Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis

ABSTRACT: The nucleotide analogue azacitidine interferes with RNA and DNA metabolism and is currently the best treatment option for a subset of patients with high-risk myelodysplastic syndromes. However, only half of treated patients respond and almost all patients that initially respond eventually relapse. We performed an optimized loss-of-function shRNA screen in combination with azacitidine treatment in an MDS-derived acute myeloid leukemia cell line to identify chromatin regulators affecting drug response. We identified CBP, as a major regulator of azacitidine sensitivity. Compounds inhibiting the enzymatic activity of CBP synergistically reduced viability of MDS-derived AML cell lines when combined with AZA. Surprisingly, this effect was specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is limited to DNA incorporation. The identification of immediate target genes suggested that the effect of CBP inhibition is mediated by downregulation of genes encoding the translational machinery, which could be confirmed in proteomic analysis of nascent proteins. Furthermore, proteins most affected by CBP inhibition include key drivers of cell cycle progression.

ORGANISM(S): Homo sapiens

PROVIDER: GSE158813 | GEO | 2021/09/10

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein translation

Project description:The nucleotide analogue azacitidine (AZA) interferes with RNA and DNA metabolism and is currently the best treatment option for a subset of patients with high-risk myelodysplastic syndromes. However, only half of treated patients respond and almost all patients that initially respond eventually relapse. Thus, response-predicting biomarkers and new treatment options are urgently needed to improve the clinical management of these patients. Here, we performed a loss-of-function shRNA screen in combination with AZA treatment in a MDS-derived AML cell line to identify chromatin regulators affecting drug response. We identified the histone acetyl transferase and transcriptional co-activator CBP as a major regulator of AZA sensitivity. Compounds inhibiting the enzymatic activity of CBP synergistically reduced viability of MDS-derived AML cell lines when combined with AZA. Surprisingly, this affect was specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is limited to DNA incorporation. The identification of immediate target genes suggested that the effect of CBP inhibition is mediated by downregulation of genes encoding the translational machinery, which could be confirmed in proteomic analysis of nascent proteins. Furthermore, proteins most affected by CBP inhibition include key drivers of cycle progression. Taken together, our results identify a novel synergistic interaction between CBP inhibitors and specifically AZA that warrants further evaluation for the combinatorial treatment of high-risk MDS patients. Beyond the scope of MDS and AZA, we provide novel insight in the function of clinically promising CBP inhibitors that is related to unexpected interference with the translational machinery.

2021-09-22 | PXD021738 | Pride

Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis

Project description:The nucleotide analogue azacitidine interferes with RNA and DNA metabolism and is currently the best treatment option for a subset of patients with high-risk myelodysplastic syndromes. However, only half of treated patients respond and almost all patients that initially respond eventually relapse. We performed an optimized loss-of-function shRNA screen in combination with azacitidine treatment in an MDS-derived acute myeloid leukemia cell line to identify chromatin regulators affecting drug response. We identified CBP, as a major regulator of azacitidine sensitivity. Compounds inhibiting the enzymatic activity of CBP synergistically reduced viability of MDS-derived AML cell lines when combined with AZA. Surprisingly, this effect was specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is limited to DNA incorporation. The identification of immediate target genes suggested that the effect of CBP inhibition is mediated by downregulation of genes encoding the translational machinery, which could be confirmed in proteomic analysis of nascent proteins. Furthermore, proteins most affected by CBP inhibition include key drivers of cell cycle progression.

2021-09-10 | GSE158738 | GEO

Different gene sets are associated with azacitidine response in vitro and myelodysplastic syndrome patients

Project description:Myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic disorders and characterized by dysplasia, ineffective hematopoiesis and predisposition to secondary acute myeloid leukemia (sAML). Azacitidine (AZA) is the standard care for high-risk MDS patients not eligible for allogenic bone marrow transplantation. However, only half of the patients respond and all patients eventually relapse. Response predicting biomarkers and combinatorial drugs targets enhancing response and its duration are needed. Here, we have taken a dual approach. First, we have evaluated genes encoding chromatin regulators for their capacity to modulate AZA response. We were able to validate several genes, whose genetic inhibition affected the cellular AZA response, including four genes encoding components of ISWI chromatin remodelling complex pointing towards a specific function and co-vulnerability. Second, we have used a classical cohort analysis approach measuring the association of expression of a gene panel in bone marrow samples collected at diagnosis of 36 MDS patients. The gene panel included the identified AZA modulators, genes known to be involved in AZA metabolism and previously identified candidate modulators. In addition to confirming a number of previously made observations, we were able to identify several new associations, such as SMARCA5 as positive indicator for AZA response, or NSUN3 that correlated with increased overall survival. Taken together we have identified a number of genes associated with AZA response in vitro and in patients. These groups of genes are largely non-overlapping suggesting that different gene sets need to be exploited for the development of combinatorial drug targets and response-predicting biomarkers.

