biomedical laboratory scientists (BLS), secretaries, and a project lead. Using deductive and inductive coding resulted in five overall themes and appertaining sub-themes. The findings pointed to an overall positive attitude towards DIPA from the beginning. The clinical staff perceived being rewarded already during implementation with benefits such as improved collaboration both inter- and intra-departmentally promoting better acceptance of DIPA. The clinical staff also experienced some challenges, e.g., increase in turnaround times, which affected and concerned staff on a personal level. Especially BLS expressed experiencing a demanding and stressful transition due to unexpected increase in workload as well as some barriers for a potentially better implementation process. The key findings of this study were a need for better preparation of staff through transparent communication of the upcoming challenges of the transition to DIPA, more system-specific training beforehand, more allocation of time and resources in the implementation process, and more focus on BLS' work tasks in the requirement specifications.

6.
Hum Mutat ; 34(11): 1568-80, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24038839

RESUMO

A number of methods allowing the detection of low levels of KRAS mutations have been developed in the last years. However, although these methods have become increasingly sensitive, they can rarely identify the mutated base directly without prior knowledge on the mutated base and are often incompatible with a sequencing-based read-out desirable in clinical practice. Here, we present a modified version of the ice-COLD-PCR assay called Enhanced-ice-COLD-PCR (E-ice-COLD-PCR) for KRAS mutation detection and identification, which allows the enrichment of the six most frequent KRAS mutations. The method is based on a nonextendable chemically modified blocker sequence, complementary to the wild-type (WT) sequence leading to the enrichment of mutated sequences. This assay permits the reliable detection of down to 0.1% mutated sequences in a WT background. A single genotyping assay of the amplification product by pyrosequencing directly following the E-ice-COLD-PCR is performed to identify the mutated base. This developed two-step method is rapid and cost-effective, and requires only a small amount of starting material permitting the sensitive detection and sequence identification of KRAS mutations within 3 hr. This method is applied in the current study to clinical colorectal cancer samples and enables detection of mutations in samples, which appear as WT using standard detection technologies.


Assuntos
Análise Mutacional de DNA/métodos , Mutação , Reação em Cadeia da Polimerase/métodos , Proteínas ras/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Humanos , Sensibilidade e Especificidade
7.
J Clin Endocrinol Metab ; 108(12): e1551-e1559, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37379575

RESUMO

CONTEXT: Children exposed to gestational diabetes mellitus (GDM) in utero are at high risk of developing overweight and obesity, but their postnatal growth trajectories and risk profiles remain unclear. OBJECTIVE: We aimed to identify distinct body mass index (BMI) trajectories from birth to 10 years of age in children exposed to GDM and to explore their associations with infant and maternal characteristics. METHODS: This nationwide cohort study linked data from Danish registries on 15 509 children exposed to GDM in utero, born in Denmark from January 2008 to October 2019. We applied latent class trajectory modeling to identify distinct BMI trajectories. Associations of BMI trajectories with infant and maternal characteristics were analyzed using multiple linear regression. RESULTS: We identified 3 distinct BMI trajectories characterized by a "normal" (60%), a "late accelerating" (28%) and an "early accelerating" (12%) BMI trajectory, the 2 latter at risk of overweight and obesity, respectively, at age 10 years, relative to World Health Organization child growth standards. Children in the "late accelerating" BMI trajectory were more often born large for gestational age (P < .001). More children in the "early accelerating" BMI trajectory were boys, born small for gestational age, and had mothers with a higher pre-pregnancy BMI compared to the other groups (P < .001). CONCLUSION: Children exposed to GDM in utero differ widely in their BMI trajectory. The detection of risk profiles based on early BMI growth and infant and maternal characteristics provides an opportunity for future targeted care and prevention.


Assuntos
Diabetes Gestacional , Gravidez , Lactente , Masculino , Feminino , Criança , Humanos , Diabetes Gestacional/epidemiologia , Índice de Massa Corporal , Sobrepeso/epidemiologia , Sobrepeso/complicações , Estudos de Coortes , Peso ao Nascer , Fatores de Risco , Obesidade/complicações , Mães
8.
Animals (Basel) ; 12(7)2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35405908

