Mammalian target of rapamycin (mTOR) is a serine/threonine kinase involved in multiple intracellular signaling pathways promoting tumor growth. mTOR is aberrantly activated in a significant portion of breast cancers and is a promising target for treatment. Rapamycin and its analogues are in clinical trials for breast cancer treatment. Patterns of gene expression (metagenes) may also be used to simulate a biologic process of effects of a drug treatment. In this study, we tested the hypothesis that the gene-expression signature regulated by rapamycin could predict disease outcome for patients with breast cancer. Results: Colony formation and sulforhodamine B (IC50 < 1nM) assays, and xenograft animals showed that MDA-MB-468 cells were sensitive to treatment with rapamycin. The comparison of in vitro and in vivo gene expression data identified a signature, termed rapamycin metagene index (RMI), of 31 genes upregulated by rapamycin treatment in vitro as well as in vivo (false discovery rate of 10%). In the Miller dataset, RMI was significantly associated with tumor size or lymph node status. High (>75) percentile) RMI was significantly associated with longer survival (P = 0.015). On multivariate analysis, RMI (P = 0.029), tumor size (P = 0.015) and lymph node status (P = 0.01) were prognostic. In van 't Veer study, RMI was not associated with the time to develop distant metastasis (P = 0.41). In Wang dataset, RMI predicted time to disease relapse (P = 0.09). Conclusions: Rapamycin-regulated gene expression signature predicts clinical outcome in breast cancer. This supports the central role of mTOR signaling in breast cancer biology and provides further impetus to pursue mTOR-targeted therapies for breast cancer treatment. Mol Cancer. 2009 Sep 24;8(1):75.
The rapamycin-regulated gene expression signature determines prognosis for breast cancer.
Specimen part, Cell line, Time
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Atrial identity is determined by a COUP-TFII regulatory network.
Age, Specimen part
View SamplesAtria and ventricles exhibit distinct molecular profiles that produce structural and functional differences between the two cardiac compartments. However, factors that determine these differences remain largely undefined. Cardiomyocyte-specific COUP- TFII ablation produces ventricularized atria that exhibit ventricle-like action potentials, increased cardiomyocyte size, and development of extensive T-tubules.
Atrial identity is determined by a COUP-TFII regulatory network.
Age, Specimen part
View SamplesCOUP-TFII, a member of the nuclear receptor superfamily plays a critical role in angiogenesis and organogenesis during embryonic development. Our results indicate that COUP-TFII expression is profoundly upregulated in prostate cancer patients and might serves as biomarker for recurrence prediction. Thus we conduct transcriptome comparison of control and COUP-TFII depleted PC3 cells to gain genomic insights on the biological processes that COUP-TFII is involved in prostate cancer cells. Ingenuity Pathway Analysis (IPA) shows that the most prominent altered pathways in the COUP-TFII depleted cells are related to cell growth; cell cycle progression and DNA damage response. Indeed many growth related genes including E2F1, p21, CDC25A, Cyclin A and Cyclin B are changed in COUP-TFII knockdown cells, suggesting that COUP-TFII might be an important regulator for prostate cancer cell growth. Further functional assays from cells and mice genetic studies confirm the hypothesis that COUP-TFII serve as the major regulator to control prostrate cancer growth. Together, results provide insight into the role of COUP-TFII in prostate tumorigenesis.
COUP-TFII inhibits TGF-β-induced growth barrier to promote prostate tumorigenesis.
Specimen part, Cell line
View SamplesGene expression patterns in the brain are strongly influenced by the severity of physiological stress at death. This agonal effect, if not well controlled, can lead to spurious findings in case-control comparisons. While many recent studies match samples by tissue pH and clinically recorded agonal conditions, we found that these commonly used indicators were sometimes at odds with observed stress-related patterns of gene expression, and that matching by these criteria still sometimes results in identifying differences between cases and controls that are primarily driven by residual agonal effects. This problem is analogous to the one in genetic studies, where race and ethnicity are often imprecise proxies for complex environmental and genetic factors.
Sample matching by inferred agonal stress in gene expression analyses of the brain.
Subject
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Deficiency of the microRNA-31-microRNA-720 pathway in the plasma and endothelial progenitor cells from patients with coronary artery disease.
Specimen part, Treatment, Time
View SamplesEarly EPCs (eEPCs) appear at less than 1 week in culture dishes, whereas late EPCs (LEPCs) appear late at 2-4 weeks. Distinct angiogenic properties between these two EPC subpopulations have been disclosed by the angiogenesis assay: late EPCs, but not eEPCs, form vascular networks de novo and are able to incorporate into vascular networks. On the contrary, eEPCs, but not late ones, indirectly augment tubulogenesis even when physically separated by a Transwell membrane, implying the involvement of a cytokine-based paracrine mechanism.
Deficiency of the microRNA-31-microRNA-720 pathway in the plasma and endothelial progenitor cells from patients with coronary artery disease.
Specimen part, Time
View SamplesHigh glucose impairs the angiogenic activities of late endothelial precursor cells (EPC). We found that far infrared (FIR) treatment restored partially the activity of late EPC. However, the mechanisms are unclear. We performed gene expression microarray analysis to assess the expression profiles of high glucose-treated late EPC with or without FIR treatment.
Deficiency of the microRNA-31-microRNA-720 pathway in the plasma and endothelial progenitor cells from patients with coronary artery disease.
Specimen part, Treatment
View SamplesTazarotene-induced gene 1 (TIG1), also named as retinoic acid receptor responder 1 (RARRES1), is a retinoid inducible type II tumor suppressor gene; the TIG1B isoform inhibits growth and invasion of cancer cells. Expression of TIG1B is frequently downregulated in various cancer tissues; however, the expression and activities of the TIG1A isoform has yet to be analyzed. This study investigated the effects of TIG1A and TIG1B isoforms on gene expression profiles of colon cancer cells. TIG1A, TIG1B and control stable clones derived from HCT116 colon cells were established using the GeneSwitch system. TIG1 isoform expression was induced upon 5 micro Molar of mifepristone (MFP) treatment for 24 hr. Biological triplicate samples were prepared and gene expression profiles were determined by microarray using human genome HGU133 plus 2 array (Affymatrix). Upon induction of TIG1A and TIG1B expression for 24 hr, a total of 129 and 55 genes were significantly altered, respectively. Of the genes analyzed, 23 and 6 genes were up- and downregulated, respectively in both TIG1A and TIG1B expressing cells.
G protein-coupled receptor kinase 5 mediates Tazarotene-induced gene 1-induced growth suppression of human colon cancer cells.
Cell line, Time
View SamplesCOUP-TFII plays a critical role in angiogenesis during development. It has also been shown to suppress Notch signaling pathway to confer vein identity. However, the downstream targets and the mechanism mediate COUP-TFII function to regulate these processes remain elusive. To identify the downstream targets and the mechanism by which COUP-TFII regulates agiogenesis and vein specification, we knocked down COUP-TFII in HUVEC cells using COUP-TFII specific siRNA and used microarray analysis to identify downstream targets. Interestingly, we found the expression of many genes in the cell cycle pathway and Notch signaling pathway are significantly altered in the COUP-TFII depleted cells.
COUP-TFII is a major regulator of cell cycle and Notch signaling pathways.
Specimen part
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