The effect of androgen deprivation on human prostate xenograft tumor LuCaP35
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE33316 | GEO | 2011/12/06
SECONDARY ACCESSION(S): PRJNA149301
REPOSITORIES: GEO
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Project description:Androgen deprivation is a standard of care front-line therapy for human prostate cancer, however, majority of patients will eventally develop resistance to androgen deprivation. In this study, using a human prostate cancer xenograft model -LuCaP35, we examiend the gene expression changes after castration. We compare the gene expression of 5 LuCaP35 xenografts from non-treated mice (Control), and 5 androgen-deprived LuCaP35 xenografts from castrated mice (Castration).
2011-12-06 | E-GEOD-33316 | biostudies-arrayexpress
Project description:Androgens are required for prostate development, growth and physiology, by activating the androgen receptor (AR) upon activation by testosterone and dihydrotestosterone (DHT), the AR undergoes conformational changes, dimerizes and translocates to the cell nucleus regulation important genes releted to cell survival. Understanding the mechanisms of androgen regulation in the prostate gland is important, because the prostate is affected by several different diseases, in particular prostate cancer (PCa). Several ways exist to treat prostate cancer and promote epithelial cell death. Treatments involving androgen manipulation include surgical castration (bilateral orchiectomy), antiandrogens (usually AR antagonists), or substances that inhibit androgen synthesis (5 alpha-reductase inhibitors, gonadotrophin-releasing hormone blockers). 17 beta-estradiol exerts anti-androgen effects by blocking the hypothalamic production of gonadotropin-releasing hormone and thereby inhibiting the production of testosterone by the testes , but also acts locally via interactions with either of the estrogen receptors found in the gland. It is known that the kinetics of apoptosis are different in the rat ventral prostate (VP) of castrated rats (Cas group) and in rats subjected to 17 beta-estradiol high dose (group E2) or their combination (group Cas+E2), with an evident additive effect in the latter situation (Garcia-Florez et al, 2005). The microarray approach was done to figure out what genes are expressed and how the cells of ventral prostate gland responses when the androgen is not available comparing three diferent androgen deprivation methods (sirurgical castration, high dose of 17-beta estradiol and both treatment combined).
2015-03-28 | GSE56289 | GEO
Project description:Androgens are required for prostate development, growth and physiology, by activating the androgen receptor (AR) upon activation by testosterone and dihydrotestosterone (DHT), the AR undergoes conformational changes, dimerizes and translocates to the cell nucleus regulation important genes releted to cell survival. Understanding the mechanisms of androgen regulation in the prostate gland is important, because the prostate is affected by several different diseases, in particular prostate cancer (PCa). Several ways exist to treat prostate cancer and promote epithelial cell death. Treatments involving androgen manipulation include surgical castration (bilateral orchiectomy), antiandrogens (usually AR antagonists), or substances that inhibit androgen synthesis (5 alpha-reductase inhibitors, gonadotrophin-releasing hormone blockers). 17 beta-estradiol exerts anti-androgen effects by blocking the hypothalamic production of gonadotropin-releasing hormone and thereby inhibiting the production of testosterone by the testes , but also acts locally via interactions with either of the estrogen receptors found in the gland. It is known that the kinetics of apoptosis are different in the rat ventral prostate (VP) of castrated rats (Cas group) and in rats subjected to 17 beta-estradiol high dose (group E2) or their combination (group Cas+E2), with an evident additive effect in the latter situation (Garcia-Florez et al, 2005). The microarray approach was done to figure out what genes are expressed and how the cells of ventral prostate gland responses when the androgen is not available comparing three diferent androgen deprivation methods (sirurgical castration, high dose of 17-beta estradiol and both treatment combined). Forty-eight 21-day-old male Wistar rats were obtained from the Multidisciplinary Center for Biological Research (CEMIB), University of Campinas. The animals were kept under normal light conditions (12-h light:dark cycle) and received filtered tap water and Purina rodent chow ad libitum. On the 90th day after birth, the rats were divided in four groups (n=3) and assigned to different treatment groups. To cause androgen deprivation, we utilized three different procedures with different effects on epithelial cell apoptosis. Animals in the first group were castrated (Cas) by orchiectomy via scrotal incision under ketamine (150 mg/Kg body weight) and xylazin (10 mg/kg body weight) anesthesia. Animals in the second group received a 25 mg/Kg body weight dose of 17β-estradiol diluted in corn oil (E2 group). The third group received a combination of both treatments (Cas+E2 group) (combined orchiectomy and 17β-estradiol). In the control group (Ct; normal androgen and estrogen), the animals received only the vehicle. Three days after the treatments, the rats were killed by anesthetic overdose, and the ventral prostate was dissected out for the microarray and immunohistochemistry analyses.
