Control of 5mC and 5hmC by TET dioxygenases in human embryonic carcinoma cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Keith Robertson
PROVIDER: E-GEOD-51903 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The TET family of dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), but their involvement in establishing normal 5mC patterns during mammalian development and their contributions to aberrant control of 5mC during cellular transformation remains largely unknown. We depleted TET1, TET2, and TET3 by siRNA in a pluripotent embryonic carcinoma cell model and examined the impact on genome-wide 5mC and 5hmC patterns. TET1 depletion yielded widespread reduction of 5hmC, while depletion of TET2 and TET3 reduced 5hmC at a subset of TET1 targets suggesting functional co-dependence. TET2 or TET3-depletion also caused increased 5hmC, suggesting they play a major role in 5hmC removal. All TETs prevent hypermethylation throughout the genome, a finding dramatically illustrated in CpG island shores, where TET depletion resulted in prolific hypermethylation. Surprisingly, TETs also promote methylation, as hypomethylation was associated with 5hmC reduction. TET function was highly specific to chromatin environment: 5hmC maintenance by all TETs occurred at polycomb-marked chromatin and genes expressed at moderate levels; 5hmC removal by TET2 is associated with highly transcribed genes enriched for H3K4me3 and H3K36me3. Importantly, genes prone to hypermethylation in cancer become depleted of 5hmC with TET deficiency, suggesting the TETs normally promote 5hmC at these loci, and all three TETs are required for 5hmC enrichment at enhancers, a condition necessary for expression of adjacent genes. These results provide novel insight into the division of labor among TET proteins and reveal an important connection of TET activity with chromatin landscape and gene expression. Affymetrix gene expression Human ST1.0 microarray of NCCIT human embryonic carcinoma cells (4 samples in duplicate).
2014-06-14 | E-GEOD-51901 | biostudies-arrayexpress
Project description:Global patterns of DNA methylation, mediated by the DNA methyltransferases (DNMTs), are disrupted in all cancers by mechanisms that remain largely unknown, hampering their development as therapeutic targets. Combinatorial acute depltion of all DNMTs in a pluripotent human tumor cell line, followed by epigenome and transcriptome analysis, revealed DNMT functions in unprecedented detail. DNMT3B occupancy regulates methylation during differentiation, while an unexpected interplay was discovered in which DNMT1 and DNMT3B antithetically regulate methylation and hydroxymethylation in gene bodies, a finding confirmed in other cell types. DNMT3B mediated nonCpG methylation, while DNMT3L influenced the activity of DNMT3B toward nonCpG versus CpG site methylation. Taken together, these data reveal new functional targets of each DNMT suggesting that isoform selective inhibition would be therapeutically advantageous. Affymetrix gene expression Human Gene 1.0 ST microarray of NCCIT human embryonic carcinoma cells (13 samples in duplicate).
2014-10-20 | E-GEOD-54841 | biostudies-arrayexpress
Project description:The TET family of dioxygenases catalyze conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), but their involvement in establishing normal 5mC patterns during mammalian development and their contributions to aberrant control of 5mC during cellular transformation remains largely unknown. We depleted TET1, TET2, and TET3 by siRNA in a pluripotent embryonic carcinoma cell model and examined the impact on genome-wide 5mC and 5hmC patterns. TET1 depletion yielded widespread reduction of 5hmC, while depletion of TET2 and TET3 reduced 5hmC at a subset of TET1 targets suggesting functional co-dependence. TET2 or TET3-depletion also caused increased 5hmC, suggesting they play a major role in 5hmC removal. All TETs prevent hypermethylation throughout the genome, a finding dramatically illustrated in CpG island shores, where TET depletion resulted in prolific hypermethylation. Surprisingly, TETs also promote methylation, as hypomethylation was associated with 5hmC reduction. TET function was highly specific to chromatin environment: 5hmC maintenance by all TETs occurred at polycomb-marked chromatin and genes expressed at moderate levels; 5hmC removal by TET2 is associated with highly transcribed genes enriched for H3K4me3 and H3K36me3. Importantly, genes prone to hypermethylation in cancer become depleted of 5hmC with TET deficiency, suggesting the TETs normally promote 5hmC at these loci, and all three TETs are required for 5hmC enrichment at enhancers, a condition necessary for expression of adjacent genes. These results provide novel insight into the division of labor among TET proteins and reveal an important connection of TET activity with chromatin landscape and gene expression. Methylation and hydroxymethylation profiling by affinity-based high throughput sequencing
