In this study, we have utilized microarray analysis to directly compare a subset of structurally distinct, clinically relevant SERMs in the presence and absence of estradiol, using a high replicate number (10) to ensure detection of modestly regulated genes.
Research resource: Transcriptional profiling in a cellular model of breast cancer reveals functional and mechanistic differences between clinically relevant SERM and between SERM/estrogen complexes.
Cell line
View SamplesWe report that decreased expression and activity of AhR exacerbates murine neovascular age-related macular degeneration, and increases cell migration and tube formation. The mechanism involves increased expression of pro-angiogenic mediators and altered matrix degradation. The results of our study suggest that the AhR signaling pathway may be important in multiple AMD related pathways. Overall design: Gene expression analysis in the retinal pigment epithelium (RPE)-choroid tissue from AhR knockout mice contrasted against wild-type age-matched controls.
Aryl hydrocarbon receptor knock-out exacerbates choroidal neovascularization via multiple pathogenic pathways.
No sample metadata fields
View SamplesThis dataset is part of the manuscript titled "The metabolic regulator ERRalpha, a downstream target of HER2/IGF1, as a therapeutic target in breast cancer" (in review). The expression data obtained in human mammary epithelial cells were used to generate a list of ERRalpha-regulated genes that was later refined in clinical breast cancer datasets to generate a clinically relevant signature of ERalpha activity (referred to as Cluster 3 signature). Using this signature of the estrogen-related receptor alpha (ERRa) to profile more than eight-hundred breast tumors, we found that patients with tumors exhibiting higher ERRa activity were predicted to have shorter disease free survival. Further, the ability of an ERRa antagonist, XCT790, to inhibit breast cancer cell proliferation correlates with the cells intrinsic ERRa activity. These findings highlight the potential of using the ERRa signature and antagonists in targeted therapy for breast cancer. Using a chemical genomic approach we determined that activation of the HER2/IGF1 signaling pathways upregulates the expression of PGC-1b, an obligate cofactor for ERRa activity. Knockdown of PGC-1b in HER2 positive breast cancer cells impaired ERRa signaling and reduced cell proliferation, implicating a functional role of PGC1b/ERRa in the pathogenesis HER2 positive breast cancer.
The metabolic regulator ERRα, a downstream target of HER2/IGF-1R, as a therapeutic target in breast cancer.
Specimen part
View SamplesOrphan nuclear receptor estrogen-related receptor alpha (ERR) has recently been shown to carry negative prognostic significance in breast and ovarian cancers. The specific role of ERR in tumor growth and progression, however, is yet to be fully understood. The significant homology between estrogen receptor alpha (ER) and ERR initially suggested that these receptors may share similar transcriptional targets. Using the well-characterized ER-positive MCF-7 breast cancer cell line, we sought to gain a genome-wide picture of ER-ERR cross-talk using an unbiased microarray approach.
Estrogen-related receptor alpha is critical for the growth of estrogen receptor-negative breast cancer.
Cell line, Treatment
View SamplesBoth pro- and anti-mitogenic activities have been ascribed to progesterone receptor (PR) agonists and antagonists in breast cancer cells, however, the transcriptional responses that underlie these paradoxical functions are not apparent. Using non-transformed, normal human mammary epithelial cells (hMECs) engineered to express PR, and standard microarray technology, we defined 2,370 genes that were significantly regulated by the PR agonist R5020. Gene Ontology (GO) analysis revealed that GO-terms involved in inflammation and NF-B signaling were among the most significantly regulated. Interestingly, on those NF-B responsive genes that were inhibited by agonist-activated PR, antagonists either (a) mimicked the actions of agonists or (b) reversed the inhibitory actions of agonists. This difference in pharmacological response could be attributed to the fact that although agonist and antagonist-activated PR is recruited to the promoters of NF-B responsive promoters, the physical presence of PR tethered to the promoter of some genes is sufficient for transcriptional inhibition whereas on others an agonist-activated PR conformation is required for inhibition of NF-B signaling. Importantly, the actions of PR on the latter class of genes were reversed by an AF-2 inhibiting, LXXLL-containing peptide. Consideration of the relative activities of these distinct anti-inflammatory pathways in breast cancer may be instructive with respect to the likely therapeutic activity of PR agonists or antagonists in the treatment of breast cancer.
