Differential pre-mRNA processing in Crebbp+/- mice
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE27987 | GEO | 2011/08/25
SECONDARY ACCESSION(S): PRJNA137727
REPOSITORIES: GEO
Similar Datasets
Project description:The presence of unspliced transcripts in hematopoietic stem cells (HSCs) and the proposed association of CREBBP with the constitutive production of unspliced RNA and with pre-mRNA processing prompted us to examine more closely an anomaly we had noted in microarray-based gene expression studies but had previously attributed to experimental noise. We noticed that more than half of the probe sets down-regulated in Crebbp+/- fetal liver HSCs (FLHSCs) relative to wild-type (WT) mapped entirely within introns, rather than detecting exonic or spliced sequences. We therefore set out to test whether this might be evidence that reduced CREBBP levels selectively alter the generation of full-length, unspliced pre-mRNA. We also asked whether this process might be associated with differentiation since self-renewal and lineage commitment are the both responses for which HSCs are primed. Total RNA from wild-type, Crebbp+/-, Ep300+/-, Cdkn1a-/- FLHSCs and from wild type and Crebbp+/- mouse embryonic fibroblasts (MEFs) was isolated and hybridized to Affymetrix Mouse 430 2.0 expression microarrays. Fetal liver HSC RNA was amplified using the Ovation kit prior to hybridization. cell type comparison
2011-08-24 | E-GEOD-27987 | biostudies-arrayexpress
Project description:Myelodysplastic syndrome (MDS) is considered a disease of hematopoietic stem cell (HSC) origin. To begin to unravel the molecular mechanisms underlying the deregulation of HSCs in MDS, we performed comparative gene expression profiling on Crebbp+/- and wild type HSCs. We chose to isolate HSCs from the fetal liver (FLHSC) because at this stage there were no differences in cell number between Crebbp+/- and wild type fetal livers, suggesting no overt hematopoietic differences. Thus, any change in gene expression found in Crebbp+/- FLHSCs is likely to reflect the initially compromised genetic program of HSC regulation, as opposed to that of Crebbp+/- HSCs in adult bone marrow, where secondary changes in gene expression may also occur as compensatory mechanisms for a compromised or failing hematopoietic system. We used day 14.5 post coitus FLHSC (Sca-1+,Lin-,AA4.1+,c-Kit++) from wild type (wt) and Crebbp heterozygous (ht) embryos to examine changes in gene expression before overt myelodysplastic disease manifestation. Total RNA from wt and Crebbp+/- FLHSCs was isolated, PCR-amplified using the Ovation RNA amplification system and hybridized to Affymetrix Mouse 430 2.0 expression microarrays.
2012-01-01 | E-GEOD-18061 | biostudies-arrayexpress
Project description:We found that the bone marrow microenvironment of Crebbp+/- mice was unable to properly maintain the immature stem - and progenitor pools. Instead, it stimulates myeloid differentiation that progresses into a myeloproliferative-like disease. Since CREBBP is a transcriptional co-activator, we used gene expression analysis to globally assess functional deficiencies in Crebbp+/- bone marrow stroma cells at a molecular level. Ep300 encodes a protein which is highly similar in structure and function to CREBBP; nevertheless, Ep300+/- mice suffer neither excessive myeloid differentiation nor loss of HSCs. Therefore, to identify expression changes specifically related to Crebbp heterozygosity, we focused on genes that showed significant differences in expression levels between Crebbp+/- and wild-type bone marrow stroma but no difference between Ep300+/- and wild-type. Bone marrow stroma was established from wild-type, Crebbp+/- and Ep300+/- mice that were 3-4 months old for RNA extraction and hybridization on Affymetrix microarrays. There are 4 biological replicates for each genotype used.
