Characterization of chromatin accessibility in metastatic prostate cancer
Ontology highlight
ABSTRACT:
PROVIDER: EGAS00001006698 | EGA |
REPOSITORIES: EGA
Similar Datasets
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
Project description:The few available therapies for mCRPC patients include taxanes docetaxel (DTX) and cabazitaxel (CBZ). However, development of resistance limits their clinical use. PCa that relapses after hormonal therapies, referred to as castration resistant prostate cancer (CRPC), often presents with metastases (mCRPC) that are the major cause of mortality. The few available therapies for mCRPC patients include taxanes docetaxel (DTX) and cabazitaxel (CBZ). However, development of resistance limits their clinical use. To study taxanes resistance, we produced CBZ resistant C4-2B cells (RC4-2B) and documented resistance to both CBZ and DTX in cell culture and in 3D prostaspheres settings. RNAseq identified increased expression of ABCB1 in RC4-2B, that was confirmed by immunoblotting and immunofluorescent analysis. ABCB1-specific inhibitor elacridar reversed CBZ and DTX resistance in RC4-2B cells, confirming ABCB1-mediated resistance mechanism.
2024-08-08 | GSE271075 | GEO
Project description:The androgen receptor (AR) pathway regulates key cell survival programs in prostate epithelium. Targeting the AR has a remarkable therapeutic index and represents a near-universal driver and therapeutic vulnerability in metastatic prostate cancer. Though most approaches directed toward the AR focus on inhibiting AR signaling, laboratory and now clinical data have shown that high dose, supraphysiological androgen treatment (SPA), results in growth repression and improved out-comes in subsets of prostate cancer patients. However, the mechanism(s) contributing to SPA re-sponse and resistance remain unclear. To characterize SPA signaling, we integrated metrics of gene expression changes induced by SPA together with cistrome data and protein-interactomes. These analyses determined that the Dimerization partner, RB-like, E2F and Multi-vulval class B (DREAM) complex mediates growth repression and downregulation of E2F targets in response to SPA. Notably, prostate cancers with complete genomic loss of RB1 responded to SPA treatment whereas loss of DREAM complex components such as RBL1/2 promoted resistance. Overexpres-sion of MYC resulted in complete resistance to SPA and attenuated the SPA/AR-mediated repres-sion of E2F target genes. These findings support a model of SPA-mediated growth repression that relies on the negative regulation of MYC by AR leading to repression of E2F1 signaling via the DREAM-SIN3A-HDAC complex. As RB1 and DREAM complex stability are regulated by MYC, a key determinant of tumor sensitivity to SPA, treatment may hinge on effectively repress-ing MYC activity. The integrity of MYC signaling and DREAM complex assembly may conse-quently serve as determinants of SPA responses and as pathways mediating SPA resistance.
2023-05-26 | GSE228896 | GEO
Project description:The androgen receptor (AR) pathway regulates key cell survival programs in prostate epithelium. Targeting the AR has a remarkable therapeutic index and represents a near-universal driver and therapeutic vulnerability in metastatic prostate cancer. Though most approaches directed toward the AR focus on inhibiting AR signaling, laboratory and now clinical data have shown that high dose, supraphysiological androgen treatment (SPA), results in growth repression and improved out-comes in subsets of prostate cancer patients. However, the mechanism(s) contributing to SPA re-sponse and resistance remain unclear. To characterize SPA signaling, we integrated metrics of gene expression changes induced by SPA together with cistrome data and protein-interactomes. These analyses determined that the Dimerization partner, RB-like, E2F and Multi-vulval class B (DREAM) complex mediates growth repression and downregulation of E2F targets in response to SPA. Notably, prostate cancers with complete genomic loss of RB1 responded to SPA treatment whereas loss of DREAM complex components such as RBL1/2 promoted resistance. Overexpres-sion of MYC resulted in complete resistance to SPA and attenuated the SPA/AR-mediated repres-sion of E2F target genes. These findings support a model of SPA-mediated growth repression that relies on the negative regulation of MYC by AR leading to repression of E2F1 signaling via the DREAM-SIN3A-HDAC complex. As RB1 and DREAM complex stability are regulated by MYC, a key determinant of tumor sensitivity to SPA, treatment may hinge on effectively repress-ing MYC activity. The integrity of MYC signaling and DREAM complex assembly may conse-quently serve as determinants of SPA responses and as pathways mediating SPA resistance.
