The organization of mammalian DNA replication is poorly understood. We have produced genome-wide high-resolution dynamic maps of the timing of replication in human erythroid, mesenchymal and embryonic stem cells using TimEX, a method that relies on gaussian convolution of massive, highly redundant determinations of DNA copy number variations during S phase obtained using either high-density oligonucleotide tiling arrays or massively-parallel sequencing to produce replication timing profiles. We show that in untransformed human cells, timing of replication is highly regulated and highly synchronous, and that many genomic segments are replicated in temporal transition regions devoid of initiation where replication forks progress unidirectionally from origins that can be hundreds of kilobases away. Absence of initiation in one transition region is shown at the molecular level by SMARD analysis. Comparison of ES and erythroid cells replication patterns revealed that these cells replicate about 20% of their genome in different quarter of S phase and that ES cells replicate a larger proportion of their genome in early S phase than erythroid cells. Importantly, we detected a strong inverse relationship between timing of replication and distance to the closest expressed gene. This relationship can be used to predict tissue specific timing of replication profiles from expression data and genomic annotations. We also provide evidence that early origins of replication are preferentially located near highly expressed genes, that mid firing origins are located near moderately expressed genes and that late firing origins are located far from genes.
Predictable dynamic program of timing of DNA replication in human cells.
Specimen part
View SamplesOvarian cancer is a deadly gynecological malignancy for which novel biomarkers and therapeutic targets are imperative for improving survival. To investigate the role of histone H1 in ovarian cancer cells, we overexpress a histone H1 variant, H1.3, in the OVCAR-3 epithelial ovarian cancer cell line. RNA was extracted from OV-3/H1.3(H) cells (OVCAR-3 with overexpression of H1.3) and control cells of OVCAR-3 transfected with vectors without H1.3. The microarray chip used was human Affymetrix ST1.0 array. Gene expression changes caused by overexpression of H1.3 in OVCAR-3 cells were identified.
Histone h1.3 suppresses h19 noncoding RNA expression and cell growth of ovarian cancer cells.
Specimen part, Cell line
View SamplesWe show that NRF2 activation drives hepatocellular carcinoma development in vivo. Moreover, NRF2 undergoes glucose dependent modification called glycation and requires the de-glycating enzyme FN3K to maintain NRF2' oncogenic functions. Overall design: Gene expression analysis in MYC-driven murine HCC with and without NRF2 activation. NRF2 is activated by targeting its negative regulators Keap1 or Cul3 or targeting NRF2 ETGE motif by sgRNA/Cas9 editing.
The Oncogenic Action of NRF2 Depends on De-glycation by Fructosamine-3-Kinase.
Specimen part, Disease, Disease stage, Subject
View SamplesWe apply the cellular reprogramming experimental paradigm to two disorders caused by symmetrical copy number variations (CNV) of 7q11.23 and displaying a striking combination of shared as well as symmetrically opposite phenotypes: Williams Beuren syndrome (WBS) and 7q microduplication syndrome (7dupASD). Through a uniquely large and informative cohort of transgene-free patient-derived induced pluripotent stem cells (iPSC), along with their differentiated derivatives, we find that 7q11.23 CNV disrupt transcriptional circuits in disease-relevant pathways already at the pluripotent state. These alterations are then selectively amplified upon differentiation into disease-relevant lineages, thereby establishing the value of large iPSC cohorts in the elucidation of disease-relevant developmental pathways. In addition, we functionally define the quota of transcriptional dysregulation specifically caused by dosage imbalances in GTF2I (also known as TFII-I), a transcription factor in 7q11.23 thought to play a critical role in the two conditions, which we found associated to key repressive chromatin modifiers. Finally, we created an open-access web-based platform (accessible at http://bio.ieo.eu/wbs/ ) to make accessible our multi-layered datasets and integrate contributions by the entire community working on the molecular dissection of the 7q11.23 syndromes. Overall design: We reprogrammed skin fibroblasts from patients harbouring a 7q11.23 hemi-deletion (WBS, 4 patients; +1 atypical deletion, AtWBS) or microduplication (7dupASD; 2 patients), as well as from one unaffected relative and two unrelated controls, using integration-free mRNA-reprogramming, leading to the establishment of a total of 27 characterized iPSC clones. We profiled these by RNAseq (either polyA or ribo-zero). To isolate the contribution of GTF2I to the transcriptional dysregulation, we created stable lines expressing a short hairpin against GTF2I from a representative subset of these iPSC clones, and profiled by RNAseq 7 such lines along with their respective scramble controls. Finally, we also profiled by RNAseq mesenchymal stem cells (MSC) derived from a representative subset of the lines.
RNAontheBENCH: computational and empirical resources for benchmarking RNAseq quantification and differential expression methods.
