Recurrent mutations in RNA splicing factors SF3B1, U2AF1, and SRSF2 have been reported in hematologic cancers including myelodysplastic syndromes (MDS) and chronic lymphocytic leukemia (CLL). However, SF3B1 is the only splicing associated gene to be found mutated in CLL and has been shown to induce aberrant splicing. To investigate if any other genomic aberration caused similar transcriptome changes, we clustered RNASeq samples based on an alternative 3' splice site (ss) pattern previously identified in SF3B1-mutant CLL patients. Out of 215 samples, we identified 37 (17%) with alternative 3' ss usage, the majority of which harbored known SF3B1 hotspot mutations. Interestingly, 3 patient samples carried previously unreported in-frame deletions in SF3B1 around K700, the most frequent mutation hotspot. To study the functional effects of these deletions, we used various minigenes demonstrating that recognition of canonical 3' ss and alternative branchsite are required for aberrant splicing, as observed for SF3B1 p.K700E. The common mechanism of action of these deletions and substitutions result in similar sensitivity of primary cells towards splicing inhibitor E7107. Altogether, these data demonstrate that novel SF3B1 in-frame deletion events identified in CLL result in aberrant splicing, a common biomarker in spliceosome-mutant cancers. Overall design: 13 CLL samples, 5 SF3B1 WT, 5 SF3B1 p.K700E, and 3 with in-frame deletions around the K700 position of SF3B1
Novel <i>SF3B1</i> in-frame deletions result in aberrant RNA splicing in CLL patients.
Disease, Disease stage, Subject
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BRD4 Profiling Identifies Critical Chronic Lymphocytic Leukemia Oncogenic Circuits and Reveals Sensitivity to PLX51107, a Novel Structurally Distinct BET Inhibitor.
Specimen part, Subject
View SamplesBromodomain and extra-terminal (BET) family proteins are key regulators of gene expression in cancer. Herein, we utilize BRD4 profiling to identify critical pathways involved in pathogenesis of chronic lymphocytic leukemia (CLL). BRD4 is over-expressed in CLL and is enriched proximal to genes up-regulated or de novo expressed in CLL with known function in disease pathogenesis and progression. These genes, including key members of the BCR signaling pathway, provide rationale for this therapeutic approach to identify new targets in alternative types of cancer. Additionally, we describe PLX51107, a structurally distinct BET inhibitor with novel in vitro and in vivo pharmacologic properties that emulates or exceeds the efficacy of BCR signaling agents in pre-clinical models of CLL. Herein, the discovery of the involvement of BRD4 in the core CLL transcriptional program provides a compelling rationale for clinical investigation of PLX51107 as epigenetic therapy in CLL and application of BRD4 profiling in other cancers.
BRD4 Profiling Identifies Critical Chronic Lymphocytic Leukemia Oncogenic Circuits and Reveals Sensitivity to PLX51107, a Novel Structurally Distinct BET Inhibitor.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation links the tricarboxylic acid (TCA) cycle with methionine metabolism and nuclear DNA methylation.
Specimen part, Cell line
View SamplesThe goal of the study was to understand whether mitochondrial-driven epigenetic changes regulate gene expression. Mitochondrial metabolism has been implicated in epigenetics but the extent to which this impacts gene expression is unclear. Here we show that loss of mitochondrial DNA (mtDNA) results in locus-specific alterations in histone acetylation, DNA methylation and expression of a subset of genes. Most of these changes are rescued by restoring mitochondrial electron transport in a way that maintains the oxidative tricarboxylic acid cycle, but not reactive oxygen species or ATP production, or by modulating the mitochondrial pool of acetyl-CoA. Changes in acetyl-CoA and histone acetylation precede overt mitochondrial dysfunction and significant changes in gene expression and DNA methylation. This suggests that acetyl-CoA levels signal mitochondrial status to the nucleus. Differentially expressed genes with altered histone marks or DNA methylation regulate amino acid degradation, which likely compensates for the changes in acetyl-CoA and one carbon metabolism. These have the potential to further affect methylation reactions, redox control and nucleotide levels. These results illustrate the extent to which mitochondria impact cell physiology through epigenetic remodeling.
Mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation links the tricarboxylic acid (TCA) cycle with methionine metabolism and nuclear DNA methylation.
Cell line
View SamplesWe established a mouse model, in which transcription factor Tcfap2c can be activated in an inducible and reversible manner in somatic tissues, taking advantage of the tetracycline-dependent regulatory system.
Transgenic overexpression of Tcfap2c/AP-2gamma results in liver failure and intestinal dysplasia.
Specimen part
View SamplesChronic injury in kidney transplants remains a major cause of graft loss. The aim of this study was to identify a predictive gene set capable of classifying renal grafts at risk for progressive injury due to fibrosis.The Genomics of Chronic Allograft Rejection (GoCAR) study is a prospective, multicenter study. Biopsies obtained prospectively 3 months after transplantation from renal allograft recipients (n=159) with stable renal function were analyzed for gene expression by microarray. Genes were sought which correlated with subsequent 12-month Chronic Allograft Damage Index (CADI) but neither CADI in the 3 month biopsy nor other histological or clinical parameters.
Biopsy transcriptome expression profiling to identify kidney transplants at risk of chronic injury: a multicentre, prospective study.
Specimen part
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