Search results for " methylation"
showing 10 items of 457 documents
dsDNA, ssDNA, G-quadruplex DNA, and nucleosomal DNA electrochemical screening using canthin-6-one alkaloid-modified electrodes
2014
Abstract Microparticulate films of a canthin-6-one alkaloid ( L ), a natural β-carboline alkaloid presenting a characteristic naphtyridone motif, on glassy carbon electrodes yield different, separate voltammetric signals for dsDNA, ssDNA, G-quadruplex DNA, different degrees of DNA methylation and the biomimetic nucleosomal DNA with detection limit of 10 −5 M. This multiple-signal electrochemical behavior is in contrast with conventional use of DNA intercalators, only discriminating between different DNA forms by variations in the intensity of a unique signal. Complementary photochemical and scanning electrochemical microscopy (SECM) data suggest that the differences in the voltammetric res…
Zwitterionic Sulfonates as m/z Shift Reagents for 5-Methylcytosine Detection in Deoxyribonucleic Acids (DNA) Using Flow Injection Analysis and Electr…
2015
5-Methylcytosine (5-MC) is an important epigenetic modification of DNA. Abnormally high concentrations of this substance appear because of the hypermethylation of cytosine. Therefore, the measurement of the quantity of this compound in mammals is of great importance. Recently, we reported that several imidazolium-based zwitterionic sulfonates form complexes with 5-MC in solution, which can be studied by electrospray ionisation mass spectrometry (ESI-MS). It is shown in this paper that such an association can be utilised for the detection of 5-MC in a DNA sample using high-throughput a flow injection analysis ESI-MS method. A variety of the sulfonate zwitterions have been tested as m/ z shi…
Methyl-CpG-binding domain sequencing reveals a prognostic methylation signature in neuroblastoma
2016
Accurate assessment of neuroblastoma outcome prediction remains challenging. Therefore, this study aims at establishing novel prognostic tumor DNA methylation biomarkers. In total, 396 low- and high-risk primary tumors were analyzed, of which 87 were profiled using methyl-CpG-binding domain (MBD) sequencing for differential methylation analysis between prognostic patient groups. Subsequently, methylation-specific PCR (MSP) assays were developed for 78 top-ranking differentially methylated regions and tested on two independent cohorts of 132 and 177 samples, respectively. Further, a new statistical framework was used to identify a robust set of MSP assays of which the methylation score (i.e.…
Prenatal exposure to mixtures of xenoestrogens and repetitive element DNA methylation changes in human placenta
2014
BACKGROUND: Prenatal exposure to endocrine disrupting compounds (EDCs) has previously shown to alter epigenetic marks. OBJECTIVES: In this work we explore whether prenatal exposure to mixtures of xenoestrogens has the potential to alter the placenta epigenome, by studying DNA methylation in retrotransposons as a surrogate of global DNA methylation. METHODS: The biomarker total effective xenoestrogen burden (TEXB) was measured in 192 placentas from participants in the longitudinal INMA Project. DNA methylation was quantitatively assessed by bisulfite pyrosequencing on 10 different retrotransposons including 3 different long interspersed nuclear elements (LINEs), 4 short interspersed nuclear …
DNA-methylation dependent regulation of embryo-specific 5S ribosomal DNA cluster transcription in adult tissues of sea urchin Paracentrotus lividus
2013
Abstract We have previously reported a molecular and cytogenetic characterization of three different 5S rDNA clusters in the sea urchin Paracentrotus lividus and recently, demonstrated the presence of high heterogeneity in functional 5S rRNA. In this paper, we show some important distinctive data on 5S rRNA transcription for this organism. Using single strand conformation polymorphism (SSCP) analysis, we demonstrate the existence of two classes of 5S rRNA, one which is embryo-specific and encoded by the smallest (700 bp) cluster and the other which is expressed at every stage and encoded by longer clusters (900 and 950 bp). We also demonstrate that the embryo-specific class of 5S rRNA is ex…
Constitutive Promoter Occupancy by the MBF-1 Activator and Chromatin Modification of the Developmental Regulated Sea Urchin α-H2A Histone Gene
2007
The tandemly repeated sea urchin alpha-histone genes are developmentally regulated. These genes are transcribed up to the early blastula stage and permanently silenced as the embryos approach gastrulation. As previously described, expression of the alpha-H2A gene depends on the binding of the MBF-1 activator to the 5' enhancer, while down-regulation relies on the functional interaction between the 3' sns 5 insulator and the GA repeats located upstream of the enhancer. As persistent MBF-1 binding and enhancer activity are detected in gastrula embryos, we have studied the molecular mechanisms that prevent the bound MBF-1 from trans-activating the H2A promoter at this stage of development. Her…
Functional interaction of estrogen receptor α and caveolin isoforms in neuronal SK-N-MC cells
2003
Estrogen receptors (ERs) are expressed in neuronal cells and exhibit a wide variety of activities in the central nervous system. The actions of ERs are regulated in a hormone-dependent manner as well as by a number of co-activators and -repressors. A recently identified co-activator of ERalpha is caveolin-1 which has been shown to mediate the ligand-independent activation of this steroid receptor. In the present study we have demonstrated that neuronal SK-N-MC cells lacking functional ERalpha show high levels of caveolin-1/-2 specific transcripts and proteins. Ectopic expression of ERalpha in SK-N-MC cells leads to the transcriptional suppression of caveolin-1 and -2 genes. This silencing e…
Molecular and Cellular Aspects of Chemical Carcinogenesis
1995
Different DNA-adducts produced by one given genotoxic agent can lead to different mutational preferences, as exemplified in this mini-review, by the cis-diamminedichloroplatinum(II)-induced d(GpG)-N7(1)-N7(2) adduct, giving rise predominantly to G→T transversions targeted to the 5′-modified G, the d(ApG)-N7(l)-N7(2) adduct to A→T transversions, while for the d(GpTpA)-N7(l)-N7(3) adduct no crosslink-specific mutations were observed. Expression of mutated Hras put under the control of cell-compartment specific promoters in different layers of the mouse skin showed that the consequent expression of the malignant phenotype depended on the degree of differentiation of the cell, progression to ca…
Epigenetic biomarkers for disease diagnosis
2019
Abstract Epigenetic dysregulation plays an important role in the initiation and progression of human diseases; therefore, because of the dynamic nature of this orchestrated regulation of epigenetic marks and epigenetic mechanisms, it is possible to use these marks as biomarkers. In this context, an epigenetic biomarker is “any epigenetic mark or altered epigenetic mechanism” which generally serves to evaluate health or disease status, progression or treatment response and is particularly stable and reproducible during sample processing. Advances in precision medicine, with better diagnostic and treatment strategies are the hope to improve the management of diseases, comorbidities, and morta…
Methylation status of VTRNA2-1/nc886 is stable across populations, monozygotic twin pairs and in majority of tissues. Supplementary data
2022
Supplementary Table 1. This study used 48 DNA methylation datasets, including DILGOM, FTC, ERMA, KORA, LURIC, NELLI, SATSA and YFS as well as 39 datasets available in the Gene Expression Omnibus (GEO) [29] consisting of >30 tissues and >30,000 individuals. Supplementary Table 2. Differences in the proportion of individuals with imprinted nc886 locus between sexes or in a case–control setting. Supplementary Table 3. Of these discordant pairs, one co-twin was always intermediately methylated, whereas the other co-twin was either imprinted or nonmethylated in all cases – that is, no twin pairs were identified in which one co-twin was imprinted and the other was nonmethylated. Supplementa…