Expression profiling of DNMT1 inhibitors in HCT116 cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE30985 | GEO | 2011/12/01
SECONDARY ACCESSION(S): PRJNA146197
REPOSITORIES: GEO
Similar Datasets
Project description:Epigenetic changes accompany tumorigenesis and are required for tumor maintenance. Modulation of DNA methylation state, histone acetylation, and histone methylation, as well as reversal of disease-associated epigenetic state aberrations, can be disruptive to malignant disease progression. We produced lipophilic prodrugs of decitabine, which is a DNA methyltransferase inhibitor and is efficacious in treatment of myelodysplastic syndromes when dosed subcutaneously. Comparison of parent and prodrug activities in vitro and in vivo revealed comparable effects and unveiled several novel features of nucleoside analog molecular activity in vitro. HCT116 were treated for 72 hour with Decitabine, Azacytidine and various prodrugs in duplicates at different dose concentrations. Cells were also treated with DMSO as control (quadrpulets), RNA was extracted and samples were hybridized to Affymetrix Hu133plus 2.0 arrays.
2011-12-01 | E-GEOD-30985 | biostudies-arrayexpress
Project description:The FDA-approved DNA hypomethylating agents (DHAs) like 5-azacytidine (5AC) and decitabine (DAC) demonstrate efficacy in the treatment of hematologic malignancies. Despite previous reports that showed histone acetylation changes upon using these agents, the exact mechanism underpinning these changes is unknown. In this study, we investigated the relative potency of the nucleoside analogs and non-nucleoside analogs DHAs on DNA methylation reversal using DNA pyrosequencing. Additionally, we screened their effect on the enzymatic activity of the histone deacetylase sirtuin family (SIRT1, SIRT2, SIRT3, SIRT5 and SIRT6) using both recombinant enzymes and nuclear lysates from leukemia cells. The nucleoside analogs (DAC, 5AC and zebularine) were the most potent DHAs and increased the enzymatic activity of SIRT6 without showing any significant increase in other sirtuin isoforms. ChIP-Seq analysis of bone marrow cells derived from six acute myeloid leukemia (AML) patients and treated with the nucleoside analog DAC induced genome-wide acetylation changes in H3K9, the physiological substrate for SIRT6. Data pooling from the six patients showed significant acetylation changes in 187 gene loci at different chromosomal regions including promoters, coding exons, introns and distal intergenic regions. Signaling pathway analysis showed that H3K9 acetylation changes are linked to AML-relevant signaling pathways like EGF/EGFR and Wnt/Hedgehog/Notch. To our knowledge, this is the first report to identify the nucleoside analogs DHAs as activators of SIRT6. Our findings provide a rationale against the combination of the nucleoside analogs DHAs with SIRT6 inhibitors or chemotherapeutic agents in AML due to the role of SIRT6 in maintaining genome integrity and DNA repair.
2020-07-28 | GSE152804 | GEO
Project description:Masitinib, a highly selective protein kinase inhibitor, can sensitise gemcitabine-refractory cancer cell lines when used in combination with gemcitabine. A reverse proteomic approach has identified the target responsible for this sensitisation: the deoxycytidine kinase (dCK). Masitinib, as well as other protein kinase inhibitors such as imatinib, interact with dCK and provoke an unforeseen conformational-dependent activation of this nucleoside kinase, modulating phosphorylation of nucleoside analogue drugs. This phenomenon leads to an increase of prodrug phosphorylation of most of the chemotherapeutic drugs activated by this nucleoside kinase. The unforeseen dual activity of protein kinase inhibition/nucleoside kinase activation could be of great therapeutic benefit, through either reducing toxicity of therapeutic agents by maintaining effectiveness at lower doses or by counteracting drug resistance initiated via down modulation of dCK target.
2017-11-13 | PXD007765 | Pride
Project description:Stable inheritance of DNA methylation is critical for maintaining the differentiated phenotypes in multicellular organisms. However, the molecular basis ensuring high fidelity of maintenance DNA methylation is largely unknown. Here, we demonstrate that two distinct modes of DNMT1 recruitment, one is DNA replication-coupled and the other is uncoupled mechanism, regulate the stable inheritance of DNA methylation. PCNA-associated factor 15 (PAF15) represents a primary target of UHRF1 and undergoes dual mono-ubiquitylation (PAF15Ub2) on chromatin. PAF15Ub2 specifically interacts with DNMT1 and controls the recruitment of DNMT1 in a DNA replication-coupled manner. Thus, loss of PAF15Ub2 results in impaired DNA methylation at sites replicating during early S phase. In contrast, outside of S phase or when PAF15 ubiquitylation is perturbed, UHRF1 ubiquitylates histone H3 to promote DNMT1 recruitment. Together, we identify replication-coupled and uncoupled mechanisms of maintenance DNA methylation, both of which collaboratively ensure the stable DNA methylation.
