Primary uveal melanoma cells, normal uveal melanocytes, neural crest stem cells, embryonic stem cells and uveal melanoma cell lines
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Li Zhang
PROVIDER: E-GEOD-44299 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Preeclampsia is one of the leading causes of maternal death worldwide. While the root cause is still unknown, the underlying biology of the disorder is becoming more clear. We recently published a study showing large, significant differences in DNA methylation in 3rd trimester placental samples associated with early-onset preeclampsia (EOPET) compared to controls. In this study, to identify DNA methylation differences associated with preeclampsia that occur early in pregnancy and to further delineate common EOPET-associated differences, we utilized a genetic defect, trisomy 16 (T16), that is predisposing to preeclampsia. We ran T16 placental samples from the 1st trimester (n=5) and 3rd trimester (n=10) against gestational age matched controls on the Illumina Infinium HumanMethylation450 BeadChip. Third trimester samples were from pregnancies with T16 confined to the placenta (confined placental mosaicism 16;CPM16), and consisted of samples that were and were not associated with EOPET (n=5 each). We identified a large number of DNA methylation differences in CPM16 samples compared to controls using stringent criteria (n=2254;False Discovery Rate <0.01, ->0.15). Several of these differences (11%) overlapped differences observed in chromosomally normal EOPET using similarly stringent criteria (FDR<0.01;->0.125). Isolating EOPET-associated probes produced a similar - distribution amongst CPM16 samples, although samples associated with EOPET showed a tendency towards larger DNA methylation differences. We also identified 262 DNA methylation differences between 1st trimester T16 and 1st trimester controls. Of these, 77 overlapped differences seen in 3rd trimester CPM16. Investigating these 77 T16/CPM16 specific DNA methylation differences, we identified three probes near two genes (ARGHEF37 and JUNB) that were also present as EOPET-associated methylation differences. In summary, we identified significant overlapping DNA methylation profiles of placentas with T16 and chromosomally normal placentas associated with EOPET. Specific DNA methylation marks within these profiles may be of future clinical utility in early identification of pregnancies susceptible to EOPET. Bisulfite converted DNA from 5 1st trimester trisomy 16 placentas, 5 chromosomally normal 1st trimester placentas, 10 third trimester placentas from confined placental mosaicism placentas and 10 chromosomally normal 3rd trimester placentas
2014-01-15 | E-GEOD-49343 | biostudies-arrayexpress
Project description:Background: Measurement of genome-wide DNA methylation (DNAm) has become an important avenue for investigating potentially functional changes in various pathological conditions. Illumina Infinium is a relatively inexpensive and user-friendly DNAm microarray platform used by many researchers to measure DNAm on a large scale. However it has been suggested that a subset of probes may give rise to misleading results due to issues related to probe design. To facilitate biologically significant data interpretation, we set out to enhance probe annotation of the newest HumanMethylation450 BeadChip array (with >485,000 probes covering 99% of RefSeq genes). Results: Annotation that was added or expanded on includes 1) SNPs documented in the probe target, 2) probe binding specificity, 3) CpG classification of target sites and 4) gene feature classification of target sites. Probes with documented SNPs within 10bp of the target site and especially those with documented SNPs at the target CpG, were associated with increased within-tissue variation in DNAm. An example of a probe with a SNP at the target CpG was used to demonstrate how sample genotype can confound the measurement of DNAm. 8.6% of probes were identified as non-specific, in other words, these probes map to multiple locations in silico. DNAm measured from these non-specific probes likely represents a combination of DNAm from multiple genomic sites. The expanded biological annotation demonstrated that based on DNAm, grouping probes by alternative CpG classes rather than UCSC islands provides a more distinctive classification system of CpG sites. Finally variable enrichment for tissue-specific differentially methylated probes was noted across CpG classes and gene feature groups, depending on the tissues that were compared. Conclusion: Probes containing SNPs and non-specific probes may affect the assessment of DNAm using the 450k array. Additionally CpG enrichment classes and to a lesser extent gene feature groups were associated with distinct patterns of DNAm. Thus, we recommend that confounded probes be removed from analyses and that genomic trends be considered in analyses of the Illumina HumanMethylation450 BeadChip. DNAm arrays offer a powerful approach for which thoughtful use of probe content can be utilized to better understand the biological processes affected. Bisulfite converted DNA from 4 buccal, 4 blood and 4 chorionic villus samples was hybridized to the Illumina Infinium HumanMethylation450 BeadChip array.
