Download Consulta: subjectFacets:"Methylation" Registros recuperados: 14

Consulta: subjectFacets:"Methylation"
Registros recuperados: 14
Data/hora: 09/06/2017 03:11:56
A Michaelis–Menten type equation for describing methylmercury dependence on inorganic mercury
in aquatic sediments
Provedor de dados: 5
Autores: Cossa, Daniel; Garnier, Cedric; Buscail, Roselyne; Elbaz-poulichet, Francoise; Mikac, Nevenka; Patel-sorrentino,
Nathalie; Tessier, Erwan; Rigaud, Sylvain; Lenoble, Veronique; Gobeil, Charles.
Methylation of mercury (Hg) is the crucial process that controls Hg biomagnification along the aquatic food chains. Aquatic
sediments are of particular interest because they constitute an essential reservoir where inorganic divalent Hg (HgII) is
methylated. Methylmercury (MeHg) concentrations in sediments mainly result from the balance between methylation and
demethylation reactions, two opposite natural processes primarily mediated by aquatic microorganisms. Thus, Hg availability and
the activity of methylating microbial communities control the MeHg abundance in sediments. Consistently, some studies have
reported a significant positive correlation between MeHg and HgII or total Hg (HgT), taken as a proxy for HgII, in aquatic
sediments using...
Tipo: Text
Palavras-chave: Mercury; Methylmercury; Aquatic sediment; Methylation; Demethylation.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00171/28220/26520.pdf
Assessment of changes in the brca2 and p53 genes in breast invasive ductal carcinoma in northeast
Brazil
Provedor de dados: 48
Autores: Ramalho,Eduardo AVF; Silva-Filho,João LQ; Cartaxo,Marina FS; Cavalcanti,Carmelita BL; Rêgo,Moacyr JBM;
Oliveira,Maria BM; Beltrão,Eduardo IC.
BACKGROUND: BRCA protein interacts with at least 13 different proteins that have been implicated with cancer susceptibility
and loss of BRCA function is correlated to sensitivity to DNA crosslinking agents in preclinical models. RESULTS: BRCA2
methylation frequency was 44%, p53 Pro22 allele frequency was 32% and heterozygous frequency of Arg/Pro72 genotype was
60% which could be associated as risk factor for metastasis (p = 0.046 OR = 4.190). Regarding to polymorphism of codon 249 the
frequency of Arg249 allele presented 82% which was considered not statistically significant. CONCLUSIONS: There was not
statistical significance to BRCA2 promoter methylation with any parameters chosen. However, our findings suggest that patients
who present heterozygous...
Tipo: Journal article
Palavras-chave: Breast cancer; Epigenetics; Metastasis; Methylation; Polymorphism.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602014000100003
Characteristics of fads2 gene expression and putative promoter in European sea bass (Dicentrarchus
labrax): Comparison with salmonid species and analysis of CpG methylation
Provedor de dados: 5
Autores: Geay, Florian; Zambonino, Jose-luis; Reinhardt, Richard; Kuhl, Heiner; Santigosa, Ester; Cahu, Chantal; Mazurais,
David.
Marine fish species exhibit low capacity to biosynthesise highly unsaturated fatty acid (HUFA) in comparison to strict freshwater
and anadromous species. It is admitted that the Delta(6) desaturase (FADS2) is a key enzyme in the HUFA biosynthetic pathway.
We investigated by quantitative PCR the relative amounts of FADS2 mRNA in European sea bass (Dicentrarchus labrax) in
comparison with a salmonid species, the rainbow trout (Oncorhynchus mykiss L.). The analysis of the expression data was
performed regarding the difference of the characteristics of a critical fragment of the fads2 gene promoter between sea bass and
Atlantic salmon. The lower level of fads2 gene expression observed in sea bass suggested that fads2 gene putative promoter,
which exhibited an...
Tipo: Text
Palavras-chave: FADS2; Sea bass; Gene expression; Promoter; Methylation.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00065/17621/15310.pdf
Clinicopathological significance of PTPN12 expression in human breast cancer
Provedor de dados: 56
Autores: Xunyi,Yuan; Zhentao,Yuan; Dandan,Jiang; Funian,Li.
