This 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 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 SamplesMethods for identifying protein-protein interactions have mostly been limited to tagged exogenous expression approaches. We now establish a rapid, robust and comprehensive method for finding interacting proteins using endogenous proteins from limited cell numbers. We apply this approach called Rapid IP-Mass Spectrometry of Endogenous proteins (RIME) to identify ER, FoxA1 and E2F4 interacting proteins in breast cancer cells. From small numbers of starting cells, we find a comprehensive collection of known ER, FoxA1 and E2F4 targets, plus a number of novel unexpected interactors. One of the most ER (and FoxA1) associated interactors is GREB1, an estrogen induced gene with almost no known function. We apply RIME, in parallel with ER ChIP-seq, to identify ER protein interactors and ER binding events from solid tumor xenografts, resulting in the validation of the ER-GREB1 interactions. Furthermore, we establish a method for identifying endogenous interacting proteins from solid primary breast cancer samples, whih we apply to validate ER interactions with GREB1 and additional co-factors. Mechanistically, we show that GREB1 is recruited with ER to the chromatin where it functions as an essential estrogen-mediated regulatory factor required for effective ER transcriptional activity. Our novel approach enables, for the first time, the ability for discovery and validation of protein-protein interactions in whole tissue and solid tumors, revealing significant insight into ER regulatory factors.
Endogenous purification reveals GREB1 as a key estrogen receptor regulatory factor.
Cell line, Treatment
View SamplesThe basic unit of genome packaging is the nucleosome, and nucleosomes have long been proposed to restrict DNA accessibility both to damage and to transcription. However, nucleosome number in cells was considered fixed, and no condition was described where nucleosome number was reduced. We show here that mammalian cells lacking High Mobility Group Box 1 protein (HMGB1) contain a reduced amount of core, linker and variant histones, and a correspondingly reduced number of nucleosomes. Yeast nhp6 mutants lacking NHP6A and B proteins, which are related to HMGB1, also have a reduced amount of histones and fewer nucleosomes. Nucleosome limitation in both mammalian and yeast cells increases the sensitivity of DNA to damage, increases transcription globally, and the relative expression of about 10% of genes. In yeast nhp6 cells the loss of more than one nucleosome in four does not affect the location of nucleosomes and their spacing, but nucleosomal occupancy. The decrease in nucleosomal occupancy is non-uniform, and our results can be modelled assuming that different nucleosomal sites compete for the available histones: sites with high affinity are almost always packaged into nucleosomes both in wt and nucleosome-depleted cells, whereas sites with low affinity are less frequently packaged in nucleosome-depleted cells. We suggest that by modulating the occupancy of nucleosomes histone availability may constitute a novel layer of epigenetic regulation.
Substantial histone reduction modulates genomewide nucleosomal occupancy and global transcriptional output.
No sample metadata fields
View SamplesTh17 cells were sorted ex vivo from PB of healthy donors as CD4+CD161+CCR6+CXCR3-. Following, cells were transduced with a lentiviral vector carrying the Eomes gene or with an empty vector. Infected cells were then enriched by MACS separation using the reporter gene NGFR as selection marker. Finally, cells were frozen for RNA analysis.
Eomes controls the development of Th17-derived (non-classic) Th1 cells during chronic inflammation.
Cell line
View SamplesIn this study we applied differential gene expression analysis to exfoliated human urothelia obtained from patients of known bladder disease status. Selected targets from the microarray data were validated in an independent set of samples using a quantitative PCR approach.
A candidate molecular biomarker panel for the detection of bladder cancer.
Specimen part, Disease
View SamplesMutants in the Drosophila gene lethal (3) malignant brain tumor cause malignant growth in the larval brain. This data shows the changes in gene expression profile associated to mutations in l(3)mbt, both in situ in third instar larval brains and in tumors cultured for 1 5 and 10 (T1, T5, T10) rounds of allograft culture
Ectopic expression of germline genes drives malignant brain tumor growth in Drosophila.
No sample metadata fields
View SamplesTranscriptomic analysis of ICM and TE from in vivo-derived equine blastocysts using Illumina sequencing technology Overall design: RNA was extracted from individual equine blastocyst ICM and TE (Arcturus Picopure), cDNA was synthesized and amplified (Nugen Ovation V2) and indexed libraries were created for sequencing (TruSeq DNA V1)
RNA-seq transcriptome profiling of equine inner cell mass and trophectoderm.
Specimen part, Subject
View SamplesBJAB cells over expressing KSHV PAN RNA
Regulation of viral and cellular gene expression by Kaposi's sarcoma-associated herpesvirus polyadenylated nuclear RNA.
No sample metadata fields
View Samples