Dynamic imbalance between cancer cell subpopulations induced by Transforming Growth Factor Beta (TGF-β) is associated with a DNA methylome switch [methylation]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE127828 | GEO | 2019/03/05
REPOSITORIES: GEO
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Project description:Distinct subpopulations of neoplastic cells within tumors, including hepatocellular carcinoma (HCC), display pronounced ability to initiate new tumors and induce metastasis. Recent evidence suggests that signals from transforming growth factor beta (TGF-β) may increase the survival of these so called tumor initiating cells leading to poor HCC prognosis. However, how TGF-β establishes and modifies the key features of these cell subpopulations is not fully understood. In the present report we describe the differential DNA methylome of CD133-negative and CD133-expressing liver cancer cells. Next, we show that TGF-β is able to increase the proportion of CD133+ cells in liver cancer cell lines in a way that is stable and persistent across cell division. This process is associated with stable genome-wide changes in DNA methylation that persist through cell division. Differential methylation in response to TGF-β is under-represented at promoter CpG islands and enriched at gene bodies, including a locus in the body of the de novo DNA methyl-transferase DNMT3B gene. Moreover, phenotypic changes induced by TGF-β, including the induction of CD133, are impaired by siRNA silencing of de novo DNA methyl-transferases. Our study reveals a self-perpetuating crosstalk between TGF-β signaling and the DNA methylation machinery, which can be relevant in the establishment of cellular phenotypes. This is the first indication of the ability of TGF-β to induce genome-wide changes in DNA methylation, resulting in a stable change in the proportion of liver cancer cell subpopulations.
2019-03-05 | GSE127763 | GEO
Project description:Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 39 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis. The cancer stem cell hypothesis posits that malignant growth arises from a rare population of progenitor cells within a tumor that provide it with unlimited regenerative capacity. Such cells also possess increased resistance to chemotherapeutic agents. Resurgence of chemoresistant disease following primary therapy typifies epithelial ovarian cancer and may be attributable to residual cancer stem cells, or cancer initiating cells, that survive initial treatment. As the cell surface marker CD133 identifies cancer initiating cells in a number of other malignancies, we sought to determine the potential role of CD133+ cells in epithelial ovarian cancer. We detected CD133 on ovarian cancer cell lines, in primary cancers, and on purified epithelial cells from ascitic fluid of ovarian cancer patients. We found CD133+ ovarian cancer cells generate both CD133+ and CD133- daughter cells, whereas CD133- cells divide symmetrically. CD133+ cells exhibit enhanced resistance to platinum-based therapy, drugs commonly used as first line agents for treatment of ovarian cancer. Sorted CD133+ ovarian cancer cells also form more aggressive tumor xenografts at a lower inoculum than their CD133- progeny. Epigenetic changes may be integral to the behavior of cancer progenitor cells and their progeny. In this regard, we found that CD133 transcription is controlled by both histone modifications and promoter methylation. Sorted CD133- ovarian cancer cells treated with DNA methyltransferase and histone deacetylase inhibitors show a synergistic increase in cell surface CD133 expression. Moreover, DNA methylation at the ovarian tissue active P2 promoter is inversely correlated with CD133 transcription. We also found that promoter methylation increases in CD133- progeny of CD133+ cells, with CD133+ cells retaining a less methylated or unmethylated state. Taken together, our results show that CD133 expression in ovarian cancer is directly regulated by epigenetic modifications and support the idea that CD133 demarcates an ovarian cancer initiating cell population. The activity of these cells may be epigenetically detected and such cells might serve as pertinent chemotherapeutic targets for reducing disease recurrence.