RESUMO

The present study aimed (1) to estimate the size of the population of unowned free-ranging domestic cats in Denmark using a questionnaire survey combined with a GPS-tracking survey, and (2) to estimate the distribution of the population across different habitats. The questionnaires were circulated in 94 randomly selected parishes ranging across seven kinds of habitat. Using responses from five of the habitats, we estimated the population of unowned free-ranging cats nationally. In the other two habitats, questionnaire data were collected in a simpler way. The territory of 59 owned cats was estimated with GPS tracking to assess home ranges. Home range area was calculated using 95% Brownian bridge kernel density estimation (0.033-0.077 ± 0.011-0.023 km2, median ± SE). We estimated a population of unowned free-ranging cats in Denmark of 89,000 ± 11,000 (SE), with a mean density of 2 ± 0.3 (SE) cats per km2, living primarily in rural habitats. Approximately one-third of the cats were estimated to be socialised and two-thirds unsocialised. Our method may be suitable for use in other temperate areas facing problems with unowned free-ranging cats.

9.
Insects ; 12(3)2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33801241

RESUMO

Thrips are a major pest in protected strawberry production. Knowledge of thrips species composition could be instrumental for improved thrips management, but very little is known about which species are present in strawberries grown in high-tunnels in Denmark. Thrips (adults and larvae) were sampled in two strawberry tunnels of the cultivars Murano and Furore from May to August 2018, in the middle and in the edges of the tunnels. The most abundant thrips species found in the tunnels were Frankliniella intonsa and Thrips tabaci adults. Frankliniella intonsa were also the most frequently found species of the immatures sampled, followed by T. tabaci larvae, and other species. The number of thrips differed between the two cultivars, sampling times and location in the tunnel. Frankliniella intonsa was more abundant in the middle of the tunnels, while T. tabaci was more abundant in the edge of the tunnels adjacent to the field margins. The number of thrips peaked by the end of July. Both chemical and biological control should consider species composition and occurrence; hence, a fundamental first step for thrips management is to identify the species present on the target crop.

11.
Sci Rep ; 7(1): 6774, 2017 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-28754985

RESUMO

This is the first study to compare genome-wide DNA methylation profiles of sorted blood cells from myelofibrosis (MF) patients and healthy controls. We found that differentially methylated CpG sites located to genes involved in 'cancer' and 'embryonic development' in MF CD34+ cells, in 'inflammatory disease' in MF mononuclear cells, and in 'immunological diseases' in MF granulocytes. Only few differentially methylated CpG sites were common among the three cell populations. Mutations in the epigenetic regulators ASXL1 (47%) and TET2 (20%) were not associated with a specific DNA methylation pattern using an unsupervised approach. However, in a supervised analysis of ASXL1 mutated versus wild-type cases, differentially methylated CpG sites were enriched in regions marked by histone H3K4me1, histone H3K27me3, and the bivalent histone mark H3K27me3 + H3K4me3 in human CD34+ cells. Hypermethylation of selected CpG sites was confirmed in a separate validation cohort of 30 MF patients by pyrosequencing. Altogether, we show that individual MF cell populations have distinct differentially methylated genes relative to their normal counterparts, which likely contribute to the phenotypic characteristics of MF. Furthermore, differentially methylated CpG sites in ASXL1 mutated MF cases are found in regulatory regions that could be associated with aberrant gene expression of ASXL1 target genes.


Assuntos
Metilação de DNA/genética , Epigênese Genética , Mutação/genética , Mielofibrose Primária/genética , Proteínas Repressoras/genética , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/metabolismo , Análise por Conglomerados , Ilhas de CpG/genética , Proteínas de Ligação a DNA/genética , Dioxigenases , Feminino , Granulócitos/metabolismo , Histonas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Oncogenes , Proteínas Proto-Oncogênicas/genética , Reprodutibilidade dos Testes
12.
Oncotarget ; 6(38): 40588-97, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26497854

RESUMO

A thorough understanding of the idiopathic hypereosinophilic syndrome (IHES) and further optimization of diagnostic work-up procedures are warranted. We analyzed purified eosinophils from patients with IHES by next-generation whole-exome sequencing and compared DNA methylation profiles from reactive eosinophilic conditions to known clonal and suspected clonal eosinophilia. Somatic missense mutations in cancer-related genes were detected in three IHES patients. These included the spliceosome gene PUF60 and the cadherin gene CDH17. Furthermore, reactive eosinophilia samples could be differentiated from known- and suspected clonal eosinophilia samples based on 285 differentially methylated CpG sites corresponding to 128 differentially methylated genes. Using Ingenuity pathway analysis, we found that differentially methylated genes were highly enriched in functional pathways such as cancer, cell death and survival, and hematological disease. Our data show that a subset of IHES may be of clonal origin not related to the classical molecular aberrations of FGFR, PDGFRA/B, or T-cells, and that the initiating hits could be point mutations in a variety of genes, including spliceosome mutations or hypermethylated tumor suppressor genes. In addition, we identified a DNA methylation signature that is relevant for distinguishing clonal and suspected clonal eosinophilia from reactive eosinophilia per se, which may be useful in daily clinical work.