2015-03-28 | E-GEOD-56289 | biostudies-arrayexpress
Project description:Following androgen ablation therapy (AAT), the vast majority of prostate cancer patients develop treatment resistance with a median time of 18-24 months to disease progression. To identify molecular targets that aid in prostate cancer cell survival and contribute to the androgen independent phenotype, we evaluated changes in LNCaP cell gene expression during 12 months of androgen deprivation. At time points reflecting critical growth and phenotypic changes, we performed Affymetrix expression array analysis to examine the effects of androgen deprivation during the acute response, during the period of apparent quiescence, and during the emergence of highly proliferative, androgen-independent prostate cancer cells (LNCaP-AI). We discovered alterations in gene expression for a host of molecules associated with promoting prostate cancer cell growth and survival, regulating cell cycle progression, apoptosis and adrenal androgen metabolism, in addition to AR co-regulators and markers of neuroendocrine disease. These findings illustrate the complexity and unpredictable nature of cancer cell biology and contribute greatly to our understanding of how prostate cancer cells likely survive AAT. The value of this longitudinal approach lies in the ability to examine gene expression changes throughout the cellular response to androgen deprivation; it provides a more dynamic illustration of those genes which contribute to disease progression in addition to specific genes which constitute a malignant androgen-independent phenotype. In conclusion, it is of great importance that we employ new approaches, such as the one proposed here, to continue exploring the cellular mechanisms of therapy resistance and identify promising targets to improve cancer therapeutics. Experiment Overall Design: To identify molecular targets that aid in prostate cancer cell survival and contribute to the androgen independent phenotype, we evaluated changes in LNCaP cell gene expression during 12 months of androgen deprivation. At time points reflecting critical growth and phenotypic changes, we performed Affymetrix expression array analysis to examine the effects of androgen deprivation during the acute response, during the period of apparent quiescence, and during the emergence of highly proliferative, androgen-independent prostate cancer cells (LNCaP-AI).
2008-04-07 | E-GEOD-8702 | biostudies-arrayexpress
Project description:The androgen receptor (AR) is a ligand-inducible transcription factor that mediates androgen action in target tissues. Upon ligand binding, the AR binds to thousands of genomic loci and activates a cell-type specific gene program. Prostate cancer growth and progression depend on androgen-induced AR signalling. Treatment of advanced prostate cancer through medical or surgical castration leads to initial response and durable remission, but resistance inevitably develops. In castration-resistant prostate cancer (CRPC), AR activity remains critical for tumor growth despite androgen deprivation. While previous studies have focused on ligand-dependent AR signalling, in this study we explore AR function under the androgen-deprived conditions characteristic of CRPC. Our data demonstrate that the AR persistently occupies a distinct set of genomic loci after androgen deprivation in CRPC. These androgen-independent AR occupied regions have constitutively open chromatin structures that lack the canonical androgen response element and are independent of FoxA1, a transcription factor involved in ligand-dependent AR targeting. Many AR binding events occur at proximal promoters, which can act as enhancers to augment transcriptional activities of other promoters through DNA looping. We further show that androgen-independent AR binding directs a distinct gene expression program in CRPC, which is necessary for the growth of CRPC after androgen withdrawal. LNCaP, C4-2B, or 22RV1 cells were cultured in hormone-free media for 3 days and then treated with ethanol vehicle or DHT (10nM) for 4h or 16h prior to ChIP-seq or RNA-seq assays. For siRNA transfection, cells were transfected with AR siRNA or control siRNA for 3 days prior to RNA-seq assays.
2012-10-02 | E-GEOD-40050 | biostudies-arrayexpress
Project description:The androgen receptor (AR) is a ligand-inducible transcription factor that mediates androgen action in target tissues. Upon ligand binding, the AR binds to thousands of genomic loci and activates a cell-type specific gene program. Prostate cancer growth and progression depend on androgen-induced AR signalling. Treatment of advanced prostate cancer through medical or surgical castration leads to initial response and durable remission, but resistance inevitably develops. In castration-resistant prostate cancer (CRPC), AR activity remains critical for tumor growth despite androgen deprivation. While previous studies have focused on ligand-dependent AR signalling, in this study we explore AR function under the androgen-deprived conditions characteristic of CRPC. Our data demonstrate that the AR persistently occupies a distinct set of genomic loci after androgen deprivation in CRPC. These androgen-independent AR occupied regions have constitutively open chromatin structures that lack the canonical androgen response element and are independent of FoxA1, a transcription factor involved in ligand-dependent AR targeting. Many AR binding events occur at proximal promoters, which can act as enhancers to augment transcriptional activities of other promoters through DNA looping. We further show that androgen-independent AR binding directs a distinct gene expression program in CRPC, which is necessary for the growth of CRPC after androgen withdrawal.
