Genes encoding subunits of SWI/SNF (BAF) chromatin remodeling complexes are collectively altered in over 20% of all human malignancies, but the mechanisms by which these complexes alter chromatin to modulate transcription and control cell fate are poorly understood. Utilizing both loss-of-function and gain-of-function approaches, here we show that SWI/SNF complexes are preferentially targeted to distal enhancers and interact with p300 to regulate transcription via modulation of histone H3 lysine 27 acetylation. We identify a greater requirement for SWI/SNF at typical enhancers than at most super-enhancers and at enhancers in untranscribed regions than in transcribed regions. Our data further demonstrate that SWI/SNF-dependent distal enhancers are essential for controlling expression of genes linked to developmental processes. Our findings thus establish SWI/SNF complexes as regulators of the enhancer landscape and provide insight into the roles of SWI/SNF in cellular fate control. Overall design: RNA-seq in Mouse Embryonic Fibroblasts in WT condition and for knockouts of different SWI/SNF complex subunits.
The SWI/SNF chromatin remodelling complex is required for maintenance of lineage specific enhancers.
No sample metadata fields
View SamplesSMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1. Overall design: RNA-seq in six Smarcb1 deficient rhabdoid tumor cell lines, before and after Smarcb1 re-expression.
SMARCB1-mediated SWI/SNF complex function is essential for enhancer regulation.
No sample metadata fields
View SamplesSMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1. Overall design: RNA-seq for three primary Rhabdoid tumor samples
SMARCB1-mediated SWI/SNF complex function is essential for enhancer regulation.
No sample metadata fields
View SamplesType I interferons were discovered as the primary antiviral cytokines and are now known to serve critical functions in host defense against bacterial pathogens. Accordingly, established mediators of interferon antiviral activity may mediate previously unrecognized antibacterial functions. RNase-L is the terminal component of an RNA decay pathway that is an important mediator of interferon-induced antiviral activity. Here we identify a novel role for RNase-L in the host antibacterial response. RNase-L-/- mice exhibited a dramatic increase in mortality following
An essential role for the antiviral endoribonuclease, RNase-L, in antibacterial immunity.
No sample metadata fields
View SamplesHepatocellular carcinoma (HCC) is a highly prevalent and deadly disease world-wide. The survival of HCC patients is usually very poor due to the lack of efficient anti-cancer drugs
Synthesis and bio-molecular study of (+)-N-Acetyl-α-amino acid dehydroabietylamine derivative for the selective therapy of hepatocellular carcinoma.
Cell line, Treatment
View SamplesMalignant mesothelioma (MM) is an asbestos-related malignancy and largely unresponsive to conventional chemotherapy or radiotherapy. Novel, more effective therapeutic strategies are needed for this fatal disease. We performed microarray analysis of MM using Affymetrix Human U133 Plus 2.0 array. Aberrant expression of the genes participating in semaphorin signaling were detected in malignant mesothelioma cells. All MM cells downregulated the expression of more than one gene for SEMA3B, 3F, and 3G when compared with Met5a, a normal pleura-derived cell line. In 12 of 14 epithelioid MM cells, the expression level of SEMA3A was lower than that in Met5a. An augmented expression of VEGFA was detected in half of the MM cells. The expression ratio of VEGFA/SEMA3A was significantly higher in the epithelioid MMs than in Met5a and the non-epithelioid MMs. Next, gene expression profiling for the polycomb and trithorax group genes revealed that expression of BAP1, the catalytic subunit of the polycomb repressive deubiquitinase complex, and many trithorax group genes was downregulated in MMs compared with the expression of the same genes in Met5a cells. Perturbation of the polycombtrithorax balance plays a significant role in the pathogenesis of malignant mesothelioma.
Frequent deletion of 3p21.1 region carrying semaphorin 3G and aberrant expression of the genes participating in semaphorin signaling in the epithelioid type of malignant mesothelioma cells.