Assuntos
Biomarcadores/metabolismo , Metilação de DNA , Exoma/genética , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Síndrome Hipereosinofílica/genética , Mutação/genética , Diferenciação Celular , Feminino , Estudo de Associação Genômica Ampla , Humanos , Síndrome Hipereosinofílica/patologia , Masculino , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Endocr Relat Cancer ; 22(6): 953-67, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26400872

RESUMO

Overexpression of insulin growth factor 2 (IGF2) is a hallmark of adrenocortical carcinomas and pheochromocytomas. Previous studies investigating the IGF2/H19 locus have mainly focused on a single molecular level such as genomic alterations or altered DNA methylation levels and the causal changes underlying IGF2 overexpression are still not fully established. In the current study, we analyzed 62 tumors of the adrenal gland from patients with Conn's adenoma (CA, n=12), pheochromocytomas (PCC, n=10), adrenocortical benign tumors (ACBT, n=20), and adrenocortical carcinomas (ACC, n=20). Gene expression, somatic copy number variation of chr11p15.5, and DNA methylation status of three differential methylated regions of the IGF2/H19 locus including the H19 imprinting control region were integratively analyzed. IGF2 overexpression was found in 85% of the ACCs and 100% of the PCCs compared to 23% observed in CAs and ACBTs. Copy number aberrations of chr11p15.5 were abundant in both PCCs and ACCs but while PCCs retained a diploid state, ACCs were frequently tetraploid (7/19). Loss of either a single allele or loss of two alleles of the same parental origin in tetraploid samples resulted in a uniparental disomy-like genotype. These copy number changes correlated with hypermethylation of the H19 ICR suggesting that the lost alleles were the unmethylated maternal alleles. Our data provide conclusive evidence that loss of the maternal allele correlates with IGF2 overexpression in adrenal tumors and that hypermethylation of the H19 ICR is a consequence thereof.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Adenoma Adrenocortical/genética , Carcinoma/genética , Metilação de DNA , Dosagem de Genes , Regulação Neoplásica da Expressão Gênica/genética , Fator de Crescimento Insulin-Like II/genética , Proteínas de Neoplasias/genética , Feocromocitoma/genética , Neoplasias das Glândulas Suprarrenais/metabolismo , Adenoma Adrenocortical/metabolismo , Adulto , Idoso , Alelos , Carcinoma/metabolismo , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 11/ultraestrutura , Feminino , Impressão Genômica , Genótipo , Humanos , Fator de Crescimento Insulin-Like II/biossíntese , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Feocromocitoma/metabolismo , Ploidias , Polimorfismo de Nucleotídeo Único , Regulação para Cima
14.
Clin Respir J ; 8(3): 274-80, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23911061

RESUMO

BACKGROUND AND AIMS: Chronic obstructive pulmonary disease (COPD) is a common disease, especially among smokers. The disease is underdiagnosed, and patients often suffer from comorbidities. The aims of this study were to elucidate the prevalence of COPD as comorbidity in a university hospital setting, to characterise patients demographically, to investigate comorbidities in patients suffering from COPD and lastly, to analyse whether CODP as comorbidity influenced the length of stay. METHODS: Aalborg University Hospital covers all medical and surgical specialities. A 1-day cross-sectional study was carried out in the entire hospital. A spirometry was performed on the patients. Data on smoking habits, prior lung function measurements, prescribed lung medicine and self-evaluated dyspnoea, using the Medical Research Council score and body mass index were recorded. The final diagnosis was registered after 1 month. RESULTS: Two hundred fifteen patients participated, and 28% suffered from COPD. Sixteen per cent had mild, 48% moderate, 18% severe and 18% very severe COPD. Seventy-seven per cent were newly diagnosed at our examination. COPD patients did not have significantly more comorbidities than non-COPD patients. Gastrointestinal diseases, haematologic diseases and uro-nephrologic diseases were significantly more prevalent in COPD patients. Duration of stay was significantly longer among COPD patients compared with non-COPD patients, P < 0.05. CONCLUSION: Seventy-seven per cent of the COPD patients in this study were newly diagnosed at our examination. Gastrointestinal diseases, haematologic diseases and uro-nephrologic diseases were significantly more prevalent in COPD patients. COPD patients were hospitalised significantly longer than non-COPD patients.


