Cancer is a disease of both genetic and epigenetic changes. While increasing evidence demonstrates that oncogenic progression entails chromatin-mediated changes such as DNA methylation, the role of histone variants in cancer initiation and progression currently remains unexplored. Here, we report that the histone variant macroH2A (mH2A) suppresses tumour progression of malignant melanoma.
The histone variant macroH2A suppresses melanoma progression through regulation of CDK8.
Specimen part, Disease
View SamplesStudies were undertaken to determine whether oscillatory behavior in the extracellular signal regulated kinase (ERK) pathway results in unique gene regulation patterns. Microarray analysis was performed on three subcloned populations of human keratinocytes with distinct ERK signaling/oscillation phenotypes.
ERK oscillation-dependent gene expression patterns and deregulation by stress response.
Specimen part
View SamplesRecognition and removal of apoptotic cells by professional phagocytes, including dendritic cells and macrophages, preserve self-tolerance and prevent chronic inflammation and autoimmune pathologies. However the diverse array of phagocytes residing within different tissues combined with the necessarily prompt nature of apoptotic cell clearance has made it difficult to study this process in situ. Thus, the full spectrum of functions executed by tissue resident phagocytes in response to homeostatic apoptosis remains unclear.
Different tissue phagocytes sample apoptotic cells to direct distinct homeostasis programs.
Sex, Specimen part
View SamplesRNA-Sequencing is a transformative method that captures the quantitative dynamics of a transcriptome with exquisite sensitivity and single-base resolution. There are, however, few computational pipelines for RNA-Seq with statistical tests that evince sufficient robustness and power as demanded by the difficult combination of small sample sizes and high variability in sequence read counts. To this end, we developed GENE-counter, a complete software pipeline for analyzing RNA-Seq data for genome-wide expression differences between replicated treatment groups. One important component of GENE-counter is a statistical test based on the NBP parameterization of the negative binomial distribution for identifying differentially expressed genome features. We used GENE-counter to analyze RNA-Seq data derived from Arabidopsis thaliana infected with a strain of defense-eliciting bacteria. We identified 308 genes that were differentially induced. Using alternative methods, we provided support for the induced expression and biological relevance of a substantial proportion of the genes. These results suggest the NBP parameterization of the negative binomial distribution is well suited for explaining RNA-Seq data and the statistical test makes GENE-counter a powerful pipeline for studying genome-wide expression changes. GENE-counter is freely available at http://changlab.cgrb.oregonstate.edu/.
GENE-counter: a computational pipeline for the analysis of RNA-Seq data for gene expression differences.
Treatment
View SamplesVolunteers were assessed at study entry, the day of the third vaccination and 24, 72 hours, two weeks after vaccination, and 5 days after challenge. 13/39 vaccinees were protected and 26/39 were not protected. Eleven vaccinees exhibited delayed onset of parasitemia. All infectivity controls developed parasitemia. Prediction Analysis of Microarrays (PAM-R) identified genes corresponding with protection. Gene Set Enrichment Analysis (GSEA) identified sets of genes associated with protection after the third immunization, before challenge.
Expression of genes associated with immunoproteasome processing of major histocompatibility complex peptides is indicative of protection with adjuvanted RTS,S malaria vaccine.
Specimen part
View SamplesDespite initial and often dramatic responses of epidermal growth factor receptor (EGFR)-addicted lung tumors to the EGFR-specific tyrosine kinase inhibitors (TKIs), gefitinib and erlotinib, nearly all develop resistance and relapse. To explore novel mechanisms mediating acquired resistance, we employed non-small-cell lung cancer (NSCLC) cell lines bearing activating mutations in EGFR and rendered them resistant to EGFR-specific TKIs through chronic adaptation in tissue culture. In addition to previously observed resistance mechanisms including EGFR-T790M ''gate-keeper'' mutations and MET amplification, a subset of the seven chronically adapted NSCLC cell lines including HCC4006, HCC2279 and H1650 cells exhibited marked induction of fibroblast growth factor (FGF) 2 and FGF receptor 1 (FGFR1) mRNA and protein. Also, adaptation to EGFR-specific TKIs was accompanied by an epithelial to mesenchymal transition (EMT) as assessed by changes in CDH1, VIM, ZEB1 and ZEB2 expression and altered growth properties in Matrigel. In adapted cell lines exhibiting increased FGF2 and FGFR1 expression, measures of growth and signaling, but not EMT, were blocked by FGFR-specific TKIs, an FGF-ligand trap and FGFR1 silencing with RNAi. In parental HCC4006 cells, cell growth was strongly inhibited by gefitinib, although drug-resistant clones progress within 10 days. Combined treatment with gefitinib and AZD4547, an FGFR-specific TKI, prevented the outgrowth of drug-resistant clones. Thus, induction of FGF2 and FGFR1 following chronic adaptation to EGFR-specific TKIs provides a novel autocrine receptor tyrosine kinase-driven bypass pathway in a subset of lung cancer cell lines that are initially sensitive to EGFR-specific TKIs. The findings support FGFR-specific TKIs as potentially valuable additions to existing targeted therapeutic strategies with EGFR-specific TKIs to prevent or delay acquired resistance in EGFR-driven NSCLC. Overall design: Examination of mRNA levels in DMSO and gefitinib-resistant cultures of HCC4006 and HCC827. Each group has two replicates.