2022-11-02 | GSE208736 | GEO

Identification of genes that may predict response to azacitidine treatment.

Project description:Azacitidine (AZA) is a hypomethylating drug used to treat disorders associated with myelodysplasia and related neoplasms. Approximately 50% of patients do not respond to AZA and have very poor outcomes. It is of great interest to identify predictive biomarkers for AZA responsiveness. Therefore, we searched for specific genes whose expression level was associated with response status.Using microarrays, we analyzed gene expression patterns in bone marrow CD34+ cells from 32 patients with myelodysplastic syndromes, chronic myelomonocytic leukemia, and acute myeloid leukemia with myelodysplasia-related changes before AZA therapy. Total RNA was isolated from bone marrow CD34+ cells obtained from myelodysplasia and related neoplasms patients who underwent treatment with 5-azacytidine (AZA, Vidaza). Using Illumina Human HT-12 v. 4 microarrays, we assayed gene expression profiles in patient CD34+ cells before AZA treatment in order to collect basic data for search for markers of the prediction of therapy response.

2016-02-10 | E-GEOD-77750 | biostudies-arrayexpress

Identification of genes that may predict response to azacitidine treatment.

2016-02-10 | GSE77750 | GEO

Azacitidine Modulates the Mesenchymal Stromal Cell Compartment in Myelodysplastic Syndromes

Project description:Mesenchymal stromal cells (MSC) are crucial components of the bone marrow (BM) microenvironment essential for regulating self-renewal, survival and differentiation of hematopoietic stem/progenitor cells (HSPC) in the stem cell niche. MSC are functionally and phenotypically altered in myelodysplastic syndromes (MDS), contributing to disease progression. MDS MSC do not harbor recurrent genetic alterations but have been shown to exhibit an altered methylome compared to MSC from healthy controls. We examined growth, differentiation and HSPC-supporting capacity of ex vivo expanded MSC from MDS patients in comparison to age-matched healthy controls after direct treatment in vitro with the hypomethylating agent azacitidine (AZA). We show that AZA exerts a direct effect on MSC by modulating their differentiation potential. Osteogenesis was significantly boosted in healthy MSC while adipogenesis was inhibited in both healthy and MDS MSC. In co-culture experiments, both AZA treated MDS MSC and healthy MSC exhibited enhanced support of non-clonal HSPC which was associated with increased cell cycle induction. Conversely, clonal MDS HSPC were inhibited by contact with AZA treated MSC. RNA-sequencing analyses of stromal cells revealed changes in pathways essential for HSPC support as well as in immune regulatory pathways. In sum, our data demonstrate that AZA treatment of stromal cells leads to upregulation of HSPC-supportive genes and cell cycle induction in co-cultured healthy HSPC, resulting in a proliferative advantage over clonal HSPC. Thus, restoration of functional hematopoiesis by AZA may be driven by activated stromal support factors in MSC providing cell cycle cues to healthy HSPC.

2018-12-19 | GSE112461 | GEO

Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis

Project description:Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis

| PRJNA666398 | ENA

Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis

Project description:Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis

| PRJNA666637 | ENA

Azacitidine treated AML cells reveals highly variable cell surface proteome remodeling [Affymetrix]

Project description:Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are diseases of abnormal hematopoietic differentiation with aberrant epigenetic alterations. Azacitidine (AZA) is a DNA methyltransferase inhibitor (DNMTi) widely used to treat MDS and AML, yet the impact of AZA on the cell surface proteome has not been defined. To identify potential therapeutic targets for use in combination with AZA in AML patients, we investigated the effects of AZA treatment on four AML cell lines representing different stages of differentiation. The effect of AZA treatment on these cell lines was characterized at three levels: the DNA methylome, the transcriptome, and the cell surface proteome. Untreated AML cell lines showed substantial overlap at all three omics level; however, while AZA treatment globally reduced DNA methylation in all cell lines, changes in the transcriptome and surface proteome were subtle and differed among the cell lines. Transcriptome analysis identified five commonly upregulated coding genes upon AZA treatment in all four cell lines, TRPM4 being the only gene encoding a surface protein, and surface proteomics analysis found no commonly regulated proteins. Gene Set Enrichment Analysis (GSEA) of differentially-regulated RNA and surface proteins showed a decrease in metabolism pathways and an increase in immune defense response pathways. As such, AZA treatmentled to diverse effects at the individual gene and protein level but converged to common responses at the pathway level. Given the heterogeneous responses in the four cell lines, the potential therapeutic strategies for AML in combinations with AZA are discussed.

2018-12-01 | GSE123207 | GEO