2023-05-26 | GSE228895 | GEO
Project description:The androgen receptor (AR) pathway regulates key cell survival programs in prostate epithelium. Targeting the AR has a remarkable therapeutic index and represents a near-universal driver and therapeutic vulnerability in metastatic prostate cancer. Though most approaches directed toward the AR focus on inhibiting AR signaling, laboratory and now clinical data have shown that high dose, supraphysiological androgen treatment (SPA), results in growth repression and improved outcomes in subsets of prostate cancer patients. However, the mechanism(s) contributing to SPA response and resistance remain unclear. To characterize SPA signaling, we integrated metrics of gene expression changes induced by SPA together with cistrome data and protein-interactomes. These analyses determined that the Dimerization partner, RB-like, E2F and Multi-vulval class B (DREAM) complex mediates growth repression and downregulation of E2F targets in response to SPA. Notably, prostate cancers with complete genomic loss of RB1 responded to SPA treat-ment whereas loss of DREAM complex components such as RBL1/2 promoted resistance. Over-expression of MYC resulted in complete resistance to SPA and attenuated the SPA/AR-mediated repression of E2F target genes. These findings support a model of SPA-mediated growth repression that relies on the negative regulation of MYC by AR leading to repression of E2F1 signaling via the DREAM-SIN3A-HDAC complex. As RB1 and DREAM complex stabil-ity are regulated by MYC, a key determinant of tumor sensitivity to SPA, treatment may hinge on effectively repressing MYC activity. The integrity of MYC signaling and DREAM complex assembly may consequently serve as determinants of SPA responses and as pathways mediating SPA resistance.
2023-05-26 | GSE225481 | GEO
Project description:Mutations in the DREAM complex induce germline-like gene expression patterns including the increase of multiple mechanisms of DNA repair in the soma of Caenorhabditis elegans. This confers mutants of the DREAM complex resistance to a wide range of DNA damage types during development and aging.
2023-01-31 | PXD033836 | Pride
Project description:Enzalutamide (ENZA) is a frequently used therapy in metastatic castration-resistant prostate cancer (mCRPC). Baseline or acquired resistance to ENZA have been observed, but the molecular mechanisms of resistance are poorly understood. We aimed to identify proteins involved in ENZA resistance and to find therapy-predictive serum markers. We performed comparative proteome analyses on ENZA-sensitive parental (LAPC4, DUCAP) and -resistant prostate cancer cell lines (LAPC4-ENZA, DUCAP-ENZA) using liquid chromatography tandem mass spectrometry (LC-MS/MS). The most promising 4 marker candidates were selected using bioinformatic approaches. Serum concentrations of selected markers (ALCAM, AGR2, NDRG1, IDH1) were measured in 72 ENZA-treated mCRPC patients’ samples using ELISA. In addition, ALCAM serum levels were measured in 101 Abiraterone (ABI) and 100 Docetaxel (DOC)-treated mCRPC patients. Results were correlated with clinical and follow-up data. The functional role of ALCAM in ENZA resistance was assessed in vitro using siRNA. Our proteome analyses revealed 731 significantly differentially abundant proteins between ENZA-sensitive and -resistant cells and our filtering methods identified 4 biomarker candidates. Serum analyses of these proteins revealed only ALCAM to be associated with poor patient survival. Furthermore, higher baseline ALCAM levels were associated with poor survival in ABI- but not in DOC-treated patients. In LAPC4-ENZA resistant cells, ALCAM silencing by siRNA knockdown resulted in significantly enhanced ENZA sensitivity. Our analyses revealed that ALCAM serum levels may help to identify ENZA- and ABI-resistant patients and may thereby help to optimize future clinical decision-making. Our functional analyses suggest the possible involvement of ALCAM in ENZA resistance.
2022-06-24 | PXD031847 | Pride
Project description:Neuroendocrine (NE) differentiation in metastatic castration-resistant prostate cancer (mCRPC) usually develops through cellular plasticity. We recently characterized two mCRPC phenotypes with NE features; Androgen receptor (AR)-positive, NE-positive amphicrine prostate cancer (AMPC) and AR-negative small cell or neuroendocrine prostate cancer (SCNPC). Here, we interrogate the RE-1 silencing transcription factor (REST) pathway in mCRPC and demonstrate that SRRM3 has analogous functions to SRRM4 and mediates NE differentiation through alternative splicing of REST. We scrutinize transcriptome datasets across species and tumor types and discover that SRRM3 and SRRM4 expression define molecular phenotypes in AMPC and SCNPC. Notably, we characterize two AMPC phenotypes driven by either REST attenuation or ASCL1 activity and three SCNPC phenotypes with progressive activation of neuronal transcription factor programs. Together, our data provides a biological framework for classifying NE phenotypes in mCRPC that could be useful for future therapeutic development and precision medicine applications.
2021-07-14 | GSE158598 | GEO