Assuntos
Hospitalização , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Idoso , Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , Comorbidade , Estudos Transversais , Dinamarca/epidemiologia , Feminino , Gastroenteropatias/epidemiologia , Doenças Hematológicas/epidemiologia , Hospitais Universitários , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Prevalência , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Índice de Gravidade de Doença , Doenças Urológicas/epidemiologia
15.
Oncotarget ; 5(7): 1912-25, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24722400

RESUMO

MiR34A, B and C have been implicated in lymphomagenesis, but information on their role in normal CD19+ B-cells (PBL-B) and de novo diffuse large B-cell lymphoma (DLBCL) is limited. We show that in normal and activated B-cells miR34A-5p plays a dominant role compared to other miR34 family members. Only miR34A-5p is expressed in PBL-B, and significantly induced in activated B-cells and reactive lymph nodes. In PBL-B, the MIR34A and MIR34B/C promoters are unmethylated, but the latter shows enrichment for the H3K4me3/H3K27me3 silencing mark. Nine de novo DLBCL cases (n=150) carry both TP53 mutation and MIR34A methylation ("double hit") and these patients have an exceedingly poor prognosis with a median survival of 9.4 months (P<0.0001), while neither TP53 mutation, MIR34A or MIR34B/C promoter methylation alone ("single hit") influence on survival. The TP53/MIR34A "double-hit" is an independent negative prognostic factor for survival (P=0.0002). In 2 DLBCL-cell lines with both TP53 mutation and promoter methylation of MIR34A, miR34A-5p is upregulated by 5-aza-2'deoxycytidine. Thus, the TP53/MIR34A "double hit" characterizes a very aggressive subgroup of DLBCL, which may be treatable with epigenetic therapy prior to or in combination with conventional immunochemotherapy.


Assuntos
Linfoma Difuso de Grandes Células B/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Regiões Promotoras Genéticas/genética , Proteína Supressora de Tumor p53/genética , Idoso , Antígenos CD19/análise , Linfócitos B/química , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Códon sem Sentido , Feminino , Humanos , Linfonodos/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Metilação , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Prognóstico , Taxa de Sobrevida
16.
Sci Rep ; 3: 2789, 2013 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-24071855

RESUMO

The tumor suppressor genes MGMT and DAPK1 become methylated in several cancers including diffuse large B-cell lymphoma (DLBCL). However, allelic methylation patterns have not been investigated in DLBCL. We developed a fast and cost-efficient method for the analysis of allelic methylation based on pyrosequencing of methylation specific PCR (MSP) products including a SNP. Allelic methylation patterns were reliably analyzed in standards of known allelic methylation status even when diluted in unmethylated DNA to below 1% methylation. When studying 148 DLBCL patients MGMT and DAPK1 methylation was observed in 19% and 89%, respectively, and among methylated and heterozygous patients 29% and 55%, respectively, were biallelically methylated. An association between the T-allele of the rs16906252 SNP and MGMT methylation was observed (p-value=0.04), and DAPK1 methylation of the A-allele was associated with shorter overall survival (p-value=0.006). In future cancer research allelic MSP-pyrosequencing may be used to study a wide range of other loci.


Assuntos
Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Proteínas Quinases Associadas com Morte Celular/genética , Linfoma Difuso de Grandes Células B/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Anticorpos Monoclonais Murinos , Protocolos de Quimioterapia Combinada Antineoplásica , Linhagem Celular , Ciclofosfamida , Doxorrubicina , Feminino , Genótipo , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Polimorfismo de Nucleotídeo Único , Prednisona , Rituximab , Sensibilidade e Especificidade , Análise de Sequência de DNA , Resultado do Tratamento , Vincristina , Adulto Jovem
17.
Biochimie ; 94(11): 2314-37, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22847185