Mechanisms of progesterone receptor inhibition of inflammatory responses in cellular models of breast cancer.
Specimen part
View SamplesWe have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful Selective Androgen Receptor Modulators (SARMs). As one of the approaches, we used a DNA microarray analysis to demonstrate that differently conformed receptors facilitate distinct patterns of gene expression in LNCaP cells. Interestingly, we observed a complete overlap in the identity of genes expressed following treatment with mechanistically distinct AR ligands. However, it was differences in the kinetics of gene regulation that distinguished these compounds. Follow-up studies, in cell-based assays of AR action, confirmed the importance of these alterations in gene expression. Together these studies demonstrate an important link between AR structure, gene expression and biological outcome.
Linking ligand-induced alterations in androgen receptor structure to differential gene expression: a first step in the rational design of selective androgen receptor modulators.
No sample metadata fields
View SamplesPGC-1 transcription factor was customized to limit its interations to ERRalpha. This mutant (2x9) was used to dissect the transcription activation patterns that are attributable to the PGC1-ERR interaction and PGC-1 actions that are independent of ERR. Inactive mutant with the deleted LLXXL motifs (L2L3) and wt PGC-1 were used as negative and positive controls respectively. BGAL-expressing construct was used to control for non-specific effects of adenoviral infection.
Receptor-selective coactivators as tools to define the biology of specific receptor-coactivator pairs.
No sample metadata fields
View SamplesERRa is an orphan nuclear receptor with an established role in cell metabolism. Our studies demonstrate that acute or chronic loss of ERRa broadly affects mitochondrial and glycolytic metabolism in CD4+ T cells and results in diminished T cell function and differentation.
Estrogen-related receptor-α is a metabolic regulator of effector T-cell activation and differentiation.
Specimen part, Treatment
View SamplesWe applied a systems biology approach to study immune responses in subjects receiving 3 consecutive immunizations with RTS,S/AS01 (RRR), or in those receiving 2 immunizations of RTS,S/AS01, following a primary immunization with adenoviral Ad35 (ARR) vector expressing circumsporozoite protein.
Systems analysis of protective immune responses to RTS,S malaria vaccination in humans.
Specimen part, Disease stage, Subject, Time
View SamplesThe Rac nucleotide Exchange Factor (Rac-GEF) P-Rex1 is highly expressed in breast cancer, specifically in the luminal subtype, and is an essential mediator of actin cytoskeleton reorganization and cell migratory responses induced by ErbB and other tyrosine-kinase receptors. Heregulin, a growth factor highly expressed in mammary tumors, causes the activation of P-Rex1 and Rac1 in breast cancer cells via ErbB3, leading to a motile response. Since there is limited information about P-Rex1 downstream effectors, we carried out a microarray analysis to identify genes regulated by P-Rex1 in the context of HRG stimulation. In T-47D breast cancer cells, HRG treatment caused major changes in gene expression, including genes associated with motility, adhesion, invasiveness and metastasis. Silencing P-Rex1 expression from T-47D cells using RNAi altered the induction and repression of a subset of HRG-regulated genes, among them genes associated with extracellular matrix organization, migration, and chemotaxis. HRG induction of MMP10, a gene encoding for metalloproteinase-10, was found to be highly sensitive both to P-Rex1 depletion as well as inhibition of Rac1 function by the GTPase Activating Protein (GAP) 2-chimaerin, suggesting the dependence of the P-Rex1/Rac1 pathway for the induction of genes critical for breast cancer invasiveness. Notably, there is a significant association in the expression of P-Rex1 and MMP10 in human luminal breast cancer, and their co-expression is indicative of poor prognosis.
Characterization of a P-Rex1 gene signature in breast cancer cells.
No sample metadata fields
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