2010-11-17 | GSE25428 | GEO
Project description:Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 43 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis. The cancer stem cell hypothesis posits that malignant growth arises from a rare population of progenitor cells within a tumor that provide it with unlimited regenerative capacity. Such cells also possess increased resistance to chemotherapeutic agents. Resurgence of chemoresistant disease following primary therapy typifies epithelial ovarian cancer and may be attributable to residual cancer stem cells, or cancer initiating cells, that survive initial treatment. As the cell surface marker CD133 identifies cancer initiating cells in a number of other malignancies, we sought to determine the potential role of CD133+ cells in epithelial ovarian cancer. We detected CD133 on ovarian cancer cell lines, in primary cancers, and on purified epithelial cells from ascitic fluid of ovarian cancer patients. We found CD133+ ovarian cancer cells generate both CD133+ and CD133- daughter cells, whereas CD133- cells divide symmetrically. CD133+ cells exhibit enhanced resistance to platinum-based therapy, drugs commonly used as first line agents for treatment of ovarian cancer. Sorted CD133+ ovarian cancer cells also form more aggressive tumor xenografts at a lower inoculum than their CD133- progeny. Epigenetic changes may be integral to the behavior of cancer progenitor cells and their progeny. In this regard, we found that CD133 transcription is controlled by both histone modifications and promoter methylation. Sorted CD133- ovarian cancer cells treated with DNA methyltransferase and histone deacetylase inhibitors show a synergistic increase in cell surface CD133 expression. Moreover, DNA methylation at the ovarian tissue active P2 promoter is inversely correlated with CD133 transcription. We also found that promoter methylation increases in CD133- progeny of CD133+ cells, with CD133+ cells retaining a less methylated or unmethylated state. Taken together, our results show that CD133 expression in ovarian cancer is directly regulated by epigenetic modifications and support the idea that CD133 demarcates an ovarian cancer initiating cell population. The activity of these cells may be epigenetically detected and such cells might serve as pertinent chemotherapeutic targets for reducing disease recurrence. The objective of the study was to identify genes that are subject to DNA methylation through pharmacological inhibition of DNA methyltransferase activity in a panel of cancer cell lines. Cells were mock treated with culture media (mock treated) or treated with 5 µM decitabine for 72 hours. Resulting expression profiles were compared to identify genes with altered expression following decitabine treatment. These data represent two experiments: In the first, 43 established cell lines were mock treated or treated with decitabine to enable identification of genes differentially expressed as a result of inhibition of DNA methyltransferase activity. HEYA8-decitabine treated cells were run in replicate. In the second experiment, A2780 and PEO1 cells underwent flow activated cell sorting to separate CD133(+) from CD133(-) cells in each cell line; the sorted cell populations were cultured in the same manner as the first experiment and similarly mock treated or treated with decitabine. All specimens were arrayed in parallel and used for RMA normalization.
2010-11-17 | E-GEOD-25428 | biostudies-arrayexpress
Project description:Foxp3+ regulatory T cells (Treg cells) are essential for immune system homeostasis and suppression of excessive immune responses. Both TGF-β signaling and epigenetic modifications are important in the regulation of Foxp3 induction, but whether TGF-β signaling participates in the epigenetic regulation of Foxp3 has not been fully clarified. Here, we show that Uhrf1, which is induced by TCR stimulation and regulated by TGF-β signaling, controls Foxp3 methylation and iTreg cell differentiation. T cell-specific ablation of Uhrf1 led to Treg-biased differentiation in naïve T cells, with DNA hypomethylation upon TCR stimulation, and these Foxp3+ T cells had suppressive function. Uhrf1 maintained Foxp3 DNA methylation by recruiting Dnmt1 during cell division upon TCR stimulation. TGF-β treatment led to passive demethylation of the Foxp3 promoter to initiate its expression. Mechanistically, Uhrf1 was phosphorylated upon TGF-β stimulation and largely sequestered in the cytoplasm. Phosphorylated Uhrf1 underwent proteasomal degradation through inhibition of Usp7-mediated deubiquitination. Collectively, our study reveals a novel epigenetic mechanism of TGF-β-mediated iTreg cell differentiation regulated by Uhrf1 and reveals the differential role of active and passive demethylation in Foxp3 induction and stability.
2019-09-08 | GSE128480 | GEO
Project description:Methylthioadenosine phosphorylase (MTAP), a key enzyme in the adenine and methionine salvage pathways, catalyzes the hydrolysis of methylthioadenosine (MTA), a compound suggested to affect pivotal cellular processes in part through the regulation of protein methylation. MTAP is expressed in a wide range of cell types and tissues and its deletion is common to cancer cells and in liver injury. The aim of this study was to investigate the proteome and methyl proteome alterations triggered by MTAP deficiency in liver cells to define novel regulatory mechanisms that may explain the pathogenic processes of liver diseases. iTRAQ analysis resulted in the identification of 216 differential proteins (p<0.05) that suggest deregulation of cellular pathways as those mediated by ERK or NFκB. R-methyl proteome analysis lead to the identification of 74 differentially methylated proteins between SK-Hep1 and SK-Hep1+ cells, including 116 new methylation sites. Restoring normal MTA levels in SK-Hep1+ cells parallels the specific methylation of 56 proteins, including KRT8, TGF and CTF8A, which provides a novel regulatory mechanism of their activity with potential implications in carcinogenesis. Inhibition of RNA binding proteins methylation is especially relevant upon accumulation of MTA. As an example, methylation of quaking protein in R242 and R256 in SK-Hep1+ cells may play a pivotal role in the regulation of its activity as indicated by the up-regulation of its target protein p27 kip1. The phenotype associated with a MTAP deficiency was further verified in the liver of MTAP+/- mice. Our data support that MTAP deficiency leads to MTA accumulation and deregulation of central cellular pathways, increasing proliferation and decreasing the susceptibility to chemotherapeutic drugs, which involves differential protein methylation.