RESUMO

A biomarker is a molecular target analyzed in a qualitative or quantitative manner to detect and diagnose the presence of a disease, to predict the outcome and the response to a specific treatment allowing personalized tailoring of patient management. Biomarkers can belong to different types of biochemical molecules such as proteins, DNA, RNA or lipids, whereby protein biomarkers have been the most extensively studied and used, notably in blood-based protein quantification tests or immunohistochemistry. The rise of interest in epigenetic mechanisms has allowed the identification of a new type of biomarker, DNA methylation, which is of great potential for many applications. This stable and heritable covalent modification mostly affects cytosines in the context of a CpG dinucleotide in humans. It can be detected and quantified by a number of technologies including genome-wide screening methods as well as locus- or gene-specific high-resolution analysis in different types of samples such as frozen tissues and FFPE samples, but also in body fluids such as urine, plasma, and serum obtained through non-invasive procedures. In some cases, DNA methylation based biomarkers have proven to be more specific and sensitive than commonly used protein biomarkers, which could clearly justify their use in clinics. However, very few of them are at the moment used in clinics and even less commercial tests are currently available. The objective of this review is to discuss the advantages of DNA methylation as a biomarker, the practical considerations for their development, and their use in disease detection, prediction of outcome or treatment response, through multiple examples mainly focusing on cancer, but also to evoke their potential for complex diseases and prenatal diagnostics.


Assuntos
Metilação de DNA , Marcadores Genéticos/genética , Animais , Epigênese Genética/genética , Humanos , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Neoplasias/genética
19.
Lung Cancer ; 71(2): 130-6, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20627446

RESUMO

Silencing of the DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) by promoter methylation is an early event in several human cancers. MGMT removes alkyl adducts from the O6 position of guanine thereby preventing G>A mutations in the genome. For this reason, MGMT promoter methylation predicts a favorable outcome for glioblastoma patients treated with alkylating agents. In this study, we investigated whether MGMT becomes silenced by promoter methylation in malignant pleural mesothelioma (MPM), an aggressive cancer of the pleura associated with a poor prognosis. Ninety-five samples from patients diagnosed with MPM were studied. These samples were genotyped for the MGMT rs16906252 promoter SNP using high-resolution melting, and methylation status was analyzed using SMART-MSP and confirmed by Sanger sequencing. The SMART-MSP assay was designed to provide information on the allelic methylation status in samples heterozygous for rs16906252. MGMT immunohistochemistry was performed on samples showing no methylation, monoallelic methylation, and biallelic methylation. Thirteen of the 95 MPM samples (13.7%) were methylation positive and a strong association with the T allele of the rs16906252 SNP (P<0.001) was observed. Detection of the protein was found to be dependent not only on the allelic methylation status but also on the methylation level, and complete silencing was observed in only one sample, showing biallelic methylation and a methylation level close to 100%. In conclusion, methylation of the MGMT promoter occurs in a subset of MPM patients and is associated with the T allele of the MGMT rs16906252 SNP. However, complete silencing of MGMT in MPM is a rare event.


Assuntos
Metilação de DNA , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Mesotelioma/genética , Neoplasias Pleurais/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Alelos , Predisposição Genética para Doença , Genótipo , Humanos , Mesotelioma/patologia , Neoplasias Pleurais/patologia
20.
Eur J Pharmacol ; 625(1-3): 131-42, 2009 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-19836388

RESUMO

In addition to the genetic alterations, observed in cancer cells, are mitotically heritable changes in gene expression not encoded by the DNA sequences, which are referred to as epigenetic changes. DNA methylation is among the most studied epigenetic mechanisms together with various histone modifications involved in chromatin remodeling. As opposed to genetic lesions, the epigenetic changes are potentially reversible by a number of small molecules, known as epi-drugs. This review will focus on the biological mechanisms underlying the epigenetic silencing of tumor suppressor genes observed in cancer cells, and the targeted molecular strategies that have been investigated to reverse these aberrations. In particular, we will focus on DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) as epigenetic targets for cancer treatment. A synergistic effect of a combined use of DNMT and HDAC inhibitors has been observed. Moreover, epi-drugs sensitize multiple different cancer cells to a large variety of other treatment strategies. In particular, we have focused on the ability of DNMT and HDAC inhibitors to restore the estrogen receptor alpha (ERalpha) activity in breast cancer. Finally, we will discuss the potential of DNA methylation changes as biomarkers to be used in diverse areas of cancer treatment, especially for predicting response to treatment with DNMT and HDAC inhibitors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Inativação Gênica , Neoplasias/tratamento farmacológico , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , Metilação de DNA/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Sinergismo Farmacológico , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Inibidores de Histona Desacetilases/farmacologia , Humanos , Neoplasias/genética
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