DNA methylation analysis of malignant and normal uveal melanocytes reveals novel molecular features of uveal melanoma
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE200316 | GEO | 2023/08/21
REPOSITORIES: GEO
Similar Datasets
Project description:DNA methylation profiling of NeuN+sorted neuronal nuclei from post-mortem brain tissue of Multiple Sclerosis (MS) patients (n=10) (MS) and non-neurological controls (n=7) (non-MS). Genomic DNA was subjected to conventional BS-treatment as well as oxidative BS (oxBS)-conversion using TrueMethylTM 96 kit of CEGXTM (Cambridge Epigenetix Limited) to allow for subsequent detection of hydroxymethylation (5hmC = BS - oxBS).
2019-06-21 | GSE119532 | GEO
Project description:Aim: Tandem bisulfite (BS) and oxidative bisulfite (oxBS) conversion on DNA followed by hybridization to Infinium HumanMethylation BeadChips allows nucleotide resolution of 5-hydroxymethylcytosine genome-wide. Here, the authors compared data quality acquired from BS-treated and oxBS-treated samples. Materials & methods: Raw BeadArray data from 417 pairs of samples across 12 independent datasets were included in the study. Probe call rates were compared between paired BS and oxBS treatments controlling for technical variables. Results: oxBS-treated samples had a significantly lower call-rate. Among technical variables, DNA-specific extraction kits performed better with higher call rates after oxBS conversion. Conclusion: The authors emphasize the importance of quality control during oxBS conversion to minimize information loss and recommend using a DNA-specific extraction kit for DNA extraction and an oxBSQC package for data preprocessing.
2022-01-14 | GSE182919 | GEO
Project description:Background: 5-methylcytosine (5-mC) and its oxidized form, 5-hydroxymethylcytosine (5-hmC), are distinct epigenetic marks that help regulate gene expression in the mammalian brain. Existing studies have identified associations between 5-mC and neurodegenerative disease, but little work has examined the potential role of 5-hmC in Parkinson’s disease (PD) or Alzheimer’s disease (AD). Here, we utilized PD postmortem brain tissue and a public dataset from postmortem AD brains to analyze the effect of neurodegenerative disease on paired 5-mC and 5-hmC levels. Results: In PD samples, we measured genome-wide 5-mC and 5-hmC from control (n=3) and PD (n=6) brains using the Illumina EPIC array combined with bisulfite and oxidative bisulfite treatments (BS/oxBS-EPIC). In publicly sourced data, genome-wide 5-mC and 5-hmC were measured from control (n=25) and AD (n=62) human entorhinal cortex tissue using the Illumina 450K array combined with bisulfite and oxidative bisulfite treatment (BS/oxBS-450K). Paired 5-mC and 5-hmC beta values were generated using a custom pipeline of bioinformatics tools, and we modeled the effect of disease on paired 5-mC and 5-hmC data using a mixed effects beta regression model with a random effect for ID and an interaction term between disease category and DNA modification category (“5-mC” or “5-hmC”). We identified a number of CpG probes (AD: n=699, PD: total n = 80) that showed a significant interaction between disease status and DNA modification category (p-value < 2.4x10-7). Conclusions: While our PD data requires additional validation, our analyses suggest that there are widespread shifts in the balance between 5-mC and 5-hmC in Parkinson’s and Alzheimer’s disease.
2019-10-09 | GSE138597 | GEO
Project description:Genome wide DNA methylation profilings (Bisulfite (BS), or oxidative bisulfite (oxBS)) were done for A2780 cells 1) infected with control virus, no H2O2 (Scr_mock) treatment, 2) infected with control virus with H2O2 treatment (30 min plus 2.5 h resting) (Scr_H2O2), and 3) infected with shTET2 virus, with H2O2 treatment (30 min plus 2.5 h resting) (shTET2_H2O2). Each genomic DNA was splitted equally to two aliquots. One aliquote was subjected to oxidation (oxBS) and one to mock oxidation (BS) prior to bisulfite treatment (CEGX protocol). The Illumina’s Infinium Human Methylation450 Beadchip Kit (WG-314-1001) was used to obtain DNA methylation profiles across approximately 450,000 CpGs. 5hmC levels were calculated by subtracting oxBS values from BS values.
2016-12-31 | GSE83750 | GEO
Project description:A. flavus keratitis is one of the predominant fungal infections affecting the tropical parts of the world. Melanin is a virulence factor in numerous pathogenic fungi and the melanin layer maintains the cell wall structure and provides chemical and physical protection to the organism. However, the molecular and biological mechanisms modulating melanin-mediated host-pathogen interaction in A. flavus keratitis are not well understood. This work aimed to compare the morphology, surface proteome profile and virulence of melanized and non-melanized conidia of A. flavus. An environmental isolate and two clinical isolates were included in this study. L-DOPA melanin pathway-specific inhibitor kojic acid (KA) as used to prepare non-melanized conidia. Conidial surface proteins were extracted using 100% formic acid at 0 ºC and the extracted proteins were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS PAGE). Formic acid extracts were analyzed in an Orbitrap Velos pro-mass spectrometer. Conidial surface morphology difference was examined using scanning electron microscopy (SEM). Furthermore, lactophenol and calcofluor staining were performed to check the morphology and staining efficiency of melanized conidia (MC) and non-melanized conidia (NMC). A Galleria mellonella insect model was used to examine the virulence efficiency of MC and NMC. Kojic acid treatment inhibited melanin synthesis in A. flavus and the conidial surface protein profile was significantly different in kojic acid-treated non-melanized conidia. Several cell wall-associated proteins and proteins responsible for oxidative stress, carbohydrate, and chitin metabolic pathway were found only in the formic acid extracts of NMC. SEM analysis showed the conidial surface morphology difference between the NMC and MC indicating the role of melanin in the structural integrity of the conidial cell wall. The levels of calcofluor staining efficiency were different, but there was no microscopic morphology difference in lactophenol cotton blue staining of MC and NMC. Evaluation of virulence of MC and NMC in G. mellonella model showed NMC was less virulent compared to MC . Our results showed that the integrity of the conidial surface is controlled by the melanin layer. The alteration in the surface protein profile indicated that many surface proteins are masked by the melanin layer and hence melanin can modulate the host response by preventing the exposure of fungal proteins to the host immune defense system. G. mellonella in vivo virulence assay also confirmed that the non-melanized conidia were susceptible to host defense as in other Aspergillus pathogens.
