The androgen receptor plays a critical role throughout the progression of prostate cancer and is an important drug target for this disease. While chromatin immunoprecipitation coupled with massively parallel sequencing (ChIP-Seq) is becoming an essential tool in studying transcription and chromatin modification factors, it has rarely been employed in the context of drug discovery. Here we report the first publicly available genome-wide and dose-dependent inhibition landscape of AR binding by drug-like small molecules including correlation with binding strength using ChIP-Seq. Integration of sequence analysis, transcriptome profiling, cell viability assays and in vivo tumor inhibition studies enabled us to establish a direct cistrome-activity relationship for two novel potent AR antagonists. By selectively occupying the strongest binding sites, AR signaling remains active even when low androgen levels are low, a scenario characteristic of first-line androgen ablation therapy. Coupled cistrome and transcriptome profiling upon small molecule antagonism led to the identification of not only key direct downstream effectors of AR but also their mode of regulation: unbiased pathway mapping revealed that AR is a key modulator of steroid metabolism by forming a tightly controlled feedback loop with other nuclear receptor family members. Furthermore, we found AR has an extensive role in negative gene regulation and estrogen (related) receptor likely mediates its function as a transcriptional repressor. In conclusion, our study provides a global and dynamic view of ARs regulatory program upon antagonism, which may serve as a molecular basis for deciphering and developing AR therapeutics.
Dose-dependent effects of small-molecule antagonists on the genomic landscape of androgen receptor binding.
Treatment
View SamplesA large, prospective, non-interventional study was designed to study gene expression changes in peripheral blood mononuclear cells (PBMCs) associated with asthma exacerbations over the course of a year. PBMC samples were collected from subjects at the time of the study visits defined as 1) Quiet: during stable disease at 3 month intervals, 2) Exacerbation: during a 14 day period of deteriorating asthma and 3) Follow-up: within 14 days after cessation of an exacerbation. Gene expression levels during stable asthma, exacerbation, and two weeks after an exacerbation were compared.
Pathways activated during human asthma exacerbation as revealed by gene expression patterns in blood.
Specimen part, Race
View SamplesSchizophrenia is a complex psychiatric disorder encompassing a range of symptoms and etiology dependent upon the interaction of genetic and environmental factors. Several risk genes, such as DISC1, have been associated with schizophrenia as well as bipolar disorder (BPD) and major depressive disorder (MDD), consistent with the hypothesis that a shared genetic architecture could contribute to divergent clinical syndromes. The present study compared gene expression profiles across three brain regions in post-mortem tissue from matched subjects with schizophrenia, BPD or MDD and unaffected controls. Post-mortem brain tissue was collected from control subjects and well-matched subjects with schizophrenia, BPD, and MDD (n=19 from each group). RNA was isolated from hippocampus, Brodmann Area 46, and associative striatum and hybridized to U133_Plus2 Affymetrix chips. Data were normalized by RMA, subjected to pairwise comparison followed by Benjamini and Hochberg False Discovery Rate correction (FDR). Samples derived from patients with schizophrenia exhibited many more changes in gene expression across all brain regions than observed in BPD or MDD. Several genes showed changes in both schizophrenia and BPD, though the magnitude of change was usually larger in schizophrenia. Several genes that have variants associated with schizophrenia were found to have altered expression in multiple regions of brains from subjects with schizophrenia. Continued evaluation of circuit-level alterations in gene expression and gene-network relationships may further our understanding of how genetic variants may be influencing biological processes to contribute to psychiatric disease.
STEP levels are unchanged in pre-frontal cortex and associative striatum in post-mortem human brain samples from subjects with schizophrenia, bipolar disorder and major depressive disorder.
Sex, Age, Specimen part, Disease, Disease stage, Race
View SamplesThis series of samples comprises multiple early embryonic time courses for C. elegans. Time courses consisting of 10 time points each for 4 different genotypes are included: wild-type (strain N2 grown on E. coli strain OP50), pie-1(zu154) (progeny of homozygous mutant mothers [Unc] of strain JJ532 grown on E. coli strain OP50), pie-1(zu154);pal-1(RNAi) (progeny of homozygous mutant mothers [Unc] of strain JJ532 grown on E. coli strain HT115 expressing pal-1 hairpin RNA), and mex-3(zu155);skn-1(RNAi) (progeny of homozygous mutant mothers [Dpy] of strain JJ518 grown on E. coli strain HT115 expressing skn-1 hairpin RNA). Embryos were manually staged by morphology at the 4-cell stage and allowed to develop in water for defined amounts of time at 22 degrees C. RNA was amplified as described (Baugh et al. Development, 2003; Baugh et al. Nucleic Acids Research, 2001). This series of samples comprises all replicate data reported by Baugh et al. (Development, 2005).
The homeodomain protein PAL-1 specifies a lineage-specific regulatory network in the C. elegans embryo.
