This SuperSeries is composed of the SubSeries listed below.
Impact of human MLL/COMPASS and polycomb complexes on the DNA methylome.
Specimen part, Cell line
View SamplesThe association of DNA CpG methylation (or its absence) with occupancy of histone post translational modifications has hinted at an underlying crosstalk between histone marks and DNA methylation in patterning the human methylome, an idea supported by corresponding alterations to both histone marks and DNA methylation during malignant transformation. This study investigated the framework by which histone marks influence DNA methylation. Using RNAi in a human pluripotent embryonic carcinoma cell line we depleted essential components of the histone modifying complexes that establish the posttranslational modifications H3K4me3, H3K27me3, and H2AK119ub, and we assayed the impact of the subsequent loss of these marks on the DNA methylome. Absence of H2AK119ub resulted predominantly in hypomethylation across the genome. Removal of H3K4me3 or, surprisingly, H3K27me3 caused CpG island hypermethylation at a subset of loci. Intriguingly, many promoters were co-regulated by all three histone marks, becoming hypermethylated with loss of H3K4me3 or H3K27me3 and becoming hypomethylated with depletion of H2AK119ub, and many of these co-regulated loci were among those that are commonly, aberrantly hypermethylated in cancer.
Impact of human MLL/COMPASS and polycomb complexes on the DNA methylome.
Specimen part, Cell line
View SamplesWe have identified the transcription factor forkhead box protein F2 (Foxf2) to be upregulated in its expression during the EMT process and studied its functional contribution to EMT by siRNA-mediated knockdown in NMuMG cells treated for 4 days with TGFbeta followed by mRNA-sequencing. Our analysis revealed a dual role of Foxf2 during TGFbeta-induced EMT in promoting apoptosis while inducing cell junction breakdown and migration. Overall design: mRNA sequencing of NMuMG/E9 cells transfected with control siRNA or Foxf2 specific siRNA and treated with TGFbeta for 4 days
Foxf2 plays a dual role during transforming growth factor beta-induced epithelial to mesenchymal transition by promoting apoptosis yet enabling cell junction dissolution and migration.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Distinct and overlapping control of 5-methylcytosine and 5-hydroxymethylcytosine by the TET proteins in human cancer cells.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Nucleosome positioning changes during human embryonic stem cell differentiation.
Specimen part, Cell line
View SamplesThe 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.
Distinct and overlapping control of 5-methylcytosine and 5-hydroxymethylcytosine by the TET proteins in human cancer cells.
Specimen part, Cell line
View SamplesNucleosomes are the basic unit of chromatin. Nucleosome positioning (NP) plays a key role in transcriptional regulation and other biological processes. To better understand NP we used MNase-seq to investigate changes that occur as human embryonic stem cells (hESCs) transition to nascent mesoderm and then to smooth muscle cells (SMCs). Compared to differentiated cell derivatives, nucleosome occupancy at promoters and other notable genic sites, such as exon/intron junctions and adjacent regions, in hESCs shows a stronger correlation with transcript abundance and is less influenced by sequence content. Upon hESC differentiation, genes being silenced, but not genes being activated, display a substantial change in nucleosome occupancy at their promoters. Genome-wide, we detected a shift of NP to regions of higher G+C content as hESCs differentiate to SMCs. Notably, genomic regions with higher nucleosome occupancy harbor twice as many GC changes but fewer than half AT changes, compared to regions with lower nucleosome occupancy. Finally, our analysis indicates that the hESC genome is not rearranged and has a sequence mutation rate resembling normal human genomes. Our study reveals another unique feature of hESC chromatin, and sheds light on the relationship between nucleosome occupancy and sequence G+C content.
Nucleosome positioning changes during human embryonic stem cell differentiation.
Specimen part, Cell line
View SamplesWe used microarrays to develop gene signatures for XBP1 and IRE1 in myeloma cells to explore the role of this UPR/differentiation pathway in proteasome inhibitor resistance.
Xbp1s-negative tumor B cells and pre-plasmablasts mediate therapeutic proteasome inhibitor resistance in multiple myeloma.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Linking DNA methyltransferases to epigenetic marks and nucleosome structure genome-wide in human tumor cells.
Specimen part, Cell line
View SamplesWe investigated the effect of miR-1199-5p, miR-200b-3p and miR-429-3p on gene expression profiles during TGFbeta-induced EMT in normal murine mammary gland cells by using the mRNA-sequencing. Our analysis demonstrates that miR-1199-5p and both miR-200 family members share only 6 target genes, indicating that besides regulating Zeb1 expression they exert distinct functions during EMT. Overall design: mRNA profiles of NMuMG cells transiently overexpressing miR-1199-5p, miR-200b-3p or miR-429-3p and treated with TGFbeta for 4 days
miR-1199-5p and Zeb1 function in a double-negative feedback loop potentially coordinating EMT and tumour metastasis.
Cell line, Subject
View Samples