MicroRNAs (miRNAs) have emerged as novel cancer genes. In particular, the 17~92 cluster of miRNAs is highly expressed in haematopoietic cancers and promotes lymphomagenesis in vivo1,2. Clinical use of these findings hinges on isolating the oncogenic activity within the 17~92 cluster and defining its relevant target genes. Here we show that miR-19 is sufficient to promote leukaemogenesis in Notch1 induced T-cell lymphoblastic leukaemia (T-ALL) in vivo. Consistent with the pathogenic importance of this interaction, we report a novel translocation targeting the 17~92 miRNA cluster coinciding with a second rearrangement that activates Notch1 in T-ALL. To identify the miR-19 targets responsible for its oncogenic action, we conducted a large-scale short-hairpin RNA (shRNA) screen for genes whose knockdown could phenocopy miR-19. Strikingly, the results of this screen were enriched for miR-19 target genes, and included Bim (Bcl2L11)1,3, AMP-activated kinase (Prkaa1), and the tumour suppressor phosphatases Pten and PP2A (Ppp2r5e). Hence, an unbiased, functional genomics approach reveals a coordinate clamp down on several regulators of PI3K-related survival signals by the leukaemogenic miR-19.
Genome-wide RNA-mediated interference screen identifies miR-19 targets in Notch-induced T-cell acute lymphoblastic leukaemia.
Cell line
View SamplesWe used microarrays to detail gene expression profile of several follicular lymphoma patient samples with different grades
Frequent disruption of the RB pathway in indolent follicular lymphoma suggests a new combination therapy.
Specimen part
View SamplesWe performed RNA-seq on purified squamous cell carcinoma stem cells (SCC-SCs) from primary mouse skin tumors transduced with TGF-beta reporter. Overall design: SCC-SCs were purified based on cell surface marker expression integrin alpha6 and CD44, after lineage negative selection, and separated by fluorescent TGF-beta reporter expression.
TGF-β promotes heterogeneity and drug resistance in squamous cell carcinoma.
No sample metadata fields
View SamplesIn higher eukaryotes, an important mechanism to tune translation in different tissues and conditions is mTORC1-dependent regulation of tRNAs transcription by RNA polymerase III (Pol III), as the relative amount of tRNAs tightly coordinates with the translational needs of the cell. mTORC1 contributes to regulate protein synthesis through its direct substrate MAF1, which functions as a negative regulator of Pol III transcription in response to stimuli such as serum starvation or rapamycin treatment. Here, we applied ChIP-seq to examine the Pol III occupancy profile in human fibroblasts and report evidence of a genome wide, MAF1-dependent coordinated response to favorable or stress growth conditions. Strikingly, while a set of genes is extremely responsive in terms of Pol III binding, other genes are mostly unperturbed, yet associated with transcriptionally engaged polymerases as revealed by nascent EU-labeled RNA-seq (neuRNA-seq). As shown by DamIP-seq, the responsiveness of a subset of genes is tightly connected to the rapid and transient interaction of MAF1 with DNA-bound Pol III. Overall design: We performed duplicate ChIP-seq experiments for the Rpc4 (POLR3D) subunit of RNA polymerase III in IMR90hTert cells grown in the presence of fetal bovine serum (FBS), serum starved (SS), serum starved and treated with insulin (SS+I), serum starved and treated with insulin and rapamycin (SS+R+I). Additional ChIP-seq profiles were generated in cells treated with MAF1 siRNAs and serum starved. MAF1 binding was addressed by DamIP-seq, using two replicates per clone of IMR90hTert cells expressing HA-tagged MAF1-DamK9A (2 different clones) or EGFP-DamK9A (2 different clones). To monitor dynamic transcription profiles we did neusRNA-seq in IMR90hTert cells EU-labeled or mock (DMSO)-labeled. For both DamIP-seq and neusRNA-seq, cells were either unperturbed or serum starved.
Human MAF1 targets and represses active RNA polymerase III genes by preventing recruitment rather than inducing long-term transcriptional arrest.
No sample metadata fields
View SamplesHuR-deficient cells showed the decreased expression of genes involved in chemotaxis, cell proliferation and signal transduction.
Hu Antigen R Regulates Antiviral Innate Immune Responses through the Stabilization of mRNA for Polo-like Kinase 2.
