Androgen and Glucocorticoid stimulation of LREX' cells in vitro
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE51871 | GEO | 2013/12/27
SECONDARY ACCESSION(S): PRJNA225673
REPOSITORIES: GEO
Similar Datasets
Project description:The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Using the LnCaP/AR xenograft model, we identified induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors. From a resistant xenograft tumor, we derived a GR expressing resistant subline called LREX. In this model, activation of GR and AR activate a similar but distinguishable set of target genes. LREX' cells were cultured in steroid depleted media and then treated for 8 hours with the indicated drugs in biological triplicates.
2013-12-27 | E-GEOD-51871 | biostudies-arrayexpress
Project description:The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Using the LnCaP/AR xenograft model, we identified induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors. From a resistant xenograft tumor, we derived a GR expressing resistant subline called LREX' which maintains the resistant phenotype. mRNA expression was used to characterize resistant tissues. LnCaP/AR cells were injected into castrate mice and tumors were established. Mice were then treated with vehicle (Con), 4 days of anti-androgen (ARN-509 10mgkg), or were maintained on anti-androgen (10mg/kg ARN-509 or enzalutamide) until emergence of resistance. Resistant tissues continued to be exposed to anti-androgen through time of harvest. LREX' (LnCaP/AR Resistant to Enzalutamide Xenograft Derived) was derived from an enzalutamide resistant xenograft and was re-injected into castrate mice undergoing continual treatment with enzalutamide. The GR probe on the Illumina array failed to detect GR expression. Therefore, GR expression as determined by qPCR is annotated separately. Of the 10 control tissues, 8 were analyzed twice (technical duplicates annotated as A and B).
2013-12-27 | E-GEOD-51873 | biostudies-arrayexpress
Project description:The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Using the LnCaP/AR xenograft model, we identified induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors. From a resistant xenograft tumor, we derived a GR expressing resistant subline called LREX' which maintains the resistant phenotype. mRNA expression was used to characterize resistant tissues.
2013-12-27 | GSE51873 | GEO
Project description:Molecular mechanisms underlying resistance to androgen deprivation therapy (ADT) and, in particular, to antiandrogen Enzalutamide, in treating castration-resistant prostate cancer (CRPC), remain incompletely understood. Through screening >120 CRPC patient samples, we observed 3 expression patterns of androgen receptor (AR) protein: primarily nuclear (nuc-AR), mixed nuclear/cytoplasmic expression (nuc/cyto-AR), and low/no expression (AR-/lo). Xenograft CRPC modeling in 4 models (i.e., LNCaP, VCaP, LAPC4, and LAPC9) recapitulated the 3 AR expression patterns in castration-resistant tumors developed from parental androgen-dependent tumors. Strikingly, although the 3 CRPC models that retained AR expression (LNCaP, VCaP, and LAPC4) responded, to different levels and in different kinetics, to Enzalutamide, the AR-/lo LAPC9 CRPC was completely refractory to Enzalutamide. By combining whole-genome RNA-Seq and biochemical analyses together with experimental combinatorial therapy in the LNCaP and LAPC9 models, we identified BCL-2 as a critical therapeutic target in both AR+/hi and AR-/lo, Enzalutamide-resistant CRPC models.
2018-08-01 | GSE88752 | GEO
Project description:LREX' are a LnCAP/AR subline with natural expresison of the glucocorticoid receptor. We used the model to compare the AR and GR cistromes in prostate tissue.
2013-12-27 | GSE51497 | GEO
Project description:LREX' are a LnCAP/AR subline with natural expresison of the glucocorticoid receptor. We used the model to compare the AR and GR cistromes in prostate tissue. We determined the GR cistrone in the presence of Dex (100nM) treatment and the AR cistrome in the presene of DHT (1nM) treatment.
2013-12-27 | E-GEOD-51497 | biostudies-arrayexpress
Project description:In prostate cancer, resistance to the antiandrogen enzalutamide (Enz) can occur through bypass of androgen receptor (AR) blockade by the glucocorticoid receptor (GR). In contrast to fixed genomic alterations, here we show that GR-mediated antiandrogen resistance is adaptive and reversible due to regulation of GR expression by a tissue-specific enhancer. GR expression is silenced in prostate cancer by a combination of AR binding and EZH2-mediated repression at the GR locus, but is restored in advanced prostate cancers upon reversion of both repressive signals. Remarkably, BET bromodomain inhibition resensitizes drug-resistant tumors to Enz by selectively impairing the GR signaling axis via this enhancer. In addition to revealing an underlying molecular mechanism of GR-driven drug resistance, these data suggest that inhibitors of broadly active chromatin-readers could have utility in nuanced clinical contexts of acquired drug resistance with a more favorable therapeutic index.
