SiFoxA1_molecular_apocrine
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Gordon Brown
PROVIDER: E-MTAB-987 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Publications
Androgen receptor driven transcription in molecular apocrine breast cancer is mediated by FoxA1.
Robinson Jessica L L JL Macarthur Stewart S Ross-Innes Caryn S CS Tilley Wayne D WD Neal David E DE Mills Ian G IG Carroll Jason S JS
The EMBO journal 20110624 15
Breast cancer is a heterogeneous disease and several distinct subtypes exist based on differential gene expression patterns. Molecular apocrine tumours were recently identified as an additional subgroup, characterised as oestrogen receptor negative and androgen receptor positive (ER- AR+), but with an expression profile resembling ER+ luminal breast cancer. One possible explanation for the apparent incongruity is that ER gene expression programmes could be recapitulated by AR. Using a cell line ...[more]
Similar Datasets
Project description:We performed a comparision of AR binding sites as well as the histone modifications H3K27 acetylation and H3K4 monomethylation in the presence and absence of FoxA1 in the molecular apocrine breast cancer cell line, MDA-MB-453. We also probed AP2alpha binding in asynchronous MDA-MB-453 cells.
2014-04-17 | E-MTAB-1694 | biostudies-arrayexpress
Project description:We performed androgen receptor (AR) ChIP-seq after GFP control or FOXA1 over-expression in two AR driven cancer models; LNCaP prostate cancer cell line and MDA-MB-453 molecular apocrine breast cancer cell line.
2014-01-14 | E-MTAB-1749 | biostudies-arrayexpress
Project description:Androgen-stimulated growth of the molecular apocrine breast cancer is mediated by an androgen receptor (AR)-regulated transcriptional program. Through profiling the genomic licalizations of AR and its co-regulators FOXA1 and TCF7L2 in MDA-MB-453 breast cancer cells, we revealed the molecular details of the AR-centered regulatory network. We further identified that c-MYC is a key downstream target co-regulated by AR, FOXA1 and TCF7L2, and reinforces the transctiopnal activation of androgen-responsive genes in this subtype of breast cancers. MDA-MB-453 breast cancer cells were transfected with control of MYC siRNA for 48 h, followed by treatment with 10nM DHT or vehicle for 6 h. The cells were subjected to mRNA purification and library praparation for RNA-seq on Illumina HiSeq2000 platform.
2013-03-16 | E-GEOD-45202 | biostudies-arrayexpress
Project description:Breast cancer is a heterogeneous disease comprised of at least five major subtypes. Luminal subtype tumors confer a more favourable patient prognosis, which is in part, attributed to the Estrogen Receptor-alpha (ER) positivity and anti-hormone responsiveness of these tumors. Expression of the forkhead box transcription factor, FOXA1, also correlates with the luminal subtype and patient survival, but is present in a subset of ER-negative tumors. Similarly, FOXA1 is consistently expressed in luminal breast cancer cell lines even in the absence of ER. In contrast, basal breast cancer cell lines do not express FOXA1, and loss of FOXA1 in luminal cells increases migration and invasion, characteristics of the basal subtype. To delineate an ER-independent role for FOXA1 in maintaining the luminal phenotype, and hence a more favourable prognosis, we performed cDNA microarray analyses on luminal FOXA1-positive, ER-positive (MCF7, T47D) and FOXA1-positive, ER-negative (MDA-MB-453, SKBR3) cell lines in the presence or absence of transient FOXA1 silencing. This resulted in three FOXA1 transcriptomes: (1) a luminal-signature (consistent across cell lines), (2) an ER-positive signature (restricted to MCF7 and T47D) and (3) an ER-negative signature (restricted to MDA-MB-453 and SKBR3). Use of Gene Set Enrichment Analyses (GSEA) as a phenotyping tool revealed that FOXA1 silencing resulted in a transcriptome shift from luminal to basal gene expression signatures. FOXA1 binds to both luminal and basal genes within luminal breast cancer cells, suggesting that it not only transactivates luminal genes, but also represses basal-associated genes. From these results we conclude that FOXA1 controls plasticity between basal and luminal cells, playing a dominant role in repressing the basal phenotype, and thus tumor aggressiveness, in luminal breast cancer cells. Although it has been proposed that FOXA1-targeting agents may be useful for treating luminal tumors, these data suggest that this approach may promote transitions toward a more aggressive cancer. FOXA1 siRNA treated breast cell lines compared directly to nonspecific siRNA treated cell lines using Agilent 4X44 microarrays.
2012-03-09 | E-GEOD-31003 | biostudies-arrayexpress
Project description:Breast cancer is a heterogeneous disease and several distinct subtypes exist based on differential gene expression patterns. Molecular apocrine tumours were recently identified as an additional subgroup, characterised as oestrogen receptor negative and androgen receptor positive (ER_ AR+), but with an expression profile resembling ER+ luminal breast cancer. One possible explanation for the apparent incongruity is that ER gene expression programmes could be recapitulated by AR. Using a cell line model of ER_ AR+ molecular apocrine tumours (termed MDA-MB-453 cells), we map global AR binding events and find a binding profile that is similar to ER binding in breast cancer cells. We find that AR binding is a near-perfect subset of FoxA1 binding regions, a level of concordance never previously seen with a nuclear receptor. AR functionality is dependent on FoxA1, since silencing of FoxA1 inhibits AR binding, expression of the majority of the molecular apocrine gene signature and growth cell growth. These findings show that AR binds and regulates ER cis-regulatory elements in molecular apocrine tumours, resulting in a transcriptional programme reminiscent of ER-mediated transcription in luminal breast cancers.
