Foxp3+ regulatory T (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely . Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of inter-cellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA-biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg cell-mediated suppression mediated by miRNA-containing exosomes.
MicroRNA-containing T-regulatory-cell-derived exosomes suppress pathogenic T helper 1 cells.
Specimen part
View SamplesGene expression of Treg cells that have lost Foxp3 expression and acquired Il4 expression following adoptive transfer into T-cell deficient mice (HpTR-IL-4gfp+), cmpared to conventional Treg cells isolated from H. polygyrus-infected wild-type mice (HpTR) and Th2 cells generated from nave T cells following adoptive transfer into H. polygyrus-infected T-cell deficient mice (nT-IL-4gfp+).
Interleukin 4 promotes the development of ex-Foxp3 Th2 cells during immunity to intestinal helminths.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide analysis in human colorectal cancer cells reveals ischemia-mediated expression of motility genes via DNA hypomethylation.
Cell line, Treatment
View SamplesDNA hypomethylation is an important epigenetic modification found to occur in many different cancer types, leading to the upregulation of previously silenced genes and loss of genomic stability. We previously demonstrated that hypoxia and hypoglycaemia (ischemia), two common micro-environmental changes in solid tumors, decrease DNA methylation through the downregulation of DNMTs in human colorectal cancer cells. Here, we utilized a genome-wide cross-platform approach to identify genes hypomethylated and upregulated by ischemia. Following exposure to hypoxia or hypoglycaemia, methylated DNA from human colorectal cancer cells (HCT116) was immunoprecipitated and analysed with an Affymetrix promoter array. Additionally, RNA was isolated and analysed in parallel with an Affymetrix expression array. Ingenuity pathway analysis software revealed that a significant proportion of the genes hypomethylated and upregulated were involved in cellular movement, including PLAUR and CYR61. A Matrigel invasion assay revealed that indeed HCT116 cells grown in hypoxic or hypoglycaemic conditions have increased mobility capabilities. Confirmation of upregulated expression of cellular movement genes was performed with qPCR. The correlation between ischemia and metastasis is well established in cancer progression, but the molecular mechanisms responsible for this common observation have not been clearly identified. Our novel results suggest that hypoxia and hypoglycaemia may be driving changes in DNA methylation through downregulation of DNMTs. This is the first report to our knowledge that provides an explanation for the increased metastatic potential seen in ischemic cells; i.e. that ischemia could be driving DNA hypomethylation and increasing expression of cellular movement genes.
Genome-wide analysis in human colorectal cancer cells reveals ischemia-mediated expression of motility genes via DNA hypomethylation.
Cell line, Treatment
View SamplesUsing Affymetrix HG-U133-Plus 2.0 array and Laser Capture Microdissection techniques, we determined whether growth in different zones of the same tumor affected expression of genes by human pancreatic cancer cells. Human L3.6pl pancreatic cancer cells were implanted into the pancreas of nude mice. Gene expression patterns in tumor cells within the central and peripheral zones were compared and statistical differences were determined for 1222 genes. Bioinformatic functional prediction analysis revealed that 346 upregulated genes in the peripheral zone were related to cytoskeleton organization and biogenesis, cell cycle, cell adhesion, cell motility, DNA replication, localization, integrin-mediated signaling pathway, development, morphogenesis, and IkB kinase/NF-kB cascade; and 876 upregulated genes in the central zone were related with regulation of cell proliferation, regulation of transcription, transmembrane receptor protein tyrosine kinase signaling pathway, response to stress, small GTPase mediated signal transduction, hexose metabolism, cell death, response to external stimulus, carbohydrate metabolism, and response to wounding. Results from the microarray were confirmed for reliability by in situ hybridization analysis. Collectively, these data demonstrate zonal heterogeneity for gene expression profiles in tumors and suggest that characterization of zonal gene expression profiles are essential to obtain reproducible data, to predict disease prognosis, and to design specific therapeutics.
Zonal heterogeneity for gene expression in human pancreatic carcinoma.
No sample metadata fields
View SamplesGene expression profiles in Ba/F3 cells expressing ETV6-PDGFRB, FIP1L1-PDGFRA or a control vector, treated or not with imatinib (Glivec)
The expression of the tumour suppressor HBP1 is down-regulated by growth factors via the PI3K/PKB/FOXO pathway.
Specimen part, Cell line, Treatment
View SamplesThe requirement of frozen tissues for microarray experiments limits the clinical usage of genome-wide expression profiling using microarray technology.
Robust gene expression signature from formalin-fixed paraffin-embedded samples predicts prognosis of non-small-cell lung cancer patients.
Sex, Specimen part, Race
View SamplesWe have replaced the right arm of chromosome IX in Saccharomyces cerevisiae with a synthetic version to generate synIXR haploids. The synthetic chromosome features multiple sequeunce modifications.
Synthetic chromosome arms function in yeast and generate phenotypic diversity by design.
Specimen part
View SamplesDespite continual efforts to rationalize a prognostic stratification of patients with esophageal adenocarcinoma (EAC) before treatment, current staging system only shows limited success owing to the lack of molecular and genetic markers that reflect prognostic features of the tumor. To develop molecular predictors of prognosis, we used systems-level characterization of tumor transcriptome. Using DNA microarray, genome-wide gene expression profiling was performed on 75 biopsy samples from patients with untreated EAC. Various statistical and informatical methods were applied to gene expression data to identify potential biomarkers associated with prognosis. Potential marker genes were validated in an independent cohort using quantitiative RT-PCR to measure gene expression. Distinct subgroups of EAC were uncovered by systems-level characterization of tumor transcriptome. We also identified a six-gene expression signature that could be used to predict overall survival (OS) of EAC patients. In particular, expression of SPARC and SPP1 was a strong independent predictor of OS, and a combined gene expression signature with these two genes was associated with prognosis (P < 0.024), even when all relevant pathological variables were considered together in multivariate Cox hazard regression analysis. Our findings suggest that molecular features reflected in gene expression signatures may dictate the prognosis of EAC patients, and these gene expression signatures can be used to predict the likelihood of prognosis at the time of diagnosis and before treatment.
Prognostic biomarkers for esophageal adenocarcinoma identified by analysis of tumor transcriptome.
No sample metadata fields
View SamplesPrevious work has shown that lung tumors and normal-appearing adjacent lung tissues share specific abnormalities that may be highly pertinent to the pathogenesis of lung cancer. However, the global and molecular adjacent airway field cancerization in non-small cell lung cancer (NSCLC) has not been characterized before.
Transcriptomic architecture of the adjacent airway field cancerization in non-small cell lung cancer.
Specimen part
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