Molecular determinants of response to high dose androgen therapy in prostate cancer
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ABSTRACT:
PROVIDER: PRJNA560394 | ENA |
REPOSITORIES: ENA
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Project description:Clinical trials of high-dose androgen therapy for prostate cancer have shown promising efficacy but are limited by lack of criteria to identify likely responders. To elucidate factors that govern the growth-repressive effects of high-dose androgens we applied an unbiased integrative approach utilizing genetic screens and transcriptional profiling of prostate cancer cells with or without demonstrated phenotypic sensitivity to androgen-mediated growth repression. Through this comprehensive analysis, we identified genetic events and related signaling networks that determine the response to both high-dose androgen and androgen withdrawal. We applied these findings to develop a gene signature that may serve as an early indicator of treatment response and identify men with tumors amenable to high dose androgen therapy.
2019-12-02 | GSE135879 | GEO
Project description:Clinical trials of high-dose androgen (HDA) therapy for prostate cancer (PC) have shown promising efficacy but are limited by lack of criteria to identify likely responders. To elucidate factors that govern the growth-repressive effects of HDAs, we applied an unbiased integrative approach using genetic screens and transcriptional profiling of PC cells with or without demonstrated phenotypic sensitivity to androgen-mediated growth repression. Through this comprehensive analysis, we identified genetic events and related signaling networks that determine the response to both HDA and androgen withdrawal. We applied these findings to develop a gene signature that may serve as an early indicator of treatment response and identify men with tumors that are amenable to HDA therapy.
| S-EPMC6795499 | biostudies-literature
Project description:Enzalutamide, a second-generation androgen receptor (AR) antagonist, has demonstrated clinical benefit in men with prostate cancer. However, it only provides a temporary response and modest increase in survival, indicating a rapid evolution of resistance. Previous studies suggest that enzalutamide may function as a partial transcriptional agonist, but the underlying mechanisms for enzalutamide-induced transcription remain poorly understood. Here, we show that enzalutamide stimulates expression of a novel subset of genes distinct from androgen-responsive genes. Treatment of prostate cancer cells with enzalutamide enhances recruitment of pioneer factor GATA2, AR, Mediator subunits MED1 and MED14, and RNA Pol II to regulatory elements of enzalutamide-responsive genes. Mechanistically, GATA2 functions in directing AR, Mediator and Pol II loading to enzalutamide-responsive gene loci. Importantly, the GATA2 inhibitor K7174 inhibits enzalutamide-induced transcription by decreasing binding of the GATA2/AR/Mediator/Pol II transcriptional complex, contributing to sensitization of prostate cancer cells to enzalutamide treatment. Our findings provide mechanistic insight into the future combination of GATA2 inhibitors and enzalutamide for improved AR-targeted therapy.
2019-09-03 | GSE125014 | GEO
Project description:Androgen Deprivation Therapy Potentiates the Efficacy of Vascular Targeted Photodynamic Therapy of Prostate Cancer Xenografts
| PRJNA431647 | ENA
Project description:Hypoxia inducible factor 1 (HIF1) has been shown to cooperate with the androgen receptor (AR) in activation of oncogenic pathways in prostate cancer (PCa). Here we hypothesized that HIF1 also plays a role in PCa response to androgen deprivation therapy (ADT). Comparison of gene expression profiles of androgen exposed (AE) and androgen deprived (AD) CWR22 PCa xenografts identified 596 upregulated and 748 downregulated genes after ADT. Gene ontology (GO) analysis of the differentially expressed genes showed significant enrichment of the biological processes cell proliferation, cell cycle and metabolism and suggested suppression of these processes after ADT. A set of 80 hypoxia-inducible genes were identified in 22Rv1 and LNCaP cell lines treated with hypoxia and showed considerable overlap (53%) with the downregulated genes. Immunostaining of the hypoxia marker pimonidazole showed no difference between AE- and AD-tumors. Comparison of the differentially expressed genes with lists of 1115 direct AR- and 276 direct HIF1-target genes identified 138 AR- and 40 HIF1-targets that were regulated after ADT, including six shared AR- and HIF1-targets for which downregulation was confirmed with RT-PCR. Most HIF1-targets were downregulated and included in the significant biological processes and the set of hypoxia-inducible genes. The downregulation of HIF1-targets was consistent with decreased HIF1A immunostaining in AD- compared to AE-tumors (p=0.002). A decrease in HIF1A immunostaining after ADT was also demonstrated in a cohort of 35 PCa patients (p<0.001). These data suggest suppressed HIF1-signaling after ADT and a shared role of HIF1 and AR in the regressive phase of PCa after ADT. Prostate cancer xenografts were subjected to adrogen deprivation therapy and analysed with regard to changes in gene expressions. Cell culture experiments were performed to generate prostate cancer specific gene lists associated with hypoxia.