2016-02-01 | PXD002957 | Pride
Project description:Epigenetic modifications have emerged as central players in the coordination of gene expression networks during cardiac development. While several studies have investigated the role of histone modifications during heart development, relatively little is known about the role of DNA methylation. The purpose of the current study was to determine whether DNA methylation plays an important role in guiding transcriptional changes during the neonatal period, which is an important developmental window for cardiac maturation and cardiomyocyte cell cycle arrest. We used methyl binding domain protein sequencing (MBD-seq) and mRNA-seq to profile DNA methyation and gene expression respectively in neonatal hearts at P1 and P14 stages. Thousands of differentially methylated regions (DMRs) were identified between P1 and P14, the vast majority of which were hypermethylated. Gene ontology analysis revealed that these hypermethylated genes were associated with transcriptional regulation of important developmental signaling pathways, including Hedgehog, BMP, TGF beta, FGF and Wnt/b-catenin signaling. A significant enrichment for myogenic transcription factors and Smad2/3/4 binding sites was also noted among differentially methylated peaks at P14. This study provides novel evidence for widespread alterations in DNA methylation during post-natal heart maturation and suggests that DNA methylation plays an important role in cardiomyocyte cell cycle arrest during the neonatal period. We used methyl binding domain protein sequencing (MBD-seq) to profile DNA methyation in neonatal hearts at P1 and P14 stages (post-natal day 1 and 14 respectively) in three biological replicates.
2014-08-01 | E-GEOD-59969 | biostudies-arrayexpress
Project description:Dynamic imbalance between cancer cell subpopulations induced by Transforming Growth Factor Beta (TGF-β) is associated with a DNA methylome switch [methylation]
| PRJNA525600 | ENA
Project description:Background: To better understand the role DNA methylation plays in regulating gene expression in the developng heart and furthermore the role it plays in heart development we performed genome wide DNA methylation profiling of embryonic hearts at embryonic day (E)11.5 and E14.5 using methyl sensitive tiny fragment enrichment coupled with massive parallel sequencing by using the methyl-sensitive restriction enzyme HpyCH4IV, recognition site 'ACGT'. Results: We found that global methylation remains stable at analyzed 'ACGT' sites (1.64 million site) in developing hearts between E11.5 and E14.5. However, differential methylation was identified at individual loci enriched at genes involved in heart development suggesting a role for DNA methylation in the developing heart. Used Methyl Sensitive Tiny Fragment Enrichment/Massive Parallel Sequencing (MSFE/MPS) to assay methylation at 'ACGT' sites throughout the genome and generate a developmental profile of DNA methylation in the embryonic heart and to identify differences between developing mouse hearts at E11.5 and E14.5.
2014-06-27 | E-GEOD-55141 | biostudies-arrayexpress
Project description:Publication title: Distinct DNA methylation patterns characterize differentiated human embryonic stem cells and developing human fetal liver To investigate the role of DNA methylation during human development, we developed Methyl-seq, a method that assays DNA methylation at more than 90,000 regions throughout the genome. Performing Methyl-seq on human embryonic stem cells (hESCs), their derivatives and human tissues allowed us to identify several trends during hESC and in vivo liver differentiation. First, differentiation results in DNA methylation changes at a minimal number of assayed regions, both in vitro and in vivo (2-11%). Second, in vitro hESC differentiation is characterized by both de novo methylation and demethylation, whereas in vivo fetal liver development is characterized predominantly by demethylation. Third, hESC differentiation is uniquely characterized by methylation changes specifically at H3K27me3-occupied regions, bivalent domains and low-density CpG promoters (LCPs) suggesting that these regions are more likely to be involved in transcriptional regulation during hESC differentiation. Although both H3K27me3-occupied domains and LCPs are also regions of high variability in DNA methylation state during human liver development, these regions become highly unmethylated, which is a distinct trend from that observed in hESCs. Taken together, our results indicate that hESC differentiation has a unique DNA methylation signature that may not be indicative of in vivo differentiation. Keywords: Methyl-seq, hESC differentiation For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Illumina gene expression beadchips of human ES cell lines, ES-derived cells, and normal liver (15 samples).
2011-05-05 | E-GEOD-29070 | biostudies-arrayexpress
Project description:Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 43 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis. Seventeen primary cultures of ovarian cells (two pooled normal ovarian surface epithelium, two serous borderline tumors, one endometrioid and twelve serous epithelial ovarian cancers) were mock treated or treated with 5 µM 5-AzaC for 72 hours, followed by gene expression microarray analysis to enable identification of genes differentially expressed as a result of inhibition of DNA methyltransferase activity.
2010-11-17 | E-GEOD-25427 | biostudies-arrayexpress