2020-02-25 | PXD015282 | Pride
Project description:DNA methylation and the Polycomb Repression System are epigenetic mechanisms that play important roles in maintaining transcriptional repression. Recent evidence suggests that DNA methylation can attenuate the binding of Polycomb protein components to chromatin and thus plays a role in determining their genomic targeting. However, whether this role of DNA methylation is important in the context of transcriptional regulation is unclear. By genome-wide mapping of the Polycomb Repressive Complex 2 (PRC2)-signature histone mark, H3K27me3, in severely DNA hypomethylated mouse somatic cells, we show that hypomethylation leads to widespread H3K27me3 redistribution, in a manner that reflects the local DNA methylation status in wild-type cells. Unexpectedly, we observe striking loss of H3K27me3 and PRC2 from Polycomb-target gene promoters in DNA hypomethylated cells, including Hox gene clusters. Importantly, we show that many of these genes become ectopically expressed in DNA hypomethylated cells, consistent with loss of Polycomb-mediated repression. An intact DNA methylome is required for appropriate Polycomb-mediated gene repression by constraining PRC2 targeting. These observations identify a previously unappreciated role for DNA methylation in gene regulation and therefore influence our understanding of how this epigenetic mechanism contributes to normal development and disease. Three replicates of each sample are compared
2013-02-12 | E-GEOD-44277 | biostudies-arrayexpress
Project description:Heterochromatin-specific histone modifications frequently coexist with mammalian DNA methylation to orchestrate a repressive chromatin state. However, it remains elusive how these epigenetic modifications crosstalk. Here, we report that the first bromoadjacent homology (BAH1) domain and the replication foci targeting sequence (RFTS) of maintenance DNA methyltransferase DNMT1 function as readers for H4K20me3 and H3K9me3, respectively. Engagements of H4K20me3 by BAH1 and H3K9me3 by RFTS ensure localization of DNMT1 to heterochromatin in cells, and cooperate with the RFTS-ubiquitination readout to allosterically stimulate DNMT1 s methylation activity at both global and focal levels. Strikingly, there is intramolecular crosstalk between the RFTS and BAH1 domains, which profoundly impacts the maintenance of DNA methylation and genomic resistance to radiation damage. Together, our study reveals an all-in-one model for DNMT1 in which repressive histone modifications directly influence the cellular landscape of DNA methylation and genomic stability, a process implicative of the DNMT1-related pathogenesis.
2020-07-27 | GSE145698 | GEO
Project description:DNA methylation and the Polycomb Repression System are epigenetic mechanisms that play important roles in maintaining transcriptional repression. Recent evidence suggests that DNA methylation can attenuate the binding of Polycomb protein components to chromatin and thus plays a role in determining their genomic targeting. However, whether this role of DNA methylation is important in the context of transcriptional regulation is unclear. By genome-wide mapping of the Polycomb Repressive Complex 2 (PRC2)-signature histone mark, H3K27me3, in severely DNA hypomethylated mouse somatic cells, we show that hypomethylation leads to widespread H3K27me3 redistribution, in a manner that reflects the local DNA methylation status in wild-type cells. Unexpectedly, we observe striking loss of H3K27me3 and PRC2 from Polycomb-target gene promoters in DNA hypomethylated cells, including Hox gene clusters. Importantly, we show that many of these genes become ectopically expressed in DNA hypomethylated cells, consistent with loss of Polycomb-mediated repression. An intact DNA methylome is required for appropriate Polycomb-mediated gene repression by constraining PRC2 targeting. These observations identify a previously unappreciated role for DNA methylation in gene regulation and therefore influence our understanding of how this epigenetic mechanism contributes to normal development and disease.