Protein tyrosine phosphatase non-receptor type 12 (PTPN12) is a recently identified tumor suppressor gene (TSG) that is
frequently compromised in human triple-negative breast cancer. In the present study, we investigated the expression of PTPN12
protein by patients with breast cancer in a Chinese population and the relationship between PTPN12 expression levels and patient
clinicopathological features and prognosis. Additionally, we explored the underlying down-regulation mechanism from the
perspective of an epigenetic alteration. We examined PTPN12 mRNA expression in five breast cancer cell lines using
semi-quantitative reverse-transcription PCR, and detected PTPN12 protein expression using immunohistochemistry in 150
primary invasive breast cancer cases...
Tipo: Journal article
Palavras-chave: Breast cancer; Tumor suppressor gene; PTPN12; Prognosis; Methylation.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200033
Colorectal cancer DNA methylation patterns from patients in Manaus, Brazil
Provedor de dados: 48
Autores: Almeida,Fabiana Greyce Oliveira; Aquino,Priscila Ferreira de; Souza,Afonso Duarte Leäo de; Souza,Antonia Queiroz
Lima de; Vinhote,Sonia do Carmo; Mac-Cormick,Thais Messias; Silva,Marcelo Soares da Mota; Chalub,Sidney Raimundo Silva;
Fischer,Juliana de Saldanha da Gama; Carvalho,Paulo Costa; Carvalho,Maria da Gloria da Costa.
BACKGROUND: DNA methylation is commonly linked with the silencing of the gene expression for many tumor suppressor
genes. As such, determining DNA methylation patterns should aid, in times to come, in the diagnosis and personal treatment for
various types of cancers. Here, we analyzed the methylation pattern from five colorectal cancer patients from the Amazon state in
Brazil for four tumor suppressor genes, viz.: DAPK, CDH1, CDKN2A, and TIMP2 by employing a polymerase chain reaction
(PCR) specific to methylation. Efforts in the study of colorectal cancer are fundamental as it is the third most of highest incidence
in the world. RESULTS: Tumor biopsies were methylated in 1/5 (20 %), 2/5 (40 %), 4/5 (80 %), and 4/5 (80 %) for CDH1,
CDKN2A, DAPK, and TIMP2...
Tipo: Journal article
Palavras-chave: Methylation; Colorectal cancer; Amazon; Epigenetic.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602015000100050
Constitutional and somatic methylation status of DMRH19 and KvDMR in Wilms tumor patients
Provedor de dados: 74
Autores: Cardoso,Leila C.A.; Castaño,Jair A. Tenorio; Pereira,Hanna S.; Lima,Maria Angélica de F.D.; Santos,Anna Cláudia E.
dos; Faria,Paulo S. de; Ferman,Sima; Seuánez,Héctor N.; Nevado,Julián B.; Almeida,José Carlos Cabral de; Lapunzina,Pablo;
Vargas,Fernando R.
The most frequent epigenetic alterations in Wilms tumor (WT) occur at WT2, assigned to 11p15. WT2 consists of two domains:
telomeric domain 1 (DMRH19) that contains the IGF2 gene and an imprinted maternally expressed transcript (H19) and
centromeric domain 2 (KvDMR) that contains the genes KCNQ1, KCNQ1OT1 and CDKN1C. In this work, we used
pyrosequencing and MS-MLPA to compare the methylation patterns of DMRH19/KvDMR in blood and tumor samples from 40
WT patients. Normal constitutional KvDMR methylation indicated that most of the epigenetic alterations in WT occur at
DMRH19. Constitutional DMRH19 hypermethylation (HM DMRH19) was observed in two patients with Beckwith-Wiedemann
syndrome. Pyrosequencing and MS-MLPA showed HM DMRH19 in 28/34 tumor samples:...
Tipo: Journal article
Palavras-chave: Epigenetic; Histopathology; Methylation; MS-MLPA; Pyrosequencing.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000500002
DNA demethylation during Chrysanthemum floral transition following short-day treatment
Provedor de dados: 69
Autores: Li,Zhongai; Li,Jie; Yanhua,Liu; Wang,Zicheng.