2017-09-11 | GSE103449 | GEO
Project description:Next generation androgen receptor (AR) signaling inhibitors have significantly improved the survival of men with metastatic castration-resistant prostate cancer (mCPRC) but resistance remains a problem. Genomic alterations at the AR locus are present in ~50% of mCRPC patients, typically in association with large numbers of copy number gains and losses across the genome. To explore the functional consequences of these copy number alterations, we screened an shRNA library targeting all genes deleted in prostate cancer (the prostate cancer deletome: 4380 shRNAs targeting 730 genes) for next generation antiandrogen resistance using a clinically-validated model of enzalutamide-sensitive, AR-driven mCRPC LNCaP/AR. The Chromatin helicase DNA-binding factor (CHD1) scored as a top candidate and was validated in vitro and in vivo using multiple independent shRNAs and CRISPR guides. Mechanistically, CHD1 loss led to global changes in open and closed chromatin (ATAC-seq) as well as downregulation of canonical AR target genes upon the challenge of antiandrogen, despite robust AR expression. Integrative analysis of ATAC- and RNA-seq changes following CHD1 deletion identified 23 candidate transcription factor drivers of enzalutamide resistance. CRISPR-based unbiased functional screening identified 4 of these drivers may drive the AR-independent resistance, including glucocorticoid receptor (GR), BRN2, NR2F1 and TBX2. Genetic studies further establish that CHD1 loss confers antiandrogen resistance by converting mCRPC cells from AR-dependence to GR-dependence in one of the resistant LNCaP/AR clone. Thus, CHD1 functions as a molecular tuner to regulate chromatin plasticity and maintain oncogenic AR signaling, as well as AR dependency.
2020-03-26 | GSE127957 | GEO
Project description:Next generation androgen receptor (AR) signaling inhibitors have significantly improved the survival of men with metastatic castration-resistant prostate cancer (mCPRC) but resistance remains a problem. Genomic alterations at the AR locus are present in ~50% of mCRPC patients, typically in association with large numbers of copy number gains and losses across the genome. To explore the functional consequences of these copy number alterations, we screened an shRNA library targeting all genes deleted in prostate cancer (the prostate cancer deletome: 4380 shRNAs targeting 730 genes) for next generation antiandrogen resistance using a clinically-validated model of enzalutamide-sensitive, AR-driven mCRPC LNCaP/AR. The Chromatin helicase DNA-binding factor (CHD1) scored as a top candidate and was validated in vitro and in vivo using multiple independent shRNAs and CRISPR guides. Mechanistically, CHD1 loss led to global changes in open and closed chromatin (ATAC-seq) as well as downregulation of canonical AR target genes upon the challenge of antiandrogen, despite robust AR expression. Integrative analysis of ATAC- and RNA-seq changes following CHD1 deletion identified 23 candidate transcription factor drivers of enzalutamide resistance. CRISPR-based unbiased functional screening identified 4 of these drivers may drive the AR-independent resistance, including glucocorticoid receptor (GR), BRN2, NR2F1 and TBX2. Genetic studies further establish that CHD1 loss confers antiandrogen resistance by converting mCRPC cells from AR-dependence to GR-dependence in one of the resistant LNCaP/AR clone. Thus, CHD1 functions as a molecular tuner to regulate chromatin plasticity and maintain oncogenic AR signaling, as well as AR dependency.
2020-03-26 | GSE127241 | GEO
Project description:Next generation androgen receptor (AR) signaling inhibitors have significantly improved the survival of men with metastatic castration-resistant prostate cancer (mCPRC) but resistance remains a problem. Genomic alterations at the AR locus are present in ~50% of mCRPC patients, typically in association with large numbers of copy number gains and losses across the genome. To explore the functional consequences of these copy number alterations, we screened an shRNA library targeting all genes deleted in prostate cancer (the prostate cancer deletome: 4380 shRNAs targeting 730 genes) for next generation antiandrogen resistance using a clinically-validated model of enzalutamide-sensitive, AR-driven mCRPC LNCaP/AR. The Chromatin helicase DNA-binding factor (CHD1) scored as a top candidate and was validated in vitro and in vivo using multiple independent shRNAs and CRISPR guides. Mechanistically, CHD1 loss led to global changes in open and closed chromatin (ATAC-seq) as well as downregulation of canonical AR target genes upon the challenge of antiandrogen, despite robust AR expression. Integrative analysis of ATAC- and RNA-seq changes following CHD1 deletion identified 23 candidate transcription factor drivers of enzalutamide resistance. CRISPR-based unbiased functional screening identified 4 of these drivers may drive the AR-independent resistance, including glucocorticoid receptor (GR), BRN2, NR2F1 and TBX2. Genetic studies further establish that CHD1 loss confers antiandrogen resistance by converting mCRPC cells from AR-dependence to GR-dependence in one of the resistant LNCaP/AR clone. Thus, CHD1 functions as a molecular tuner to regulate chromatin plasticity and maintain oncogenic AR signaling, as well as AR dependency.
2020-03-26 | GSE126917 | GEO