2013-03-04 | E-GEOD-42409 | biostudies-arrayexpress
Project description:Baseline study to investigate methylation patterns in differentiated cells. profiling of two differentiated cell types
2013-04-26 | E-GEOD-40790 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE36857: Goldengate Methylation analysis: Ewing Sarcoma GSE36858: 5- AZA treatment of EWS cell lines Refer to individual Series
2012-09-01 | E-GEOD-36859 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2016-04-01 | E-GEOD-67771 | biostudies-arrayexpress
Project description:Genome wide DNA methylation profiling of fetal DNA-methylation levels in 47 chorionic villi (CVS) and 16 amniotic cell (AC) samples. The Illumina Infinium 27k Human DNA methylation Beadchip was used to determine DNA methylation profiles across approximately 27,578 CpGs in fetal samples. Bisulphite converted DNA from the 61 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip (2 sample in duplicate pairs)
2012-12-14 | E-GEOD-35327 | biostudies-arrayexpress
Project description:Monozygotic twins discordant for type 2 diabetes constitute an ideal model to study environmental contributions to type 2 diabetic traits. We aimed to examine whether global DNA methylation differences exist in major glucose metabolic tissues from twelve 53–80 year-old monozygotic discordant twin pairs. DNA methylation was measured by the Illumina HumanMethylation27 BeadChip in 22 (11 pairs) skeletal muscle and 10 (5 pairs) subcutaneous adipose tissue biopsies. No replicates were included.
2012-12-10 | E-GEOD-38291 | biostudies-arrayexpress
Project description:Gene expression in primary uveal melanoma cells and normal cell controls The HumanHT-12 v3 gene expression microarray (Illumina) was used to analyze RNA isolated from snap-frozen primary uveal melanoma tissue isolated from enucleated eyes and from normal cell controls.
2013-02-14 | E-GEOD-44295 | biostudies-arrayexpress
Project description:Genome wide DNA methylation profiling of primary uveal melanoma cells, normal uveal melanocytes, neural crest stem cells, embryonic stem cells and uveal melanoma cell lines. The Illumina Infinium 27k Human DNA methylation Beadchip Rev B was used to obtain DNA methylation profiles across approximately 27,000 CpGs in the samples. Samples included 58 primary UM, 3 NUM and NCSC controls and 2 cell lines. Bisulphite converted DNA from the 63 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip Rev B
2013-02-14 | E-GEOD-44296 | biostudies-arrayexpress
Project description:TET2 is a close relative of TET1, an enzyme that converts 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in DNA. The gene encoding TET2 resides at chromosome 4q24, in a region showing recurrent microdeletions and copy-neutral loss of heterozygosity (CN-LOH) in patients with diverse myeloid malignancies. Somatic TET2 mutations are frequently observed in myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), MDS/MPN overlap syndromes including chronic myelomonocytic leukaemia (CMML), acute myeloid leukaemias (AML) and secondary AML (sAML). We show here that TET2 mutations associated with myeloid malignancies compromise catalytic activity. Bone marrow samples from patients with TET2 mutations displayed uniformly low levels of 5hmC in genomic DNA compared to bone marrow samples from healthy controls. Moreover, small hairpin RNA (shRNA)-mediated depletion of Tet2 in mouse haematopoietic precursors skewed their differentiation towards monocyte/macrophage lineages in culture. There was no significant difference in DNA methylation between bone marrow samples from patients with high 5hmC versus healthy controls, but samples from patients with low 5hmC showed hypomethylation relative to controls at the majority of differentially methylated CpG sites. Our results demonstrate that Tet2 is important for normal myelopoiesis, and suggest that disruption of TET2 enzymatic activity favours myeloid tumorigenesis. Measurement of 5hmC levels in myeloid malignancies may prove valuable as a diagnostic and prognostic tool, to tailor therapies and assess responses to anticancer drugs. Genome wide DNA methylation profiling of patients samples with various myeloid malignancies and diffrential levels of 5hmC.The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in bone marrow samples and occasionally peripheral blood samples. Samples included 28 control healthy bone marrows, 29 patients samples with low 5hmC levels (7 patients with wild-type TET2 and 22 mutant TET2) and 24 with high levels of 5hmC (22 with wild-type TET2 and 2 mutant TET2). Bisulphite converted DNA from 81 samples was hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2
2010-12-11 | E-GEOD-25706 | biostudies-arrayexpress