p21 (CDKN1A) expression from an IPTG-inducible promoter in HT1080 p21-9 cells was previously shown to inhibit a set of genes, many of which are involved in cell cycle progression, and to upregulate another set of genes, some of which have been implicated in cancer and age-related diseases. We have now developed Senexin A, a small-molecule inhibitor of p21-induced transcription, which we found to be a selective inhibitor of CDK8 and CDK19. Here we tested the effect of Senexin A on the induction and inhibition of transcription by p21.
Cyclin-dependent kinase 8 mediates chemotherapy-induced tumor-promoting paracrine activities.
Specimen part
View SamplesHeat shock timecourse RNAseq, 3T3 cells
Widespread inhibition of posttranscriptional splicing shapes the cellular transcriptome following heat shock.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
FOXA1 is a key determinant of estrogen receptor function and endocrine response.
Cell line, Treatment
View SamplesEstrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts.
FOXA1 is a key determinant of estrogen receptor function and endocrine response.
Cell line, Treatment
View SamplesTranscriptional profile of PCSC spheres in SCM-1% KO (stem-like cells) vs adherent cultures in PCSC-Celprogen medium (differentiated-like cells)
Genomic profiling of tumor initiating prostatospheres.
Specimen part, Cell line
View SamplesEstrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts.
FOXA1 is a key determinant of estrogen receptor function and endocrine response.
Treatment
View SamplesThe culture of neural stem cells (NSCs) as floating neurospheres has become widely used as an experimental model to analyse the properties of NSCs. Although the neurosphere model has existed for two decades, there is still no standard protocol to grow NSCs in this way. Thus, we have analysed the consequences of the frequency of growth factor (FGF-2 and EGF) addition to embryonic and adult olfactory bulb stem cells (eOBSCs and aOBSCs) cultures, specifically in terms of proliferation, cell cycle progression, death and differentiation, as well as on global changes in gene expression and signaling pathways. We found that addition of FGF-2 and EGF every two or four days rather than daily significantly reduces the volume of the neurospheres and the total number of cells, changes that were more evident in aOBSC than in eOBSC cultures. The reduction in neurosphere size was mainly due to an increase in cell death and occurs without major changes in the cell cycle parameters tested. Moreover, partial deprivation of FGF-2 and EGF produces a mild increase in aOBSC differentiation during the proliferative phase. Remarkably, these effects were accompanied by a significant upregulation in the expression of genes involved in cell death regulation (Cryab), lipid catabolic processes (Pla2g7), cell adhesion (Dscaml1), cell differentiation (Dscaml1, Gpr17, S100b) and signal transduction (Gpr17, Ndrg2), among others. These findings support that continuous supply of FGF-2 and EGF is critical to maintain the viability/survival of NSCs in culture and reveals novel molecular hallmarks of NSC maintenance/survival and expansion in response to these growth factors.
A global transcriptome analysis reveals molecular hallmarks of neural stem cell death, survival, and differentiation in response to partial FGF-2 and EGF deprivation.
Specimen part
View SamplesThroughout postnatal life in mammals, neural stem cells (NSCs) are located in the subventricular zone (SVZ) of the lateral ventricles. The greatest diversity of neuronal and glial lineages they generate occurs during early postnatal life in a region-specific manner. In order to evaluate potential heterogeneity in the NSC pool, we microdissected the dorsal and lateral SVZ at different postnatal ages and isolated NSCs and their immediate progeny based on their expression of Hes5-EGFP/Prominin1 and Ascl1-EGFP, respectively. Whole genome comparative transcriptome analysis revealed transcriptional regulators as major hallmarks that sustain postnatal SVZ regionalization. Manipulation of single genes encoding for locally enriched transcription factors influenced NSC specification indicating that the fate of regionalized postnatal SVZ NSCs can be readily modified . These findings reveal functional heterogeneity of NSCs in the postnatal SVZ and provide targets to recruit region-specific lineages in regenerative contexts.
Transcriptional Hallmarks of Heterogeneous Neural Stem Cell Niches of the Subventricular Zone.
Specimen part
View SamplesSynthesis and accumulation of seed storage proteins (SSPs) is an important aspect of the seed maturation program. Genes encoding SSPs are specifically and highly expressed in the seed during maturation. However, the mechanisms that repress the expression of these genes in leaf tissue are not well understood. To gain insight into the repression mechanisms, we have performed a transgenic screening for mutants that express SSPs in leaves. Here we show that mutations of BRAHMA (BRM), a SNF2 chromatin remodelling ATPase, cause the ectopic expression of a subset of SSPs and other embryogenesis related genes in leaf tissue. Consistent with the notion that such SNF2-like ATPases form protein complexes in vivo, we observed similar phenotypes for mutations of AtSWI3C, a BRM interacting partner, and BSH, a SNF5 homolog and essential SWI/SNF subunit. Further, we present chromatin immunoprecipitation evidence that BRM is recruited to the promoters of a number of embryogenesis genes including the 2S genes, which are expressed/elevated in brm leaves. Consistent with its role in nucleosome remodelling, BRM appears to control the chromatin structure of the At2S2 promoter. These results show that a BRM-containing chromatin remodelling ATPase complex is involved in the direct repression of SSPs in leaf tissue.
The Arabidopsis BRAHMA chromatin-remodeling ATPase is involved in repression of seed maturation genes in leaves.
No sample metadata fields
View SamplesIntragenic microRNAs (miRNAs), including both intronic and exonic miRNAs, accounting approximately 50% of total mammalian miRNAs. Previous studies showed that intragenic miRNAs are often co-expressed with their host genes, and thus it was believed that intragenic miRNAs and their host genes are derived from the same primary transcripts. However, we provide evidence to show here that the observations from previous studies might be biased due to the small number and the predominance of "broadly conserved" intronic miRNAs they studied.
Young intragenic miRNAs are less coexpressed with host genes than old ones: implications of miRNA-host gene coevolution.
Disease, Disease stage, Cell line
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