2011-03-01 | E-GEOD-24773 | biostudies-arrayexpress
Project description:Myelodysplastic syndrome (MDS) is considered a disease of hematopoietic stem cell (HSC) origin. To begin to unravel the molecular mechanisms underlying the deregulation of HSCs in MDS, we performed comparative gene expression profiling on Crebbp+/- and wild type HSCs. We chose to isolate HSCs from the fetal liver (FLHSC) because at this stage there were no differences in cell number between Crebbp+/- and wild type fetal livers, suggesting no overt hematopoietic differences. Thus, any change in gene expression found in Crebbp+/- FLHSCs is likely to reflect the initially compromised genetic program of HSC regulation, as opposed to that of Crebbp+/- HSCs in adult bone marrow, where secondary changes in gene expression may also occur as compensatory mechanisms for a compromised or failing hematopoietic system. We used day 14.5 post coitus FLHSC (Sca-1+,Lin-,AA4.1+,c-Kit++) from wild type (wt) and Crebbp heterozygous (ht) embryos to examine changes in gene expression before overt myelodysplastic disease manifestation.
2012-01-01 | GSE18061 | GEO
Project description:We found that the bone marrow microenvironment of Crebbp+/- mice was unable to properly maintain the immature stem - and progenitor pools. Instead, it stimulates myeloid differentiation that progresses into a myeloproliferative-like disease. Since CREBBP is a transcriptional co-activator, we used gene expression analysis to globally assess functional deficiencies in Crebbp+/- bone marrow stroma cells at a molecular level. Ep300 encodes a protein which is highly similar in structure and function to CREBBP; nevertheless, Ep300+/- mice suffer neither excessive myeloid differentiation nor loss of HSCs. Therefore, to identify expression changes specifically related to Crebbp heterozygosity, we focused on genes that showed significant differences in expression levels between Crebbp+/- and wild-type bone marrow stroma but no difference between Ep300+/- and wild-type.
2011-03-01 | GSE24773 | GEO
Project description:The contribution of the majority of frequently mutated genes to tumourigenesis is not fully defined. Many aggressive human cancers, such as triple negative breast cancers (TNBCs), have a poor prognosis and lack tractable biomarkers and targeted therapeutic options. Here, we systematically characterize loss-of-function mutations to generate a functional map of novel driver genes in a 3-dimensional model of breast cancer heterogeneity that more readily recapitulates the unfavourable tumour microenvironment in vivo. This identified the histone acetyltransferase CREBBP as a potent tumour suppressor gene whose silencing provided a 3D-specific growth advantage only under oxygen and nutrient deplete conditions. CREBBP protein expression was altered in a substantial proportion of TNBCs as well as several other solid tumours, including endometrial, bladder, ovarian and squamous lung cancers. In multiple primary tumours and cell models, loss of CREBBP activity resulted in upregulation of the FOXM1 transcriptional network. Strikingly, treatment with a range of CDK4/6 inhibitors (CDK4/6i), that indirectly target FOXM1 activity, selectively impaired growth in both CREBBP-altered spheroids and cell line xenografts and patient derived models from multiple tumour types. This study is the first to provide rationale for CREBBP as a biomarker for CDK4/6i response in cancer representing a new treatment paradigm for tumours that harbour CREBBP alterations that have limited therapeutic options.
2022-03-23 | PXD012098 | Pride
Project description:Loss of function mutations of the histone acetyltransferase CREBBP have recently been described at high frequencies across a spectrum of lymphoid malignancies. The multiple effects of this epigenetic regulator on developmental and homeostatic processes have been extensively studied, however, exactly how CREBBP functions as a tumour suppressor remains unclear. Here we use a murine model to demonstrate that loss of Crebbp in haematopoietic stem and progenitor cells (HSPCs) leads to increased development of B-cell lymphoproliferative disorders (LPD). We identify a pre-malignant (PM) B220+ Mac1+ stem cell which ultimately transforms to LPD and shed light on the mechanisms of malignant evolution by comparing lymphoid progenitors, pre-malignant and malignant cells at the clonal, transcriptional, epigenetic and genetic levels. We demonstrate that loss of Crebbp in HSPCs facilitates the development of lymphoid malignancies by generating a hyperproliferative population of lymphoid progenitors with an altered response to DNA-damage and enhanced self-renewal properties. Global genomic profiling revealed that epigenetic alterations observed in lymphoid progenitors correlated highly with transcriptional changes observed in frank LPD. Taken together, these findings define the tumour suppressor functions of Crebbp and shed light on the cellular origins and subsequent evolution of lymphoid malignancies.