2013-02-12 | GSE44277 | GEO
Project description:DNA methyltransferase inhibitors have improved the prognosis of myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML). However, these agents must be administered intravenously or subcutaneously because they are degraded easily by cytidine deaminase (CDA). OR2100 (OR21), an oligonucleotide comprising decitabine nucleoside 5'-O-trisilylate, resists degradation by CDA. Direct duodenal administration led to high plasma concentrations of OR21 in a cynomolgus monkey model. Transcriptome and methylome analysis of MDS and AML cell lines revealed that OR21 enriched expression of genes associated with tumour suppression, cell differentiation, and immune system processes via alteration of regional promoter methylation. Conversely, immune system process pathways were downregulated in azacytidine-resistant AML cells, indicating that these pathways play a pivotal role in the action of hypomethylating agents. Both in vivo and in vitro, OR21 showed anti-leukaemia effects against MDS and AML cells (including AZA-resistant), and a better safety profile than decitabine. These results suggest that OR21 is a candidate drug for a phase 1 study as an alternative to DAC.
2020-04-09 | GSE148314 | GEO
Project description:We found previously that the effect of decitabine (DAC) on hematopoietic stem cell viability differed between Mll5 wildtype and null cells. We therefore investigated the role of MLL5 expression levels on outcome of AML patients who were treated with decitabine. High MLL5 expressing AML patients have improved overall survival when treated with decitabine. In transformed murine cells, loss of Mll5 was associated with resistance to low-dose decitabine, less frequent promoter methylation, and reduced demethylation upon decitabine treatment. These data suggest a biological link between MLL5 expression and decitabine response involving regulation of DNA methylation. Leukemia cell model was generated by co-transfer of HOXA9 and MEIS1 into Mll5 wildtype or knockout mouse bone marrow cells. MeDIP was performed in Mll5+/+ HOXA9/MEIS1 and Mll5-/- HOXA9/MEIS1 leukemic cells, untreated or treated with 3-day exposure of 20 nM decitabine, triplicate for each condition. MeDIP-enriched DNA was amplified with the GenomePlex Complete Whole Genome Amplification (WGA) Kit (Sigma-Aldrich). DNA from three MeDIP and WGA of each cell type and treatment was pooled for subsequent microarray analysis. The enriched DNA and corresponding input genomic DNA was labeled, hybridized and scanned on Agilent custom mouse promoter microarrays (Agilent-025976 AP_1M_Custom_CH3, assembly build mm9). The methylation value of individual probes was defined by the signal intensity ratio of MeDIP DNA (Cy3) compared to input DNA (Cy5) . Methylated DNA immunoprecipitation coupled with Agilent mouse promoter CpG arrays (MeDIP-chip)
2014-07-01 | E-GEOD-52199 | biostudies-arrayexpress
Project description:Progenitor cells maintain self-renewing tissues throughout life by sustaining their capacity for proliferation while suppressing cell cycle exit and terminal differentiation. DNA methylation provides a potential epigenetic mechanism for the cellular memory needed to preserve the somatic progenitor state through repeated cell divisions. DNA methyltransferase 1 (DNMT1) maintains DNA methylation patterns after cellular replication. Although dispensable for embryonic stem cell maintenance, a clear role for DNMT1 in maintaining the progenitor state in constantly replenished somatic tissues, such as mammalian epidermis, is uncharacterized. Here we show that DNMT1 is essential for supporting epidermal progenitor cell function. DNMT1 protein was found enriched in undifferentiated cells, where it was required to retain proliferative stamina and suppress differentiation. In tissue, DNMT1 depletion led to exit from the progenitor cell compartment, premature differentiation and eventual tissue loss. These effects correlated with DNA methylation as genome-wide analysis revealed that a significant portion of epidermal differentiation gene promoters were methylated in self-renewing conditions but were subsequently demethylated during differentiation. Gene expression analysis: To establish a differentiation signature for primary human keratinocytes, total RNA was isolated in biologic duplicate from cells cultured in growth conditions and high calcium differentiation conditions and hybridized to Affymetrix HG-U133 2.0 Plus arrays. This gene signature was also compared to DNMT1 deficient cells cultured in growth conditions. Methylated DNA profiling: To globally characterize DNA methylation in primary human keratinocytes, genomic DNA was immunoprecipitated using a 5-methylcytidine antibody, amplified, and hybridized to NimbleGen HG18 promoter tiling arrays. Profiling was done using DNA isolated in growth conditions as well as differentiation conditions.
2010-06-23 | E-GEOD-18590 | biostudies-arrayexpress