2012-10-02 | GSE40050 | GEO
Project description:The androgen receptor (AR) is the dominant growth factor in prostate cancer. Understanding how it regulates the human transcriptome is of paramount importance. The early effects of castration on human prostate cancer have not previously been studied. In this study 27 patients were medically castrated with degarelix seven days before radical prostatectomy. Resected tumour was compared with matched controlled untreated prostate cancer tissue by means of mass spectrometry, immunohistochemistry and gene expression array (validated by RT-PCR). All patients had castrate levels of serum androgen with reduced levels of intra-prostatic androgen at prostatectomy. Differential expression of known androgen regulated genes (TMPRSS2, KLK3, CAMKK2, FKBP5) was observed. We identified 749 genes downregulated and 908 genes upregulated following castration. AR regulation of AMACR expression and three other genes (FAM129A, RAB27A and KIAA0101) was confirmed. Up-regulation of oestrogen receptor alpha (ESR1) expression was observed in malignant epithelia. This was associated with differential expression of ESR1 regulated genes and correlated with proliferation (Ki67 expression).
2015-10-16 | GSE72920 | GEO
Project description:Inhibition of androgen-receptor (AR)signaling is the foundation of therapeutic regimens for advanced prostate cancers. However, nearly all patientsdevelop resistance and some never respond. To identify genes that mediate resistance to androgen ablation therapy, we performed an open reading frame (ORF) expression screen of17,255 ORFs and found that the transcription factorCREB5robustly conferred resistance to androgen deprivation and AR inhibition by enzalutamide. CREB5 overexpressionincreased enzalutamide-resistance 45-fold, enhanced resistance of tumor xenografts. CREB5 expression was also essential for enzalutamide-resistance patient-derived organoids. In clinical mCRPC, CREB5is frequently amplified and itsoverexpression positively correlated with castration resistance gene signatures including those of MYC and cell cycle. Mechanistically, CREB5 directly interacted at AR binding sites andenhanced site-specific AR bindingin enzalutamide. This dysregulated expression of 393 AR target genes including MYC and CDK1.These observations identifyCREB5asadriver of enzalutamide-resistance in a subset of advancedprostate cancer.
2019-09-21 | GSE137775 | GEO
Project description:Androgen deprivation therapy (ADT) is a foundational treatment for advanced prostate cancer, but more than half of patients treated with ADT experience debilitating cognitive impairments in domains known to be mediated by the hippocampus and prefrontal cortex. Unfortunately, there are few treatments to prevent or reverse these changes from occuring, thus severely decreasing quality of life in patients. To begin studying these deficits, surgically castrated rats were used to model cognitive impairments associated with the spatial learning and executive function, then chronically treated with the multimodal antidepressant, vortioxetine, as in intervention to reverse these impairments. Vortioxetine effectively rescued cognitive deficits in after surgical castration, and increased resposivity in in vivo evoked local field potentials within the Schaeffer Collateral-CA1 pathway and the ventral hippocampus-mPFC pathway. Surgical castration also induced significant changes in gene expression within the mPFC and the dorsal hippcampus, whereas vortioxetine had little effect. Pathway analysis revealed that androgen depletion altered pathways related to synaptic plasticity. These results suggest that these two regions may be vulnerable to ADT, contributing to cognitive impairment in prostate cancer patients. Further, vortioxetine may be a candidate to improve cognition in patients that experience cognitive decline after androgen deprivation therapy for prostate cancer and may do so by restoring molecular and circuit level plasticity-related mechanisms compromised by ADT.
2023-10-04 | GSE236207 | GEO
Project description:To identify molecular singnal alterations between androgen dependent prostate cancer and castration resistant prostate cancer, we performed interspecies comparative microarray analyses using RNAs prepared from uncastrasion and castration tumor from LNCAP Orhotopic xenograft models of prostate cancer. microarray data from uncastrasion and castration tumor revealed that the gene expression profile is most significantly altered in between androgen dependent prostate cancer and castration resistant prostate cancer. Comparative analyses of LNCAP Orhotopic xenograft models of prostate cancer showed that genes involved in androgen dependent and androgen independent tumor were significantly altered.
2013-04-20 | GSE46218 | GEO