Background: Analytical techniques such as methylation-sensitive amplification polymorphism and high-performance liquid
chromatography were used to detect variation in DNA methylation of mature Chrysanthemum leaves during the floral transition
induced by short-day (SD) treatment. Results: For both early- and late-flowering cultivars, the time from the date of planting to
the appearance of the capitulum bud and early blooming were significantly shorter than those of the control. The capitulum
development of the early-flowering cultivar was significantly accelerated compared to the control, unlike the late-flowering
cultivar. The DNA methylation percentage of leaves was significantly altered during flower development. For the early-flowering
cultivar, DNA...
Tipo: Journal article
Palavras-chave: Chrysanthemum; DNA; Methylation; Floral transition; Short day.
Ano: 2016
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000300009
DNA methylation patterns of candidate genes regulated by thymine DNA glycosylase in patients with
TP53 germline mutations
Provedor de dados: 56
Autores: Fortes,F.P.; Kuasne,H.; Marchi,F.A.; Miranda,P.M.; Rogatto,S.R.; Achatz,M.I.
Li-Fraumeni syndrome (LFS) is a rare, autosomal dominant, hereditary cancer predisposition disorder. In Brazil, the p.R337H
TP53 founder mutation causes the variant form of LFS, Li-Fraumeni-like syndrome. The occurrence of cancer and age of disease
onset are known to vary, even in patients carrying the same mutation, and several mechanisms such as genetic and epigenetic
alterations may be involved in this variability. However, the extent of involvement of such events has not been clarified. It is well
established that p53 regulates several pathways, including the thymine DNA glycosylase (TDG) pathway, which regulates the
DNA methylation of several genes. This study aimed to identify the DNA methylation pattern of genes potentially related to the
TDG...
Tipo: Journal article
Palavras-chave: Li-Fraumeni syndrome; TP53 gene; TDG; Methylation.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000700610
DNA methylation regulates expression of VEGF-C, and S-adenosylmethionine is effective for
VEGF-C methylation and for inhibiting cancer growth
Provedor de dados: 56
Autores: Da,M.X.; Zhang,Y.B.; Yao,J.B.; Duan,Y.X.
DNA hypomethylation may activate oncogene transcription, thus promoting carcinogenesis and tumor development.
S-adenosylmethionine (SAM) is a methyl donor in numerous methylation reactions and acts as an inhibitor of intracellular
demethylase activity, which results in hypermethylation of DNA. The main objectives of this study were to determine whether
DNA hypomethylation correlated with vascular endothelial growth factor-C (VEGF-C) expression, and the effect of SAM on
VEGF-C methylation and gastric cancer growth inhibition. VEGF-C expression was assayed by Western blotting and RT-qPCR in
gastric cancer cells, and by immunohistochemistry in tumor xenografts. VEGF-C methylation was assayed by bisulfite DNA
sequencing. The effect of SAM on cell apoptosis was...
Tipo: Journal article
Palavras-chave: VEGF-C; Methylation; S-adenosylmethionine; Gastric cancer.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014001201021
Epigenetic alterations in human brain tumors in a Brazilian population
Provedor de dados: 74
Autores: Anselmo,Nilson Praia; Bello,Maria Josefa; Gonzalez-Gomez,Pilar; Dias,Luis Antonio Araújo; Almeida,José Reinaldo
Walter de; Santos,Marcelo José dos; Rey,Juan A.; Casartelli,Cacilda.
Aberrant methylation of CpG islands located in promoter regions represents one of the major mechanisms for silencing
cancer-related genes in tumor cells. We determined the frequency of aberrant CpG island methylation for several tumor-associated
genes: DAPK, MGMT, p14ARF, p16INK4a, TP73, RB1 and TIMP-3 in 55 brain tumors, consisting of 26 neuroepithelial tumors,
6 peripheral nerve tumors, 13 meningeal tumors and 10 metastatic brain tumors. Aberrant methylation of at least one of the seven
genes studied was detected in 83.6% of the cases. The frequencies of aberrant methylation were: 40% for p14ARF, 38.2% for
MGMT, 30.9% for, p16INK4a, 14.6% for TP73 and for TIMP-3, 12.7% for DAPK and 1.8% for RB1. These data suggest that the
hypermethylation observed in...