2013-10-02 | E-GEOD-42868 | biostudies-arrayexpress
Project description:Testosterone is the canonical growth factor of prostate cancer but can paradoxically suppress its growth when present at supraphysiological levels. We have previously demonstrated that the cyclical administration of supraphysiological androgen (SPA), entitled Bipolar Androgen Therapy (BAT), can result in tumor regression and clinical benefit for patients with castration-resistant prostate cancer. However, predictors and mechanisms of response and resistance have been ill-defined. Here we show that growth inhibition of prostate cancer models by SPA requires high androgen receptor (AR) activity and is driven in part by downregulation of MYC. Using matched sequential patient biopsies, we show that high pre-treatment AR activity predicts downregulation of MYC, clinical response, and prolonged progression-free and overall survival for patients on BAT. BAT induced strong downregulation of AR in all patients, which is shown to be a primary mechanism of acquired resistance to SPA. Acquired resistance can be overcome by alternating SPA with the AR inhibitor enzalutamide, which induces adaptive upregulation of AR and re-sensitizes prostate cancer to SPA. This work identifies high AR activity score as a predictive biomarker of response to BAT and supports a new treatment paradigm for prostate cancer involving alternating between AR inhibition and activation
2022-11-01 | GSE213443 | GEO
Project description:Testosterone is the canonical growth factor of prostate cancer but can paradoxically suppress its growth when present at supraphysiological levels. We have previously demonstrated that the cyclical administration of supraphysiological androgen (SPA), entitled Bipolar Androgen Therapy (BAT), can result in tumor regression and clinical benefit for patients with castration-resistant prostate cancer. However, predictors and mechanisms of response and resistance have been ill-defined. Here we show that growth inhibition of prostate cancer models by SPA requires high androgen receptor (AR) activity and is driven in part by downregulation of MYC. Using matched sequential patient biopsies, we show that high pre-treatment AR activity predicts downregulation of MYC, clinical response, and prolonged progression-free and overall survival for patients on BAT. BAT induced strong downregulation of AR in all patients, which is shown to be a primary mechanism of acquired resistance to SPA. Acquired resistance can be overcome by alternating SPA with the AR inhibitor enzalutamide, which induces adaptive upregulation of AR and re-sensitizes prostate cancer to SPA. This work identifies high AR activity score as a predictive biomarker of response to BAT and supports a new treatment paradigm for prostate cancer involving alternating between AR inhibition and activation
2022-11-01 | GSE213437 | GEO
Project description:Testosterone is the canonical growth factor of prostate cancer but can paradoxically suppress its growth when present at supraphysiological levels. We have previously demonstrated that the cyclical administration of supraphysiological androgen (SPA), entitled Bipolar Androgen Therapy (BAT), can result in tumor regression and clinical benefit for patients with castration-resistant prostate cancer. However, predictors and mechanisms of response and resistance have been ill-defined. Here we show that growth inhibition of prostate cancer models by SPA requires high androgen receptor (AR) activity and is driven in part by downregulation of MYC. Using matched sequential patient biopsies, we show that high pre-treatment AR activity predicts downregulation of MYC, clinical response, and prolonged progression-free and overall survival for patients on BAT. BAT induced strong downregulation of AR in all patients, which is shown to be a primary mechanism of acquired resistance to SPA. Acquired resistance can be overcome by alternating SPA with the AR inhibitor enzalutamide, which induces adaptive upregulation of AR and re-sensitizes prostate cancer to SPA. This work identifies high AR activity score as a predictive biomarker of response to BAT and supports a new treatment paradigm for prostate cancer involving alternating between AR inhibition and activation
2023-04-12 | GSE229555 | GEO
Project description:Prostate epithelial cells depend on androgens for survival and function. In early prostate cancer, besides survival, androgens also regulated tumor growth, which is exploited by androgen ablation/ blockade therapies in metastatic disease. The aim of the present study was to characterize the role of the androgen receptor pathway in prostate cancer progression and to identify potential disease markers. Microarray analysis was used to establish the androgen-regulated gene expression profile, upon stimulation with the synthetic androgen R1881 or the antiandrogen hydroxyflutamide, of the androgen-responsive PC346C cell line and its derivative castration-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A mutated AR) PC346C, PC346DCC, PC346Flu1 and PC346Flu2 were stimulated with 1 nM R1881, 1uM hydroxyflutamide or vehicle control, following a 4, 8 and 16h time-course. Each condition was performed in dye-swap, using biological duplicates. PC346DCC was only stimulated with R1881, not hydroxyflutamide.
2011-08-04 | E-GEOD-22914 | biostudies-arrayexpress
Project description:Androgen ablation therapy (AAT) is standard treatment for locally-advanced/metastatic prostate cancer (PCa). Many patients develop castration-resistance (CRPCa) after ~2-3 years, with a poor prognosis. The molecular mechanisms underlying CRPCa progression are unclear. mRNA-Seq was performed on tumours from 7 patients with locally-advanced/metastatic PCa before and ~22 weeks after AAT initiation. Differentially regulated genes were identified in treatment pairs. Tumour biopsies from 7 patients were taken before and after AAT treatment
2013-10-07 | E-GEOD-48403 | biostudies-arrayexpress