2012-02-18 | E-MTAB-986 | biostudies-arrayexpress
Project description:Androgen-stimulated growth of the molecular apocrine breast cancer is mediated by an androgen receptor (AR)-regulated transcriptional program. Through profiling the genomic licalizations of AR and its co-regulators FOXA1 and TCF7L2 in MDA-MB-453 breast cancer cells, we revealed the molecular details of the AR-centered regulatory network. We further identified that c-MYC is a key downstream target co-regulated by AR, FOXA1 and TCF7L2, and reinforces the transctiopnal activation of androgen-responsive genes in this subtype of breast cancers. AR and FOXA1 ChIP-seq were performed in MDA-MB-453 breast cancer cells with treatment of 5a-dihydrotestosterone (DHT) for 16 h. TCF7L2 ChIP-seq was performed in MDA-MB-453 cells treated with vehicle or DHT for 16 h, respectively. MYC ChIP-seq was performed in MDA-MB-453 cells following 6 h DHT stimulation.
2013-03-16 | E-GEOD-45201 | biostudies-arrayexpress
Project description:To study the biological and functional role of vimentin in maintenance of the mesenchymal phenotype of mammary epithelial cells, vimentin was silenced in the non-transformed MCF10A cells and vimentin-dependent changes in gene expression were analyzed. Scrambled is the siScr-transfected control with two replicates; KD the sample with vimentin knockdown, also two replicates.
2010-11-18 | E-GEOD-17802 | biostudies-arrayexpress
Project description:FOXA1 is a transcription factor which aids AR function in prostate. There is controversary over the effect of high FOXA1 level has on prostate cancer so we forced the overexpression in the LNCaP prostate cancer cell line. LNCaP prostate cancer cell line was transfected with GFP control plasmid or plasmid containing FOXA1 full length cDNA. The effect on gene expression was assessed by microarray.
2014-01-03 | E-GEOD-49153 | biostudies-arrayexpress
Project description:The scaffold attachment factors SAFB1 and SAFB2 are paralogs, which are involved in cell cycle regulation, apoptosis, differentiation, and stress response. They have been shown to function as estrogen receptor co-repressors, and there is evidence for a role in breast tumorigenesis. To identify their endogenous target genes in MCF-7 breast cancer cells, we utilized gene expression array analysis, which was set up in a two-by-four design, with vehicle and estrogen treatment, and control, SAFB1, SAFB2, and SAFB1/SAFB2 siRNA as variables. Using custom chips containing 1.5 kb upstream regulatory region, we identified 541 SAFB1/SAFB2 binding sites in promoters of known genes, with significant enrichment on chromosome 1 and 6. Gene expression analysis revealed that the majority of target genes were induced in the absence of SAFB1 or SAFB2, and less were repressed. In contrast to SAFB2, which shared most of its target genes with SAFB1, SAFB1 had many unique target genes, most of them involved in regulation of the immune system. A subsequent analysis of the estrogen treatment group revealed that twelve percent of estrogen-regulated genes were dependent on SAFB1, with the majority being estrogen-repressed genes. These were primarily genes involved in apoptosis, such as BBC3, NEDD9, and OPG. Thus, this study confirms SAFB1/SAFB2âs primary role as co-repressors, and also uncovers a previously unknown role for SAFB1 in regulation of immune genes, and in estrogen-mediated repression of genes. To identify transcripts which were altered upon decrease of SAFB1 or SAFB2 expression we performed gene expression array analysis in MCF-7 cells. A secondary goal was to identify ERα-target genes for which estrogen regulation was dependent upon SAFB expression. We also added an experimental group in which we co-transfected siRNAs targeting both SAFB1 and SAFB2, which allowed us to address the question of interactions between the two paralogs. We therefore set up an experiment reflecting a 2x4 design, with a total of eight experimental groups.
2010-02-21 | E-GEOD-15548 | biostudies-arrayexpress
Project description:Estrogen Receptor ? (ER?) has central role in hormone-dependent breast cancer and its ligand-induced functions have been extensively characterized. However, evidence exists that ER? has functions which are independent of ligands. In the present work, we investigated the binding of ER? to chromatin in absence of ligands, and its function(s) on gene regulation. We demonstrated that in MCF7 breast cancer cells unliganded ER? binds to more than four thousands chromatin sites. Unexpectedly, although almost entirely comprised in the larger group of estrogen-induced binding sites, we found that unliganded-ER? binding is specifically linked to genes with developmental functions, as compared to estrogen-induced binding. Moreover, we found that siRNA-mediated downregulation of ER? in absence of estrogen is accompanied by changes in the expression levels of hundreds of coding and noncoding RNAs. Downregulated mRNAs showed enrichment in genes related to epithelial cell growth and development. Stable ER? downregulation using shRNA, which caused cell-growth arrest, was accompanied by increased H3K27me3 at ER? binding sites. Finally, we found that FOXA1 and AP2? binding to several sites is decreased upon ER? silencing, suggesting that unliganded ER? participates, together with other factors, to the maintenance of the luminal-specific cistrome in breast cancer cells. Examination of unligandend estrogen receptor alpha (apoER?) DNA interactions in control and ER? siRNA treated MCF7 cells.
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