No sample metadata fields
View SamplesSkeletal muscle atrophy is a consequence of many diseases, environmental insults, inactivity, age and injury. Atrophy is characterized by active degradation and removal of contractile proteins and a reduction in fiber size. Animal models have been extensively used to identify pathways leading to atrophic conditions. Here we have used genome-wide expression profiling analysis and quantitative PCR to identify the molecular changes that occur in two clinically relevant animal mouse models of muscle atrophy, hindlimb casting and Achilles tendon laceration (tenotomy). Gastrocnemius muscle samples were collected 2, 7 and 14 days after insult. The total amount of muscle loss as measured by wet weight and muscle fiber size was equivalent between models, although tenotomy resulted in a more rapid induction of muscle atrophy. Furthermore, tentomy resulted in the regulation of significantly more mRNA transcripts then casting. Analysis of the regulated genes and pathways suggest that the mechanism of atrophy is distinct between these models. The degradation following casting appears ubiquitin-proteasome-mediated while degradation following tenotomy appears lysosomal and matrix-metalloproteinase (MMP)-mediated. This data suggests that there are multiple mechanisms leading to muscle atrophy and that specific therapeutic agents may be necessary to combat the atrophy seen under different conditions.
Distinct protein degradation profiles are induced by different disuse models of skeletal muscle atrophy.
Sex, Specimen part, Treatment, Time
View SamplesUterine leiomyomata, or fibroids, are benign tumors of the uterine myometrium that significantly affect up to 30% of reproductive-age women. Despite being the primary cause of hysterectomy in the United States, accounting for up to 200,000 procedures annually, the etiology of leiomyoma remains largely unknown. Due to the lack of an effective medicinal therapy for these tumors, this disease continues to have a tremendous negative impact on womens health. As a basis for understanding leiomyoma pathogenesis and identifying targets for pharmacotherapy, we conducted transcriptional profiling of leiomyoma and unaffected myometrium from humans and Eker rats, the best characterized preclinical model of leiomyoma. A global comparison of mRNA from leiomyoma versus myometrium in human and rat identified a highly significant overlap of dysregulated gene expression in leiomyoma. An unbiased pathway analysis using a method of gene set enrichment based on the Sigpathway algorithm detected the mammalian target of rapamycin (mTOR) pathway as one of the most highly upregulated pathways in both human and rat tumors. Activation of this pathway was confirmed in both human and rat leiomyomata at the protein level via Western. Inhibition of mTOR in female Eker rats with the rapamycin analog WAY-129327 for 2 weeks decreased mTOR signaling and cell proliferation in tumors, and treatment for 4 months significantly decreased tumor incidence, multiplicity and size. These results identify dysregulated mTOR signaling as a component of leiomyoma etiology across species and directly demonstrate the dependence of these tumors on mTOR signaling for growth in the Eker rat. Modulation of this pathway warrants additional investigation as a potential therapy for uterine leiomyoma.
Comparison of human and rat uterine leiomyomata: identification of a dysregulated mammalian target of rapamycin pathway.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Specimen part, Time
View SamplesBackground. Vaginal atrophy (VA) is the thinning of the vaginal epithelial lining, typically the result of lowered estrogen levels during menopause. Some of the consequences of VA include increased susceptibility to bacterial infection, pain during sexual intercourse, and vaginal burning or itching. Although estrogen treatment is highly effective, alternative therapies are also desired for women who are not candidates for hormone replacement therapy (HRT). The ovariectomized (OVX) rat is widely accepted as an appropriate animal model for many estrogen-dependent responses in humans; however, since reproductive biology can vary significantly between mammalian systems, this study examined how well the OVX rat recapitulates human biology at the transcriptional level. This report describes an analysis of expression profiling data, comparing the responses of rat and human vaginae to estrogen treatment. Results. The level of differential expression between pre- vs. post- estrogen treatment was calculated for each of the human and OVX rat datasets. Probe sets corresponding to orthologous rat and human genes were mapped to each other using NCBI Homologene. A positive correlation was observed between the rat and human responses to estrogen. Genes belonging to several biological pathways and GO categories were similarly differentially expressed in rat and human. A large number of the coordinately regulated biological processes are already known to be involved in human VA, such as inflammation, epithelial development, and EGF pathway activation. Conclusions. At the transcriptional level, there is evidence of significant overlap of the effects of estrogen treatment between the OVX rat and human VA samples.
Molecular analysis of the vaginal response to estrogens in the ovariectomized rat and postmenopausal woman.
Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The role of hypoxia in 2-butoxyethanol-induced hemangiosarcoma.
Specimen part, Treatment, Time
View SamplesThe goal of this study was to assess key molecular elements with three compounds of varying potency for hemangiosarcoma-induction.
No associated publication
Sex, Specimen part, Time
View Samples