Specimen part, Cell line
View SamplesHistone deacetylases (HDACs) and acetyltransferases control the epigenetic regulation of gene expression through modification of histone marks. Histone deacetylase inhibitors (HDACi) are small molecules that interfere with histone tail modification thus altering chromatin structure and epigenetically controlled pathways. They promote apoptosis in proliferating cells and are promising anti-cancer drugs. While some HDACis have already been approved for therapy and others are in different phases of clinical trials, the exact mechanism of action of this drug class remains elusive. Previous studies have shown that HDACis cause massive changes in chromatin structure but only moderate changes in gene expression. To which extent these changes manifest at the protein level has never been investigated on a proteome-wide scale. Here, we have studied HDACi-treated cells by large-scale mass spectrometry based proteomics. We show that HDACi treatment affects primarily the nuclear proteome and induces a selective decrease of bromodomain containing proteins (BCPs), the main readers of acetylated histone marks. By combining time-resolved proteome and transcriptome profiling, we show that BCPs are affected at the protein level as early as 12 hours after HDACi treatment and that their abundance is regulated by a combination of transcriptional and post-transcriptional mechanisms. Using gene silencing, we demonstrate that the decreased abundance of BCPs is sufficient to mediate important transcriptional changes induced by HDACi. Our data reveals a new aspect of the mechanism of action of HDACi that is mediated by an interplay between histone acetylation and the abundance of BCPs.
Histone Deacetylase Inhibitors (HDACi) Cause the Selective Depletion of Bromodomain Containing Proteins (BCPs).
Cell line, Treatment, Time
View SamplesMicroRNA 155 (miR-155) has been shown to regulate the gene expression of important players of physiological and pathological processes, like hematopoietic lineage differentiation, immunity and inflammation, viral infections, cancer and cardiovascular diseases, among others. Degranulation is an event in which mast cells, upon activation of the FceRI, release their granule content rich in vasoactive amines, proteases and TNFa. Additionally activation of the receptor promotes de novo synthesis of cytokines, chemokines and growth factors. Analysis of bone marrow derived mast cells (BMMC) deficient in miR-155 showed a significant increase in FceRI mediated degranulation and in the release of cytokines like TNFa, IL-6 and IL-13. In addition miR 155-/- mice presented higher anaphylaxis reactions compared to WT mice. Gene expression analysis of BMMC was performed in order to identify intermediaries of FceRI mediated degranulation under the control of miR-155. The results indicate that miR-155 regulates negatively the expression of the regulatory subunits of the kinase PI3Kgamma, Pik3r5 (p101) and Pik3r6 (p84, p87PIKAP), involved in Ca+ influx and degranulation.
miRNA-155 controls mast cell activation by regulating the PI3Kγ pathway and anaphylaxis in a mouse model.
Specimen part
View SamplesThis study was designed to examine the requirement for the p63 transcription factor in Squamous Cell Carcinoma (SCC) tumor maintenance in an in vivo murine system. A tamoxifen-inducible Keratin 14-driven Cre recombinase transgene was used to conditionally excise p63 in advanced murine SCC tumors. These data show the context-dependent regulation of p63 target genes in cancer.
FGFR2 signaling underlies p63 oncogenic function in squamous cell carcinoma.
No sample metadata fields
View SamplesIdentify differentially expressed genes related to the neurodegenerative process in a new animal model of hepatic encephalopathy (HE).
Cerebellar neurodegeneration in a new rat model of episodic hepatic encephalopathy.
Specimen part, Treatment
View SamplesAging is associated with the decline of protein, cell, and organ function. Here, we use an integrated approach to characterize gene expression, bulk translation, and cell biology in the brains and livers of young and old rats. We identify 468 differences in protein abundance between young and old animals. The majority are a consequence of altered translation output, that is, the combined effect of changes in transcript abundance and translation efficiency. In addition, we identify 130 proteins whose overall abundance remains unchanged but whose sub-cellular localization, phosphorylation state, or splice-form varies. While some protein-level differences appear to be a generic property of the rats' chronological age, the majority are specific to one organ. These may be a consequence of the organ's physiology or the chronological age of the cells within the tissue. Taken together, our study provides an initial view of the proteome at the molecular, sub-cellular, and organ level in young and old rats. Overall design: RNA-Seq and ribosome profiling from matched young and old rat liver and brain
Integrated Transcriptome and Proteome Analyses Reveal Organ-Specific Proteome Deterioration in Old Rats.
No sample metadata fields
View Samples