No sample metadata fields
View SamplesMalignant gliomas constitute one of the most significant areas of unmet medical need, due to the invariable failure of surgical eradication and their marked molecular heterogeneity. Accumulating evidence has revealed a critical contribution by the Polycomb axis of epigenetic repression. However, a coherent understanding of the regulatory networks affected by Polycomb during gliomagenesis is still lacking. Here we integrate transcriptomic and epigenomic analyses to define Polycomb-dependent networks that promote gliomagenesis, validating them both in two independent mouse models and in a large cohort of human samples. We found that Polycomb dysregulation in gliomagenesis affects transcriptional networks associated to invasiveness and de-differentiation. The dissection of these networks uncovers Zfp423 as a crtitical Polycomb-dependent transcription factor whose silencing negatively impacts survival. The anti-gliomagenic activity of Zfp423 requires interaction with the SMAD proteins within the BMP signaling pathway, pointing to a novel synergic circuit through which Polycomb inhibits BMP signaling. Overall design: Transcriptomic analysis of two different stages of gliomagenesis
Polycomb dysregulation in gliomagenesis targets a Zfp423-dependent differentiation network.
Specimen part, Cell line, Subject
View SamplesAnalysis of epigenetic changes of pericytes after ischemia-reperfusion renal injury. The hypothesis tested in the present study was that epigenetic change develope in pericytes after acute kidney injury. This phenotype change would cause pericyte to be more proliferative and profibrotic. Results provide important information of the epigenetic change of pericytes, such as specific mechano-responsive genes, up-regulated specific proliferative and profibrotic functions.
Methylation in pericytes after acute injury promotes chronic kidney disease.
Specimen part
View SamplesmiRNA high-throughput sequencing was used to investigate endometriosis lesion-specific miRNA expression profiles by comparing a set of paired samples of peritoneal endometriotic lesions and matched healthy surrounding tissue together with eutopic endometrium of the same patients. We found that miRNAs of surrounding peritoneal tissue mask most of the miRNA expression differences that could originate from endometriotic tissue and thus only miRNAs with significantly different levels in the endometriotic lesions compared to peritoneal tissue were detected. According to the results of this study, two miRNAs – miR-34c and miR-449a showed remarkably higher expression in lesions compared to healthy tissue. Overall design: Eleven tissue samples (two endometria, five peritoneal lesions and four matched adjacent normal-appearing tissues) were analysed from two patients with a histologically confirmed diagnosis of moderate-severe endometriosis (III-IV stage)
High-throughput sequencing approach uncovers the miRNome of peritoneal endometriotic lesions and adjacent healthy tissues.
No sample metadata fields
View SamplesTranscription factor (TF)-induced reprogramming of somatic cells into induced pluripotent stem cells (iPSC) is associated with genome-wide changes in chromatin modifications. Polycomb-mediated histone H3 lysine-27 trimethylation (H3K27me3) has been proposed as a defining mark that distinguishes the somatic from the iPSC epigenome. Here, we dissected the functional role of H3K27me3 in TF-induced reprogramming through the inactivation of the H3K27 methylase EZH2 at the onset of reprogramming. Our results demonstrate that surprisingly the establishment of functional iPSC proceeds despite global loss of H3K27me3. iPSC lacking EZH2 efficiently silenced the somatic transcriptome and differentiated into tissues derived from the three germ layers. Remarkably, the genome-wide analysis of H3K27me3 in Ezh2 mutant iPSC cells revealed the retention of this mark on a highly selected group of Polycomb targets enriched for developmental regulators controlling the expression of lineage specific genes. Erasure of H3K27me3 from these targets led to a striking impairment in TF-induced reprogramming. These results indicate that PRC2-mediated H3K27 trimethylation is required on a highly selective core of Polycomb targets whose repression enables TF-dependent cell reprogramming.
Cell reprogramming requires silencing of a core subset of polycomb targets.
Specimen part
View SamplesCell-type specific RNA-seq is a powerful approach for unravelling molecular processes of endometrial receptivity, and to detect novel sensitive biomarkers of receptivity. Overall design: 16 paired endometrial tissue samples from pre-receptive (defined as LH2) and receptive phase endometria (defined as LH8) from Estonia (defined as E) and Spain (defined as S) were collected. CD9-positive epithelial cells (defined as epithelium) and CD13-positive stromal cells (defined as stroma) were isolated with fluorescent activated cell sorting (FACS) and full transcriptome analysis was performed by RNA-seq.
Meta-signature of human endometrial receptivity: a meta-analysis and validation study of transcriptomic biomarkers.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Research resource: progesterone receptor targetome underlying mammary gland branching morphogenesis.
Sex, Age, Specimen part, Treatment
View Samples