Sex, Age, Specimen part, Cell line
View SamplesBirt-Hogg-Dube (BHD) syndrome is an autosomal dominant disorder characterized by hamartomas of skin follicles, cystic lung disease, and renal neoplasia. Affected individuals carry heterozygous mutations in Folliculin (FLCN), a tumor suppressor gene that becomes biallelically inactivated in kidney tumors by second-hit mutations. Similar to other factors implicated in kidney malignancies, Folliculin has been shown to modulate activation of mammalian target of rapamycin (mTOR). However, its precise in vivo function is largely unknown because germline deletion of Flcn results in early embryonic lethality in animal models. We here describe mice deficient in the newly characterized Folliculin-Interacting Protein 1 (Fnip1). In contrast to Flcn, Fnip1-/- mice develop normally, are not susceptible to kidney neoplasia, but display a striking pro-B cell block that is independent of mTOR activity. We show that this developmental arrest results at least in part from impaired V(D)J recombination and caspase-induced cell death, and that pre-recombined V(D)J and Bcl2 transgenes reconstitute pre-B and mature B cell populations respectively. We also demonstrate that conditional deletion of Flcn recapitulates the pro-B cell arrest of Fnip1-/- mice. Our studies thus demonstrate that the Flcn-Fnip complex deregulated in BHD syndrome is absolutely required for B cell differentiation and that it functions both through mTOR dependent and independent pathways. Overall design: RNASeq data for two pro-B cell subsets (fraction B and CC'') isolated from wt and Fnip1-/- mice
The folliculin-FNIP1 pathway deleted in human Birt-Hogg-Dubé syndrome is required for murine B-cell development.
Cell line, Subject
View SamplesC57BL/6 mice were infected with the GS strain of G. duodenalis and total RNA prepared from the duodenum on day 10. Age matched controls were compared using Affy chips to determine changes in gene expression induced by infection.
Transcriptomic analysis of the host response to Giardia duodenalis infection reveals redundant mechanisms for parasite control.
Age, Specimen part
View SamplesAlternative splicing and mRNA editing are known to contribute to transcriptome diversity. Although alternative splicing is pervasive and known to contribute to a variety of pathologies, including cancer, the genetic context for individual differences in isoform usage is still evolving. Similarly, although mRNA editing is ubiquitous and associated with important biological processes such as intracellular viral replication and cancer development, individual variations in and the genetic transmissibility of mRNA editing are equivocal. Here, we have used linkage analysis to show that both mRNA editing and alternative splicing are regulated by the macrophage genetic background and environmental cues. We show that distinct loci, potentially harboring variable splice factors, regulate the splicing of multiple transcripts. Additionally, we show that individual genetic variability at the Apobec1 locus results in differential rates of C-to-U(T) editing in murine macrophages; with mouse strains expressing mostly a truncated isoform of Apobec1 exhibiting lower rates of editing. As a proof of concept, we have used linkage analysis to identify 36 high confidence novel edited sites. These results provide a novel and complementary method that can be used to identify C-to-U editing sites in individuals segregating at specific loci and show that, beyond individual DNA sequence and structural changes, differential isoform usage and mRNA editing can contribute to intra-species genomic and phenotypic diversity. Overall design: Bone marrow derived macrophages (BMDM) from female AxB/BxA mice were left unstimulated or stimulated with IFNG/TNF, or CpG for 18 hrs or infected with infected with type II (Pru A7) for 8 hrs. The transcriptional response was then measured using the illumina RNA-seq protocol on an illumuna HiSeq 2000.
The genetic basis for individual differences in mRNA splicing and APOBEC1 editing activity in murine macrophages.
Age, Specimen part, Cell line, Treatment, Subject
View SamplesAnalysis of the genes and cellular signalling cascades mediating the response of SCN slices to vasoactive intestinal peptide (VIP). Primary goal was to find novel genes that may be involved in circadian phase shifting for further study. Promoter analysis of significantly regulated genes and gene ontology analysis would provide information into pathways VIP acts through in the SCN.
Vasoactive intestinal peptide controls the suprachiasmatic circadian clock network via ERK1/2 and DUSP4 signalling.
Specimen part
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