Combining genome-wide microarray and functional analyses, we found that EGFR activation abrogates barrier function, increasing transepidermal water loss (TEWL) and transepithelial permeability of water-soluble ions and higher molecular weight dextrans, in part by disrupting the expression of tight junction proteins. EGF decreases certain lipid matrix free fatty acids and ceramides by its actions to repress the expression of specific biosynthetic enzymes.
EGFR regulation of epidermal barrier function.
Specimen part
View SamplesTCDD increased expression of numerous differentiation specific genes and decreased expression of numerous genes involved in mitochondrial health and redox homeostasis
2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated production of reactive oxygen species is an essential step in the mechanism of action to accelerate human keratinocyte differentiation.
Specimen part, Cell line
View Samplesp63 is critical for epithelial development yet little is known about the transcriptional programmes it regulates. The p63 transactivating (TA) isoforms contain an amino-terminal exon that encodes a p53-like transactivation domain, whereas N-isoforms lack this domain but contain the common DNA binding domain (DBD), suggesting that TAp63 and Np63 isoforms may have opposing functions. By characterising transcriptional changes and cellular effects following modulation of p63 expression, we have defined a vital role for p63 in cellular adhesion. Knockdown of p63 expression caused downregulation of cell adhesion-associated genes, cell detachment and anoikis in mammary epithelial cells and keratinocytes. Conversely, overexpression of the TAp63 or Np63 isoforms of p63 upregulated cell adhesion molecules, increased cellular adhesion and conferred resistance to anoikis.
p63 regulates an adhesion programme and cell survival in epithelial cells.
Cell line
View SamplesTherapeutic targeting of BRAFV600Eand of MEK has shown a significant impact on progression-free and overall survival in advanced melanoma, but only a fraction of patients benefit from these treatments, suggesting that additional signaling pathways involved in melanoma growth/survival need to be identified. To this end, we used whole genome microarray analysis to identify differentially expressed genes in a set of neoplastic clones, isolated from a single melanoma metastasis, and characterized by mututally exclusive expression of BRAFV600E or NRASQ61R. By this approach we identified two genes, SEMA6A and Mical-1 belonging to the semaphorin-plexin signaling pathway and higly expressed, at mRNA and protein level, in BRAF-mutant neoplastic clones. Real-time PCR, Western blot analysis and immunohistochemistry confirmed the preferential expression of SEMA-6A and Mical-1 in BRAFV600E neoplastic cells from melanoma clones, primary and metastatic cell lines and tissue sections from melanoma lesions. SEMA6A depletion, by specific RNA-interference experiments, led to cytoskeletal remodeling, loss of stress fibers, generation of actin-rich protrusion, and cell death, whereas SEMA6A overexpression, in NRASQ61R clones, promoted invasiveness. Mical-1 depletion, by siRNA, in BRAFV600E melanomas, did not alter the actin cytoskeleton organization but caused a strong NDR phosphorylation and NDR-dependent apoptosis. Overall, these results suggest that the SEMA and MICAL pathways contribute to promote survival of BRAFV600E melanomas.
Sema6A and Mical1 control cell growth and survival of BRAFV600E human melanoma cells.
Cell line
View SamplesPhenotypic heterogeneity has been observed among mesenchymal stem/stromal cell (MSC) populations, but specific genes associated with this variability have not been defined. To study this question, we analyzed two distinct MSC populations isolated from the same umbilical cord blood (UCB) sample. These populations (UCB1 and UCB2) are from a single donor, minimizing differences contributed by genetic background. We characterized these UCB-MSCs for cell morphology, growth kinetics, immunophenotype and differentiation potential. UCB1 displayed rapid growth kinetics, higher population doublings, and increased adipogenic lineage differentiation compared to UCB2. To identify the MSC-specific and developmental genes associated with these phenotypic differences, we performed expression analysis using Affymetrix HG-U133 microarrays and compared them to bone marrow (BM) MSCs. First, hepatocyte growth factor (HGF) and stromal derived factor 1 (SDF1/CXCL12) were up -regulated in UCB1 cells, potentially contributing to the higher growth kinetics observed in this circulating cell population. Second, we observed that peroxisome proliferation activated receptor gamma (PPARG), a marker for adipogenic differentiation, was significantly increased in undifferentiated UCB1 cells. Moreover, significant expression of gene markers of blastocyst and gatrulation embryonic stages were detected in UCB1 and UCB2 cells, as were selected markers of early hematopoiesis, chondrogenesis, and cardiac differentiation. Comparison of UCB1, UCB2, and BM by microarray analysis clearly demonstrated clusters of developmental genes that displayed significant differences among these cells. Quantitative PCR analysis of selected genes validated the microarray results. Comparison of different UCB-derived adherent cells from a single donor has identified gene profiles potentially useful for therapeutic evaluation of MSC populations.
Identification of cord blood-derived mesenchymal stem/stromal cell populations with distinct growth kinetics, differentiation potentials, and gene expression profiles.
Specimen part
View SamplesInterleukin-21 (IL-21) is a pleiotropic cytokine that induces expression of transcription factor BLIMP1 (encoded by Prdm1), which regulates plasma cell differentiation and T cell homeostasis. We identified an IL-21 response element downstream of Prdm1 that binds the transcription factors STAT3 and IRF4, which are required for optimal Prdm1 expression. Genome-wide ChIP-Seq mapping of STAT3- and IRF4-binding sites showed that most regions with IL-21-induced STAT3 binding also bound IRF4 in vivo, and furthermore, revealed that the noncanonical TTCnnnTAA GAS motif critical in Prdm1 was broadly used for STAT3 binding. Comparing genome-wide expression array data to binding sites revealed that most IL-21-regulated genes were associated with combined STAT3-IRF4 sites rather than pure STAT3 sites. Correspondingly, ChIP-Seq analysis of Irf4_/_ T cells showed greatly diminished STAT3 binding after IL-21 treatment, and Irf4_/_ mice showed impaired IL- 21-induced Tfh cell differentiation in vivo. These results reveal broad cooperative gene regulation by STAT3 and IRF4.
Analysis of interleukin-21-induced Prdm1 gene regulation reveals functional cooperation of STAT3 and IRF4 transcription factors.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Up-regulation of expression of the ubiquitin carboxyl-terminal hydrolase L1 gene in human airway epithelium of cigarette smokers.
Sex, Age, Race
View SamplesUpregulation of Expression of the Ubiquitin Carboxyl Terminal Hydrolase L1 Gene in Human Airway Epithelium of Cigarette Smokers
Up-regulation of expression of the ubiquitin carboxyl-terminal hydrolase L1 gene in human airway epithelium of cigarette smokers.
Sex, Age
View SamplesModification of Gene Expression of the Small Airway Epithelium in Response to Cigarette Smoking
Modification of gene expression of the small airway epithelium in response to cigarette smoking.
Sex, Age
View SamplesBCL6 inhibitor induces derepression of BCL6 target genes and shows a similar transcriptional program to BCL6 siRNA Overall design: Genome-wide profiling of mRNA transcript levels in human DLBCL cell line with BCL6 inhibitor and DMSO control.
Rationally designed BCL6 inhibitors target activated B cell diffuse large B cell lymphoma.
Specimen part, Subject
View Samples