Cardiac disease accounts for the largest proportion of adult mortality and morbidity in the industrialized world. However, progress toward improved clinical treatments is hampered by an incomplete understanding of the genetic programs controlling early cardiogenesis. To better understand this process, we set out to identify genes whose expression is enriched within early cardiac fated populations, obtaining the transcriptional signatures of mouse embryonic stem cells (mESCs) differentiating along a cardiac path.
Efficient array-based identification of novel cardiac genes through differentiation of mouse ESCs.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Toward Signaling-Driven Biomarkers Immune to Normal Tissue Contamination.
Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Expression profiling of human basophils: modulation by cytokines and secretagogues.
Specimen part, Treatment
View SamplesPatients with oncogene driven tumors are currently treated with targeted therapeutics such as epidermal growth factor receptor (EGFR) inhibitors. The inhibited oncogenic pathway often interacts with other signaling pathways and alters predicted therapeutic response. Genomic data from The Cancer Genome Atlas (TCGA) demonstrates pervasive molecular alterations to EGFR, MAPK, and PI3K signaling in previously untreated tumors. Therefore, this study uses bioinformatics algorithms to infer the complex pathway interactions that result from EGFR inhibitor use in cancer cells that contain these these common EGFR network genetic alterations. To do this, we modified the HaCaT keratinocyte cell line model of premalignancy to simulate cancer cells with constitutive activation of EGFR, HRAS, and PI3K in a controlled genetic background. We then measured gene expression after treating modified HaCaT cells with three EGFR targeted agents (gefitinib, afatinib, and cetuximab) for 24 hours.
CoGAPS matrix factorization algorithm identifies transcriptional changes in AP-2alpha target genes in feedback from therapeutic inhibition of the EGFR network.
Cell line, Treatment
View SamplesBackground & Aims: Chronic hepatitis C virus (HCV) infection is complicated by hepatic fibrosis. Hypothesizing that fibrogenic signals may originate in cells susceptible to HCV infection, gene expression of hepatocytes was analyzed from persons with chronic HCV at different stages of liver fibrosis. Methods: HCV-infected subjects with significant liver fibrosis (Ishak fibrosis 3) were matched for age, race, and gender to subjects with minimal fibrosis (Ishak fibrosis 0-1). RNA from portal tracts and hepatic parenchyma was isolated from biopsies by laser capture and transcriptome profiling was performed using hybridization arrays. Results: Portal tracts from both groups were enriched for immune related genes when compared to hepatocytes but high fibrosis subjects showed a loss of this enrichment. Hepatocytes from persons with high fibrosis were depleted for genes involved in small molecule and drug metabolism, especially butyrylcholinesterase (BCHE), a gene involved in the metabolism of drugs of abuse. Differential expression of BCHE was validated in the same tissues using qPCR. Cross-sectional and longitudinal testing in an expanded cohort of HCV-infected individuals showed that serum BCHE activity decreased in advance of progression to fibrosis. Conclusion: Chronic HCV infection is associated with a loss of hepatocyte metabolic function, decreased enrichment of immune-related genes in portal tracts and downregulation of BCHE in hepatocytes. Our results indicate that BCHE may be involved in the progression of fibrosis during HCV infection among injection drug users and may serve as a useful marker for fibrosis progression.
Laser captured hepatocytes show association of butyrylcholinesterase gene loss and fibrosis progression in hepatitis C-infected drug users.
Sex, Age, Race
View SamplesThis study integrated Affymetrix SNPchip data for CNV estimation, Affymetrix HuEx1.0 data for gene expression estimation, and Illumina HumanMethylation27k BeadChip data for promoter methylation to estimate pathway activity
Activation of the NOTCH pathway in head and neck cancer.
Disease, Disease stage
View SamplesAberrant activation of signaling pathways controlled in normal epithelial cells by the epidermal growth factor receptor (EGFR) has been linked to cetuximab (a monoclonal antibody against EGFR) resistance in head and neck squamous cell carcinoma (HNSCC). To infer relevant and specific pathway activation downstream of EGFR from gene expression in HNSCC, we generated gene expression signatures using immortalized keratinocytes (HaCaT) subjected to either ligand stimulation or pharmacological inhibition of the signaling intermediaries PI-3-Kinase and MEK or transfected with EGFR, RELA/p65, or HRASVal12. The gene expression patterns that distinguished the various HaCaT variants and conditions were inferred using the Markov chain Monte Carlo (MCMC) matrix factorization algorithm Coordinated Gene Activity in Pattern Sets (CoGAPS). This approach inferred gene expression signatures with greater relevance to cell signaling pathway activation than the expression signatures inferred with standard linear models. Furthermore, the pathway signature generated using HaCaT-HRASVal12 further associated with the cetuximab treatment response in isogenic cetuximab-sensitive (UMSCC1) and -resistant (1CC8) cell lines. Our data suggest that the CoGAPS algorithm can generate gene expression signatures that are pertinent to downstream effects of receptor signaling pathway activation and potentially be useful in modeling resistance mechanisms to targeted therapies.
Gene expression signatures modulated by epidermal growth factor receptor activation and their relationship to cetuximab resistance in head and neck squamous cell carcinoma.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Differential gene expression profiles are dependent upon method of peripheral blood collection and RNA isolation.
No sample metadata fields
View SamplesGene expression was measured on the Affymetrix platform in primary xenografts, xenograft-derived cell lines, secondary xenografts, normal lung, and primary tumors obtained from chemotherapy naive Small Cell Lung Cancer (SCLC). The SCLC primary xenografts were serially propagated in vivo in immunodeficient mice. Cell lines were derived from each xenograft and grown for 6 months using conventional tissue culture conditions. Secondary xenografts were obtained from cell cultures by re-implantation in immunodeficient mice. Such SCLC laboratory models were analyzed along with conventional SCLC cell lines and the derivative secondary xenografts, with normal lung and primary tumors, to assess irreversible gene expression changes induced by culturing conditions.
A primary xenograft model of small-cell lung cancer reveals irreversible changes in gene expression imposed by culture in vitro.
Disease, Disease stage, Cell line
View SamplesMotivation: Sample source, procurement process, and other technical variations introduce batch effects into genomics data. Algorithms to remove these artifacts enhance differences between known biological covariates, but also carry potential concern of removing intra-group biological heterogeneity and thus any personalized genomic signatures. As a result, accurate identification of novel subtypes from batch corrected genomics data is challenging using standard algorithms designed to remove batch effects for class comparison analyses. Nor can batch effects be corrected reliably in future applications of genomics-based clinical tests, in which the biological groups are by definition unknown a priori.
Preserving biological heterogeneity with a permuted surrogate variable analysis for genomics batch correction.
Sex, Specimen part, Disease, Disease stage, Race
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