Tipo: Journal article
Palavras-chave: Brain tumors; Epigenetics; Methylation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000300001
High frequency of p 16 promoter methylation in non-small cell lung carcinomas from Chile
Provedor de dados: 48
Autores: GUZMAN,LEDA M; KORIYAMA,CHIHAYA; AKIBA,SUMINORI; EIZURU,YOSHITO; CASTILLO,DARWINS;
CORVALAN,ALEJANDRO; AGUAYO,FRANCISCO R.
The inactivation of tumour suppressor genes by aberrant methylation of promoter regions has been described as a frequent event
in neoplasia development, including lung cancer. The p16 gene is a tumour suppressor gene involved in the regulation of cell
cycle progression that has been reported to be inactivated by promoter methylation in lung carcinomas at variable frequencies
around the world in a smoking habit dependent manner. The purpose of this study was to investigate the methylation status of the
promoter region of the p16 gene in 74 non-small cell lung carcinomas from Chile. The frequency of p16 gene inactivation by
promoter methylation was determined as 79.7% (59/74). When we considered histological type, we observed that p16 promoter
methylation...
Tipo: Journal article
Palavras-chave: Lung carcinoma; Methylation; Promoter region.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602007000400011
Methylation-specific PCR analysis in Col8A1 promoter in Creole cattle carrier of rob(1;29)
Provedor de dados: 69
Autores: Postiglioni,Alicia; García,Cristina B; Rincón,Gonzalo; Arruga,M. Victoria.
Robertsonian translocation (rob(1;29)) is the most frequent structural chromosomal abnormality in cattle. Heterozygous carriers
have a normal phenotype but show a 3-5% decrease in fertility. Chromatin decondensation was evaluated similar to the inactive X
chromosome when submitted to demethylating agent. Based on this result, and the concept that imprinted genes are essential in
embryonic development, we decided to query genes located on BTA1 and BTA29 that could undergo genome imprinting. The
collagen typeVIII-α1 (Col8A1) acted on extracellular matrix structural proteins. DNA bisulfite conversion and sequentiation
methods were used to compare its differential methylation patterns. It was performed on eight Creole cattle DNA blood samples
from normal and...
Tipo: Journal article
Palavras-chave: Bisulfite; Collagen; Creole cattle; Cytosines; Methylation.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000300013
Placental hydroxymethylation vsmethylation at the imprinting control region 2 on chromosome
11p15.5
Provedor de dados: 56
Autores: Magalhães,H.R.; Leite,S.B.P.; Paz,C.C.P. de; Duarte,G.; Ramos,E.S.
In addition to methylated cytosines (5-mCs), hydroxymethylcytosines (5-hmCs) are present in CpG dinucleotide-enriched regions
and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene
expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic
digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene
regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an
imprinting control region (ICR2) that includes a differentially methylated region (KvDMR1) that guarantees parent-specific gene
expression. The...
Tipo: Journal article
Palavras-chave: Methylation; Hydroxymethylation; Placenta; Genomic Imprinting; ICR2; KvDMR1.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013001100916
Study of Methylation Pattern of de Novo DNA Methyltransferase Genes and its Correlation with DNA
Methylation Pattern of RUNX3 in Individuals with Gastric Cancer from Northern Region of Brazil
Provedor de dados: 77
Autores: Lima,Eleonidas Moura; Leal,Mariana Ferreira; Motta,Fábio José Nascimento; Assumpção,Paulo Pimentel de;
Harada,Maria Lucia; Smith,Marilia de Arruda Cardoso; Burbano,RommelRodríguez; Casartelli,Cacilda.
Gastric cancer is the forth malignancy in frequency in the world. In the northern Brazil is the second neoplasia most frequent in
males and the third most frequent in females. Genetic and epigenetic alterations are evolved on gastric carcinogenesis and DNA
methylation is the epigenetic alteration better studied. We analyzed de novo DNA methyltransferases methylation pattern and its
association with RUNX3 gene methylation pattern in Brazilian samples of intestinal-type and diffuse-type of gastric cancer. PCR
methylation specific was used to evaluate DNA methylation pattern. Sixty-six samples were studied in this work. Only the gene
RUNX3 presented altered methylation pattern, being methylated in 38.5% of gastric cancer intestinal-type samples and in 70%
of...
Tipo: Journal article
Palavras-chave: Methylation; De novo DNA methyltransferases; RUNX3; Gastric cancer.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022007000400022