2024-05-23 | PXD037707 | Pride
Project description: Not available
| S-ECPF-GEOD-44299 | biostudies-other
Project description:PURPOSE: Tissue culture is traditionally performed at atmospheric oxygen concentration (21%), which induces hyperoxic stress, as endogenous physiologic oxygen tension found in tissues varies between 2% and 9%. This discrepancy may lead to misinterpretation of results and may explain why effects observed in vitro cannot always be reproduced in vivo and vice versa. Only a few studies have been conducted in low physiologic oxygen conditions to understand the development and differentiation of cells from the eye. METHODS: The aim of this study was to investigate the growth and gene expression profile of melanocytes from the choroid permanently exposed to 21% (hyperoxic) or 3% (physiologic) oxygen with proliferation assays and DNA microarray. The cellular behavior of the melanocytes was then compared to that of cancer cells. RESULTS: The gross morphology and melanin content of choroidal melanocytes changed slightly when they were exposed to 3% O2, and the doubling time was statistically significantly faster. There was an increase in the percentage of choroidal melanocytes in the active phases of the cell cycle as observed by using the proliferation marker Ki67. The caveolin-1 senescence marker was not increased in choroidal melanocytes or uveal melanoma cells grown in hyperoxia. In comparison, the morphology of the uveal melanoma cells was similar between the two oxygen levels, and the doubling time was slower at 3% O2. Surprisingly, gene expression profiling of the choroidal melanocytes did not reveal a large list of transcripts considerably dysregulated between the two oxygen concentrations; only the lactate transporter monocarboxylate transporter (MCT4) was statistically significantly upregulated at 3% O2. CONCLUSIONS: This study showed that the oxygen concentration must be tightly controlled in experimental settings, because it influences the subsequent cellular behavior of human choroidal melanocytes.
2016-09-10 | GSE86789 | GEO
Project description:Karyotyping by SNP array of primary uveal melanoma samples, uveal melanoma cell lines and normal controls The Human660WQuad v1.0 DNA Analysis Bead Chip and kit were used for high resolution molecular karyotyping of DNA isolated from snap-frozen primary uveal melanoma tissue isolated from enucleated eyes.
2013-02-14 | E-GEOD-44297 | biostudies-arrayexpress
Project description:To characterize the largely unknown functions of oxidised methylcytosines (oxi-mC; 5hmC/5fC/5caC) in DNA, several sequencing protocols have been recently developed. Quantitative analysis is complicated because DNA methylation modifications need to be deconvoluted from the data which is affected by several experimental parameters, including e.g. imperfect bisulphite conversion, oxidation efficiencies, various chemical labeling and protection steps, and sequencing errors. Here, we present a hierarchical generative model, Lux, for integrative analysis of any combination of BS-seq and âoxi-mCâ-seq (BS-seq/oxBS-seq/TAB-seq/fCAB-seq/CAB-seq/redBS-seq/MAB-seq) data. We show that Lux improves quantification and comparison of methylation levels over existing methods and that Lux can easily process any oxi-mC-seq data sets to quantify all cytosine modifications simultaneously together with their experimental parameters. Application of Lux to targeted data from Tet2 knockdown ESCs and T cells during development demonstrates DNA modification quantification at unprecedented detail, quantifies active demethylation pathway and reveals 5hmC localization in putative regulatory regions. Examine the distribution of C, 5mC, and 5hmC in ES and Tet2 knock-down cells within selected loci. Half of the samples are measured using the traditional bisulphite-seq protocol but the other half is measured using the oxidative bisulphite-seq protocol (oxBS-seq).
2016-07-03 | E-GEOD-68574 | biostudies-arrayexpress
Project description:To characterize the largely unknown functions of oxidised methylcytosines (oxi-mC; 5hmC/5fC/5caC) in DNA, several sequencing protocols have been recently developed. Quantitative analysis is complicated because DNA methylation modifications need to be deconvoluted from the data which is affected by several experimental parameters, including e.g. imperfect bisulphite conversion, oxidation efficiencies, various chemical labeling and protection steps, and sequencing errors. Here, we present a hierarchical generative model, Lux, for integrative analysis of any combination of BS-seq and âoxi-mCâ-seq (BS-seq/oxBS-seq/TAB-seq/fCAB-seq/CAB-seq/redBS-seq/MAB-seq) data. We show that Lux improves quantification and comparison of methylation levels over existing methods and that Lux can easily process any oxi-mC-seq data sets to quantify all cytosine modifications simultaneously together with their experimental parameters. Application of Lux to targeted data from Tet2 knockdown ESCs and T cells during development demonstrates DNA modification quantification at unprecedented detail, quantifies active demethylation pathway and reveals 5hmC localization in putative regulatory regions. Examine the distribution of C, 5mC, and 5hmC in DP, CD4 SP, and naïve CD4 T cells within selected loci. Half of the samples are measured using the traditional bisulphite-seq protocol but the other half is measured using the oxidative bisulphite-seq protocol (oxBS-seq).
2016-07-03 | E-GEOD-68575 | biostudies-arrayexpress