Intratumoral heterogeneity may generate a diversity of resistance mechanisms that could cause different therapeutic responses in different cell populations.
Breast cancer cells respond differentially to modulation of TGFβ2 signaling after exposure to chemotherapy or hypoxia.
Cell line
View SamplesTo understand the effects of glutamine deprivation on cell physiology we performed global analysis of gene expression in response to glutamine deprivation.
Glutamine deprivation stimulates mTOR-JNK-dependent chemokine secretion.
Cell line
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Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesInduced pluripotent stem cells (iPSCs) can be generated by enforced expression of defined transcription factors in somatic cells. It remains controversial whether iPSCs are equivalent to blastocyst-derived embryonic stem cells (ESCs). Using genetically matched cells, we found that the overall mRNA expression patterns of these cell types are indistinguishable with the exception of a few transcripts encoded on chromosome 12qF1.
Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesUnderstanding the biological potential of fetal stem/progenitor cells will help define mechanisms in liver development and homeostasis. We isolated epithelial fetal human liver cells and established phenotype-specific changes in gene expression during continuous culture conditions. Fetal human liver epithelial cells displayed stem cell properties with multilineage gene expression, extensive proliferation and generation of mesenchymal lineage cells, although the initial epithelial phenotype was rapidly supplanted by meso-endodermal phenotype in culture. This meso-endodermal phenotype was genetically regulated through cytokine signaling, including transforming growth factor-b, bone morphogenetic protein, fibroblast growth factors, and other signaling pathways. Reactivation of HNF-3a (FOXA1) transcription factor, a driver of hepatic specification in the primitive endoderm, indicated that the meso-endodermal phenotype represented an earlier developmental stage of cells. We found that fetal liver epithelial cells formed mature hepatocytes in vivo, including after genetic manipulation using lentiviral vectors, offering convenient assays for analysis of further cell differentiation and fate. Taken together, these studies demonstrated plasticity in fetal liver epithelial stem/progenitor cells, offered paradigms for defining mechanisms regulating lineage switching in stem/progenitor cells, and provided potential avenues for regulating cell phenotypes for applications of stem/progenitor cells, such as for cell therapy.
Phenotype reversion in fetal human liver epithelial cells identifies the role of an intermediate meso-endodermal stage before hepatic maturation.
Specimen part
View SamplesPluripotent cells can be derived from somatic cells by either overexpression of defined transcription factors (resulting in induced pluripotent stem cells (iPSCs)) or by nuclear transfer or cloning (resulting in NT-ESCs). To determine whether cloning further reprograms iPSCs, we used iPSCs as donor cells in nuclear transfer experiments.
Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesThis study was undertaken to test the hypothesis that short term exposure (4 hours) to physiologic hyperinsulinemia in normal, healthy subjects without a family history of diabetes would induce a low grade inflammatory response, independently of glycemic status. We performed euglycemic hyperinsulinemic (80 mU/m2/min) clamps in 12 healthy, insulin sensitive subjects with no family history of diabetes followed by biopsies of the vastus lateralis muscle taken basally and after 30 and 240 minutes of insulin infusion. Gene expression profiles were generated using Affymetrix HG-U133A arrays. No probe sets had significantly altered expression at 30 minutes of the insulin clamp, but 121 probe sets (117 upregulated and 4 downregulated) were significantly altered after 240 minutes. Hyperinsulinemia in normal, healthy human subjects increased the mRNAs for a number of inflammatory genes and transcription factors. Microarray and quantitative RT-PCR revealed the upregulation of chemokine, cc motif, ligand 2 (CCL2), CCL8, thrombomodulin (THBD), ras-related associated with diabetes (RRAD), metallothionein (MT), and serum/glucocorticoid regulated kinase (SGK), and downregulation of CITED2 (a CREB-binding protein-interacting transactivator), a known coactivator of PPAR-alpha. Interestingly, SGK and CITED2 are located at chromosome 6q23, where we previously detected strong linkage to hyperinsulinemia. A control saline infusion performed on 3 normal, healthy subjects without a family history of diabetes demonstrated that the genes altered following the euglycemic-hyperinsulinemic clamp were due to insulin and independent of biopsy removal. This study demonstrates that insulin acutely regulates the expression of genes involved in inflammation and transcription, and identifies several candidate genes/pathways for further investigation.
Effect of acute physiological hyperinsulinemia on gene expression in human skeletal muscle in vivo.
Sex, Race
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Contribution of stress responses to antibiotic tolerance in Pseudomonas aeruginosa biofilms.
No sample metadata fields
View SamplesMicroarray analysis was used to identify changes in the level of transcription of genes in P. aeruginosa drip flow biofilms in response to ciprofloxacin and tobramycin exposure. This data was evaluated and used to select strains that carry transposon mutations in genes that might play a role in antibiotic tolerance of biofilms. The strains were evaluated for defects in biofilm tolerance.
Contribution of stress responses to antibiotic tolerance in Pseudomonas aeruginosa biofilms.
No sample metadata fields
View SamplesTranscriptome analysis was applied to characterize the physiological activities of Psuedomonas aeruginosa cells grown for three days in drip flow biofilm reactors when compared to the activities of P. aeruginosa grown planktonically to exponential phase in the same media. Here, rather than examining the effect of an individual gene on biofilm antibiotic tolerance, we used a transcriptomics approach to identify regulons and groups of related genes that are induced during biofilm growth of Pseudomonas aeruginosa. We then tested for statistically significant overlap between the biofilm-induced genes and independently compiled gene lists corresponding to stress responses and other putative antibiotic protective mechanisms. This data was evaluated and used to select strains that carry transposon mutations in genes that might play a role in antibiotic tolerance of biofilms. The strains were evaluated for defects in biofilm tolerance.
Contribution of stress responses to antibiotic tolerance in Pseudomonas aeruginosa biofilms.
No sample metadata fields
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