Elk1 Directs a Critical Component of Growth Signaling by the Androgen Receptor in Prostate Cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE34589 | GEO | 2013/05/02
SECONDARY ACCESSION(S): PRJNA150495
REPOSITORIES: GEO
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Project description:Elk1 directs selective gene induction that is a substantial and critical component of growth signaling by AR in PC cells. Gene expression in LNCaP cells was determined in androgen-depleted medium in response to R1881 in ELK1 knock down (via AR shRNA) or in cells treated with control shRNA.
2013-05-02 | E-GEOD-34589 | biostudies-arrayexpress
Project description:The androgen receptor (AR) is essential for diverse aspects of prostate development and function. Molecular mechanisms by which prostate cancer (PC) cells redirect AR signaling to genes that primarily support growth are unclear. A systematic search for critical AR-tethering proteins led to ELK1, an ETS transcription factor of the ternary complex factor subfamily. Although genetically redundant, ELK1 was obligatory for AR-dependent growth and clonogenic survival in both hormone-dependent PC and castration-recurrent PC cells but not for AR-negative cell growth. AR required ELK1 to up-regulate a major subset of its target genes that was strongly and primarily enriched for cell growth functions. AR functioned as a coactivator of ELK1 by association through its A/B domain, bypassing the classical mechanism of ELK1 activation by phosphorylation and without inducing ternary complex target genes. The ELK1-AR synergy per se was ligand-independent, although it required ligand for nuclear localization of AR as targeting the AR A/B domain to the nucleus recapitulated the action of hormone; accordingly, Casodex was a poor antagonist of the synergy. ELK3, the closest substitute for ELK1 in structure/function and genome recognition, did not interact with AR. ELK1 thus directs selective and sustained gene induction that is a substantial and critical component of growth signaling by AR in PC cells. The ELK1-AR interaction offers a functionally tumor-selective drug target.
| S-EPMC3630885 | biostudies-other
Project description:Alpha lipoic acid is reported to inhibit neutrophil lineage determination by targeting transcription factor ELK1 in granulocyte-monocyte progenitors. Here, we provide new evidence of alpha lipoic acid in promoting erythroid differentiation by targeting transcription factor ELK1 in CD34+CD371– hematopoietic stem progenitor cells. Over expression of both L-ELK1 and S-ELK1 greatly inhibit erythroid cell differentiation, but not knocking down of ELK1. Thus, RNAseq of CD34+CD123+CD38+CD371– HSPCs is performed to dissect the molecular mechanism of ELK1 in blocking erythrocyte differentiation.
2023-06-01 | GSE217887 | GEO
Project description:Chromatin immunoprecipitation of ELK1 in MCF10A cells detected by SOLiD sequencing
2012-08-20 | E-MTAB-830 | biostudies-arrayexpress
Project description:ELK1 is a well-known target of the ERK branch (EGF-responsive) of the MAP kinase pathway. This transcription profiling experiment studied the effects of ELK1 depletion by siRNA and subsequent EGF stimulation.
2012-07-20 | E-MEXP-3407 | biostudies-arrayexpress
Project description:The androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC), and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent (including constitutively active AR splice variants) mechanisms highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA2 as a regulator of AR signaling and a novel therapeutic target in PC. We demonstrate that GATA2 directly promotes AR expression (both full-length and splice variant), resulting in a strong positive correlation between GATA2 and AR expression in PC (cell lines and patient specimens). Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of AR (both full-length and splice variant). GATA2 co-localizes with AR and FOXA1 on chromatin to enhance recruitment of steroid receptor coactivators (SRCs) and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted for worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of AR (both full-length and splice variant) and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a “first-in-field” approach to target AR expression and function and improve outcomes in CRPC. LNCaP cells were transfected with control siRNA (3), GATA2 siRNA (3) or AR siRNA for 72 hours.
2015-01-21 | E-GEOD-63539 | biostudies-arrayexpress
Project description:The chromodomain helicase DNA binding protein CHD8 is among the most frequently found de-novo mutations in autism. Unlike other autism-risk genes, CHD8 mutations appear to be fully penetrant. Despite this prominent disease involvement, relatively little is known about its molecular function. Based on sequence homology, CHD8 is believed to be a chromatin regulator but mechanisms for its genomic targeting and its function on chromatin are unclear. Here, we developed a human cell model carrying conditional CHD8 loss-of-function alleles. Remarkably, while undifferentiated human embryonic stem (ES) cells required CHD8 for survival, postmitotic neurons survived following CHD8 depletion. Chromatin accessibility revealed that CHD8 is a highly potent and general chromatin activator, enhancing transcription of its direct target genes. We also found that CHD8 genomic binding in human neurons was significantly enriched at ELK1 DNA binding motifs as previously found in other cell types. Given its prominent role as effector molecule of the MAPK/ERK pathway, we decided to further explore its relationship with CHD8. ELK1 motif-containing CHD8 binding sites showed a higher degree of chromatin opening function of CHD8 than other CHD8 binding sites. Moreover, ELK1 was required for CHD8 binding to Elk1-containing sites, but not other sites. Finally, the anti-apoptotic function of CHD8 in human ES cells could be rescued by depletion of ELK1 and the enhancement of neurogenesis by ELK1 was dependent on presence of CHD8. In summary, our results establish a clear role of CHD8 for chromatin opening and transcriptional activation and a molecular and functional interdependence of CHD8 and ELK1. These data imply the involvement of the MAPK/ERK pathway effector ELK1 in the pathogenesis of autism caused by CHD8 mutations.
2019-11-27 | GSE141085 | GEO
Project description:The androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC), and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent (including constitutively active AR splice variants) mechanisms highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA2 as a regulator of AR signaling and a novel therapeutic target in PC. We demonstrate that GATA2 directly promotes AR expression (both full-length and splice variant), resulting in a strong positive correlation between GATA2 and AR expression in PC (cell lines and patient specimens). Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of AR (both full-length and splice variant). GATA2 co-localizes with AR and FOXA1 on chromatin to enhance recruitment of steroid receptor coactivators (SRCs) and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted for worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of AR (both full-length and splice variant) and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a “first-in-field” approach to target AR expression and function and improve outcomes in CRPC.
2015-01-21 | GSE63539 | GEO
Project description:Dual-color transcriptional profiling of siRNA-transfected cells, targeting ELK1 and NFYA, versus mock-transfected cells.
2009-11-04 | GSE18849 | GEO