Hyperactivation of phosphatidylinositol-3 kinase (PI3K) promotes escape from hormone dependence in estrogen receptor-positive breast cancer.
Hyperactivation of phosphatidylinositol-3 kinase promotes escape from hormone dependence in estrogen receptor-positive human breast cancer.
Specimen part, Cell line
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ERα-dependent E2F transcription can mediate resistance to estrogen deprivation in human breast cancer.
Specimen part, Cell line, Treatment
View SamplesA significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation. To model resistance to aromatase inhibitor (AI) therapy, long-term estrogen-deprived (LTED) derivatives of MCF-7 and HCC-1428 cells were generated through culture for 3 and 7 months under hormone-depleted conditions, respectively. These LTED cells showed sensitivity to the ER downregulator fulvestrant under hormone-depleted conditions, suggesting continued dependence upon ER signaling for hormone-independent growth. To evaluate the role of ER in hormone-independent growth, LTED cells were treated +/- 1 uM fulvestrant x 48 h before RNA was harvested for gene expression analysis.
ERα-dependent E2F transcription can mediate resistance to estrogen deprivation in human breast cancer.
Specimen part, Cell line, Treatment
View SamplesA significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation.
A kinome-wide screen identifies the insulin/IGF-I receptor pathway as a mechanism of escape from hormone dependence in breast cancer.
Cell line, Treatment
View SamplesAtrial fibrillation (AF) is a progressive arrhythmia for which current therapy is inadequate. During AF, rapid stimulation causes atrial remodeling that promotes further AF. The cellular signals that trigger this process remain poorly understood, however, and elucidation of these factors would likely identify new therapeutic targets. We have previously shown that immortalized mouse atrial (HL-1) myocytes subjected to 24 hr of rapid stimulation in culture undergo remodeling similar to that seen in animal models of atrial tachycardia (AT) and human AF. This preparation is devoid of confounding in vivo variables that can modulate gene expression (e.g., hemodynamics). Therefore, we investigated the transcriptional profile associated with early atrial cell remodeling. RNA was harvested from HL-1 cells cultured for 24 hr in the absence and presence of rapid stimulation and subjected to microarray analysis. Data were normalized using Robust Multichip Analysis (RMA), and genes exhibiting significant differential expression were identified using the Significance Analysis of Microarrays (SAM) method. Using this approach, 919 genes were identified that were significantly altered with rapid stimulation (763 up-regulated and 156 down-regulated). For many individual transcripts, changes typical of AF/AT were observed, with marked up-regulation of genes encoding BNP and ANP precursors, heat shock proteins, and MAP kinases, while novel signaling pathways and molecules were also identified. Both stress and survival response were evident, as well as up-regulation of multiple transcription factors. Genes were also functionally classified based on cellular component, biologic process, and molecular function using the Gene Ontology database to permit direct comparison of our data with other gene sets regulated in human AF and experimental AT. For broad categories of genes grouped by functional classification, there was striking conservation between rapidly stimulated HL-1 cells and AF/AT. Results were confirmed using real-time quantitative RT-PCR on 13 genes selected by physiological relevance in AF/AT and regulation in the microarray analysis (up, down, and nonregulated). Rapidly-stimulated atrial myocytes provide a complementary experimental paradigm to explore the initial cellular signals in AT remodeling to identify novel targets in the treatment of AF.
Transcriptional remodeling of rapidly stimulated HL-1 atrial myocytes exhibits concordance with human atrial fibrillation.
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View SamplesWe quantified differential gene (mRNA) expression in human coronary artery cells treated with native HDL, reconstituted HDL, lipid-free apolipoprotein A-I, small unilamellar vesicles, or PBS control.
HDL-transferred microRNA-223 regulates ICAM-1 expression in endothelial cells.
Specimen part
View SamplesWild-type c57Bl/6 mice were placed on high-fat diet (21% fat) for 3 weeks, and total RNA from liver was used for affymetrix microarray analysis. Data were analyzed using GeneSpring GX12.0.
No associated publication
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View SamplesOxidative injury and inflammation have been implicated in the genesis of hypertension but the mechanisms involved are not fully understood. We describe a new pathway in which angiotensin II promotes dendritic cell (DC) activation of T cells and ultimately hypertension. NADPH oxidase-dependent superoxide production is increased 5-fold in DCs isolated from hypertensive mice as compared to sham-treated mice. This is associated with DC accumulation of protein-isoketal adducts and production of IL-6, IL-1 and IL-23. DCs from hypertensive mice but not sham mice promote survival and proliferation of CD8+ T cells in culture. Chemically diverse isoketal scavengers not only prevent activation and immunogenicity of DCs, but also attenuate angiotensin II-induced hypertension. Moreover, adaptive transfer of DCs from hypertensive mice prime development of hypertension in response to a subpressor dose of angiotensin II. Exposure of DCs to tert butyl hypdroperoxide promoted isoketal formation, DC stimulation of CD8+ T cell proliferation and primed hypertension in response to low dose angiotensin II. Serum isoprostanes, precursors to isoketals, were found to be elevated in humans with treated hypertension and were markedly elevated in patients with resistant hypertension. These studies show that angiotensin II-induced hypertension activates DCs, in large part by causing superoxide production and formation of isoketals. They define a new mechanism of hypertension and identify a potential new therapeutic approach for this disease.
DC isoketal-modified proteins activate T cells and promote hypertension.
Age, Specimen part
View SamplesVascular smooth muscle cells (VSMCs) are derived from distinct embryonic origins. Vessels originating from differing smooth muscle cell populations have distinct vascular and pathological properties of calcification, atherosclerosis, and structural defects such as aneurysm and coarctation. We hypothesized that domains within a vessel vary in phenotype based on embryonic origin.
No associated publication
Age, Specimen part
View SamplesThe ductus arteriosus (DA) is a fetal vascular shunt that is located between the main pulmonary artery and the aorta. Oxygenated fetal blood from the placenta is shunted past the uninflated fetal lungs, crosses the DA, and is then available to the peripheral organs. In utero closure of the DA is deleterious, but postnatal closure of the DA is necessary for establishment of pulmonary circulation and the transition to newborn life.
Transcriptional profiling reveals ductus arteriosus-specific genes that regulate vascular tone.
Specimen part
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