A mechanism of resistance to gefitinib mediated by cellular reprogramming and the acquisition of an FGF2-FGFR1 autocrine growth loop.
Specimen part, Cell line, Treatment, Subject
View SamplesDuring development, neural crest cells are induced by signaling events at the neural plate border of all vertebrate embryos. Initially arising within the central nervous system, NC cells subsequently undergo an epithelial to mesenchymal transition to migrate into the periphery, where they differentiate into diverse cell types. Here we provide evidence that postnatal human epidermal keratinocytes, in response to FGF2 and IGF1 signals, can be reprogrammed toward a neural crest fate. Genome-wide transcriptome analyses show that keratinocyte-derived NC cells are similar to those derived from human embryonic stem cells. Moreover, they give rise in vitro and in vivo to neural crest derivatives such as peripheral neurons, melanocytes, Schwann cells and mesenchymal cells (osteocytes, chondrocytes, adipocytes and smooth muscle). By demonstrating that human KRT14+ keratinocytes can form neural crest cells, even from clones of single cells, our results have important implications in stem cell biology and regenerative medicine. Overall design: mRNA profiles of KC and KC derived NC (from 3 biological replicates) were generated by deep sequencing using Illumina HiSeq 2500 platform (pair-end (2x50 bp) rapid run mode).
Reprogramming Postnatal Human Epidermal Keratinocytes Toward Functional Neural Crest Fates.
No sample metadata fields
View SamplesIndividuals with cystic fibrosis (CF) experience elevated inflammation in multiple organs, but whether this reflects an inherent feature of CF cells or is a consequence of a pro-inflammatory environment is not clear. Using CRISPR/Cas9-mediated mutagenesis of CFTR, 17 subclonal cell lines were generated from Caco-2 cells. Clonal lines with functional CFTR (CFTR+) were compared to those without (CFTR-) to directly address the role of CFTR in inflammatory gene regulation. All lines maintained CFTR mRNA production and formation of tight junctions. CFTR+ lines displayed short circuit currents in response to forskolin, while the CFTR- lines did not. Baseline expression of both cytokines was not different between the lines regardless of CFTR genotype. All lines responded to TNFa and IL1b by increasing IL6 and CXCL8 (IL8) mRNA levels, but the CFTR- lines produced more CXCL8 mRNA than the CFTR+ lines. Transcriptomes of 6 CFTR- and 6 CFTR+ lines, before and after stimulation by TNFa, were compared for differential expression as a function of CFTR genotype. While some genes appeared to be differentially expressed simply because of CFTR's absence, others required stimulation for differences to be apparent. Together, these data suggest cells respond to CFTR's absence by modulating transcriptional networks, some of which are only apparent when cells are exposed to different environmental contexts, such as inflammation. With regards to inflammation, these data suggest a model in which CFTR's absence leads to a poised, pro-inflammatory state of cells that is only revealed by stimulation. Overall design: Compare cells with intact CFTR to cells lacking CFTR for overall gene expression under basal and TNFa-stimulated conditions
Inactivation of CFTR by CRISPR/Cas9 alters transcriptional regulation of inflammatory pathways and other networks.
Specimen part, Treatment, Subject
View SamplesTo identify gene expression that distinguishes hematopoietic cells that express PRAME from those that do not, normal CD34+ cells with forced PRAME expression were compared to cells without PRAME expression in culture over time (days 4, 7, 14) using Affymetrix HU-133A microarrays
The preferentially expressed antigen in melanoma (PRAME) inhibits myeloid differentiation in normal hematopoietic and leukemic progenitor cells.
Specimen part, Time
View SamplesMesenchymal stem cell-derived extracellular vesicles (EVs) have been shown to promote angiogenesis in the ischemic myocardium. This study examines the difference in vascular density, myocardial perfusion, molecular signaling, and gene expression between normal diet (ND) and high fat diet (HFD) groups at baseline and following intra-myocardial injection of EVs
Effects of High Fat Versus Normal Diet on Extracellular Vesicle-Induced Angiogenesis in a Swine Model of Chronic Myocardial Ischemia.
Sex, Specimen part, Treatment
View Samples