2017-12-13 | GSE92344 | GEO
Project description:Inactivating mutations of the KMT2D methyltransferase and the CREBBP acetyltransferase are among the most common genetic alterations in B-cell lymphoma and co-occur in 40-60% of follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL) cases, suggesting they may be co-selected. Here we show that combined germinal center (GC)-specific haploinsufficiency of Crebbp and Kmt2d synergize in vivo to promote the expansion of abnormal GCs, a common pre-neoplastic event. These enzymes form a biochemical complex on selected enhancers/super-enhancers that are critical for the delivery of signals in the GC light-zone and are only corrupted upon dual Crebbp/Kmt2d loss, both in mouse GC B cells and in human DLBCLs. Moreover, we find that CREBBP directly acetylates KMT2D in GC-derived B cells. Accordingly, inactivation of CREBBP by FL/DLBCL-associated truncating and/or missense mutations abrogates its ability to catalyze KMT2D acetylation. Importantly, genetic and pharmacologic loss of CREBBP and the consequent decrease in KMT2D acetylation leads to reduced levels of H3K4me1, supporting a role for acetylation in modulating KMT2D activity. These data identify a direct biochemical and functional interaction between CREBBP and KMT2D, with implications for their role as tumor suppressors in FL/DLBCL and for the development of combinatorial therapies targeting enhancer defects induced by their loss.
2023-02-28 | GSE220255 | GEO
Project description:Purpose: Diffuse large B cell lymphomas (DLBCL) frequently harbor mutations in the histone acetyltransferase CREBBP, however their functional contribution to lymphomagenesis remains largely unknown. This study aims at elucidating and characterizing the molecular pathways affected by mutations in CREBBP. Methods: U2932, a DLBCL cell line that has wild type expression of CREBBP was manipulated by CRISPR-Cas9 strategy to mutate one allele of CREBBP and examine the pathways affected. RNA was isolated using the NucleoSping RNA Kit (Macherey-Nagel) from five wild type (CREBBP+/+) and five heterozygous clones (CREBBP+/-). RNA quality was assessed by Bioanalyzer 2100 followed by library preparation using the TruSeq RNA Sample Prep Kit v4 (Illumina). Sequencing was subsequently performed on the Illumina HiSeq 2500 instrument. RNA-seq reads were quality-checked with fastqc, which computes various quality metrics for the raw reads. RNA-seq reads were mapped to the GRCh38 reference human genome using STAR and reads were counted according to Ensembl gene annotation using the featureCounts function in the Rsubread Bioconductor package. Statistical analysis of differential expression was conducted with the DESeq2 package.
2016-11-16 | GSE89879 | GEO
Project description:Inactivating mutations of the CREBBP acetyltransferase and, at lower frequencies, its paralogue EP300 are among the most common genetic alterations in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), the two most frequent B cell malignancies. Here we uncover unexpected distinct functions for CREBBP and EP300 in the germinal center (GC), i.e. the target structure for most human B cell lymphomas. We show that these proteins modulate non-overlapping transcriptional programs that are preferentially enriched in biological functions associated with the separate anatomic compartments of the GC. Consistently, deletion of CREBBP or EP300 have opposing effects on GC formation in vivo. Nonetheless, these proteins partially compensate for each other to maintain a minimal threshold of acetyltransferase activity and guarantee homeostatic control of the GC, which is completely abrogated by their combined loss. This synthetic lethal interaction is retained in DLBCL cells, identifying an Achille’s heel in CREBBP-mutant lymphomas that could be pharmacologically targeted by using a novel, selective small molecule inhibitor of the CREBBP/EP300 bromodomain. These data shed light on the unique roles of CREBBP and EP300 in the physiology and pathology of GC B cells, and provide a proof-of-principle for the development and testing of EP300 inhibition as a therapeutic strategy in these diseases.
2020-02-19 | GSE132365 | GEO