Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis
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PROVIDER: PRJNA666637 | ENA |
REPOSITORIES: ENA
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Project description:Inhibition of CBP synergizes with the RNA-dependent mechanisms of azacitidine by limiting protein synthesis
| PRJNA666398 | ENA
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 | GSE158813 | GEO
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
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
Project description: Not available
| S-EPMC8523560 | biostudies-literature
Project description:Transcription activation involves RNA polymerase II (Pol II) recruitment and release from the promoter into productive elongation, but how specific chromatin regulators control these steps is not fully understood. Here we identify a novel activity of the co-regulator and histone acetyltransferase p300/CBP in positioning promoter-proximal paused Pol II. We find that CBP inhibition impedes transcription through the +1 nucleosome, causing âdribblingâ of Pol II from the canonical pause site genome-wide. We further discovered that promoters strongly occupied by Drosophila CBP and GAGA-factor have high levels of paused Pol II, a unique chromatin signature and strong expression regardless of cell type. Interestingly, CBP activity is rate-limiting for Pol II recruitment to these highly-paused promoters but for transit into elongation at other genes. Thus, we uncover a key role for CBP during transcription in directly controlling different rate-limiting steps depending on promoter features. Examination of transcriptional regulation with and without CBP inhibition for 10 minutes in Drosophila S2 cells. Two biological replicates for each condition.
2016-08-01 | E-GEOD-81649 | biostudies-arrayexpress
Project description:Transcription activation involves RNA polymerase II (Pol II) recruitment and release from the promoter into productive elongation, but how specific chromatin regulators control these steps is not fully understood. Here we identify a novel activity of the co-regulator and histone acetyltransferase p300/CBP in positioning promoter-proximal paused Pol II. We find that CBP inhibition impedes transcription through the +1 nucleosome, causing “dribbling” of Pol II from the canonical pause site genome-wide. We further discovered that promoters strongly occupied by Drosophila CBP and GAGA-factor have high levels of paused Pol II, a unique chromatin signature and strong expression regardless of cell type. Interestingly, CBP activity is rate-limiting for Pol II recruitment to these highly-paused promoters but for transit into elongation at other genes. Thus, we uncover a key role for CBP during transcription in directly controlling different rate-limiting steps depending on promoter features.
2016-08-01 | GSE81649 | GEO
Project description:Acute Myeloid Leukemias (AML) are severe hematomalignancies with dismal prognosis. The post-translational modification SUMOylation plays key roles in leukemogenesis and AML response to therapies. Here, we show that TAK-981 (subasumstat), a first-in-class SUMOylation inhibitor, is endowed with potent anti-leukemic activity in various preclinical models of AML. TAK-981 targets AML cell lines and patient blast cells in vitro and in vivo in xenografted mice with minimal toxicity on normal hematopoietic cells. Moreover, it synergizes with 5-azacitidine (AZA), a DNA-hypomethylating agent now used in combination with the BCL-2 inhibitor venetoclax to treat AML patients unfit for standard chemotherapies. Interestingly, TAK-981+AZA combination shows higher anti-leukemic activity than AZA+venetoclax combination both in vitro and in vivo, at least in the models tested. Mechanistically, TAK-981 potentiates the transcriptional reprogramming induced by AZA, promoting apoptosis, alteration of the cell cycle and differentiation of the leukemic cells. In addition, TAK-981+AZA treatment induces many genes linked to inflammation and immune response pathways. In particular, this leads to the secretion of type I interferon (IFN-I) by AML cells. Finally, TAK-981+AZA induces the expression of Natural Killer (NK)-activating ligands (MICA/B) and adhesion proteins (ICAM-1) at the surface of AML cells. Consistently, TAK-981+AZA-treated AML cells activate NKs and increase their cytotoxic activity. Targeting SUMOylation with TAK-981 may thus be a promising strategy to both sensitize AML cells to AZA and reduce their immune-escape capacities.
2023-08-29 | GSE212330 | GEO
Project description:SIRT6-CBP dependent Nuclear Tau Accumulation and its Role in Protein Synthesis.
| PRJNA719152 | ENA
Project description:Quantifying RNA Synthesis at Rate-Limiting Steps of Transcription Using Nascent RNA-sequencing Data
| PRJNA750851 | ENA