2014-06-14 | E-GEOD-51902 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-10-20 | E-GEOD-54843 | biostudies-arrayexpress
Project description: Not available
| S-EPMC4993491 | biostudies-other
Project description:Global patterns of DNA methylation, mediated by the DNA methyltransferases (DNMTs), are disrupted in all cancers by mechanisms that remain largely unknown, hampering their development as therapeutic targets. Combinatorial acute depltion of all DNMTs in a pluripotent human tumor cell line, followed by epigenome and transcriptome analysis, revealed DNMT functions in unprecedented detail. DNMT3B occupancy regulates methylation during differentiation, while an unexpected interplay was discovered in which DNMT1 and DNMT3B antithetically regulate methylation and hydroxymethylation in gene bodies, a finding confirmed in other cell types. DNMT3B mediated nonCpG methylation, while DNMT3L influenced the activity of DNMT3B toward nonCpG versus CpG site methylation. Taken together, these data reveal new functional targets of each DNMT suggesting that isoform selective inhibition would be therapeutically advantageous. NCCIT cells were transfected with siRNAs against DNMT3B and a no-target control. Genomic DNA was extracted, and subsequently applied to affinity MBD-bound magnetic beads (Ribomed) to enrich methylated DNA sequences.
2014-10-20 | E-GEOD-54842 | biostudies-arrayexpress
Project description:We used microarrays to profile gene expression of NCCIT cells to study the link between epigenetic modifications and gene transcription. Extract total RNA to examine gene expression of NCCIT cells in the undifferentiated and differentiated states.
2012-10-19 | E-GEOD-38936 | biostudies-arrayexpress
Project description: Not available
| S-EPMC3491567 | biostudies-literature
Project description:DNA methylation mediated by the combined action of three DNA methyltransferases, DNMT1, DNMT3A, and DNMT3B, is essential for mammalian development and is also a major contributor to transformation. To elucidate how DNA methylation is targeted, we map the genome-wide localization of all DNMTs and methylation, and examine relationships between these markers and histone modifications and nucleosome structure. Our findings reveal a strong link between DNA methylation/DNMTs and transcribed loci and that these marks exhibit both overlapping and unique localization patterns. Comparisons with the epigenome of embryonic stem cells demonstrate that DNMT binding is associated with transformation-associated changes in methylation. Taken together, this study sheds important new light on determinants of DNA methylation and how it may become disrupted in cancer cells. Examination of different marks in undifferentiated and differentiatial NCCIT cells
2012-10-19 | E-GEOD-38937 | biostudies-arrayexpress
Project description:Tumor cells have an increased need for amino acids. Mammalian cells cannot synthesize essential amino acids; they must obtain these amino acids via specific transporters. Glutamine, though a non-essential amino acid, is critical for tumor cells (glutamine addiction). Entry of amino acids into tumor cells is enhanced by upregulation of specific transporters. If the transporters that are specifically induced in tumor cells are identified, blockade of the induced transporters would constitute a logical strategy for cancer treatment. The transporter SLC6A14 is unique and transports all essential amino acids as well as glutamine and is expressed only at low levels in normal tissues, but induced in colon cancer and in ER+ breast cancer. We have now established the potential of this transporter as a drug target for breast cancer treatment using genetic and pharmacologic approaches. We then examined the progression of breast cancer in Polyoma middle T antigen (Py-MT) Tg mouse on Slc6a14+/+ and Slc6a14-/- background using microarray analysis. We have used three Affy-chips for each tumor sample (Group 1: WT/PyMT; Group 2: Slc6a14-KO/PyMT). Three biological replicates were used for each group.
2015-08-05 | E-GEOD-56612 | biostudies-arrayexpress