Our earlier study demonstrated that when CFSE-labeled LCMV-or Pichinde virus-immune spleen leukocytes were transferred into T cell-deficient hosts, the bona fide virus-specific memory cells underwent relatively limited cell division and were substantially diluted in frequency by other more extensively proliferating cells originating from that donor cell population. We questioned how the slowly dividing population, which contained bona fide memory cells, differed from the rapidly dividing cells, which contained memory-like cells. As a preliminary screen we performed a comparative genome-wide microarray analysis of genes expressed on sorted rapidly proliferating (CFSE-low) and slowly proliferating (CFSE-high) CD8 cell populations
Programmed death-1 (PD-1) defines a transient and dysfunctional oligoclonal T cell population in acute homeostatic proliferation.
Age, Specimen part
View SamplesComparison of rosette leaves of two different RAP2.2 overexpressing lines with wild type leaves. The AP2/EREBP transcription factor RAP2.2 was shown to bind to a cis-acting motif within the phytoene synthase promoter from Arabidopsis. To investigate effects of increased RAP2.2 levels, two RAP2.2 overexpressing Arabidopsis thaliana (ecotype Wassilewskija) lines were generated: one line, nosr2, carried the nos promoter and showed a two-fold increase in RAP2.2 transcript level, the second line, cmr-5, carried four copies of the CaMV-35S enhancer and showed a 12-fold increase. However, neither weak nor strong increase in RAP2.2 transcript amounts had any effect on RAP2.2 protein levels as shown by Western blot analysis. The strong robustness of RAP2.2 protein levels towards transcriptional changes can be explained by specific protein degradation which includes SINAT2, an E3 ubiquitin ligase which was isolated using a two-hybrid approach. Accordingly, global gene expression analysis using both RAP2.2 overexpressing lines showed only minor transcriptional changes which are probably due to minor growth variation than to mechanisms involved in the down-regulation of RAP2.2 protein amounts.
Transcription factor RAP2.2 and its interacting partner SINAT2: stable elements in the carotenogenesis of Arabidopsis leaves.
Specimen part
View SamplesElevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
No sample metadata fields
View SamplesThe Her-2/Neu-positive mouse breast cancer cell line was serially co-cultured with minced brain, bone marrow, and lung tissue in an intravital microscopy chamber mounted on the dorsal skinfold of nude mice, alternating with growth in vitro. Gene expression analysis was performed on the cells grown in culture after sorting and further growth in vitro. Gene expression under these growth conditions differed in time and according to the co-cultivated organ tissue. This study reveals genes that are expressed by cells as they adapt differentially to various foreign tissue microenvironments, and may represent a paradigm to discover gene expression changes that occur immediately upon extravasation when cancer metastasizes.
Effects of different tissue microenvironments on gene expression in breast cancer cells.
Cell line
View SamplesElevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
No sample metadata fields
View SamplesThe mineralocorticoid aldosterone mainly produced by the adrenal gland is essential for life but an abnormal excessive secretion causes severe pathological effects including hypertension and target organ injury in the heart and kidney. The aim of this study was to determine the gene regulatory network triggered by aldosterone secretagogues in a non transformed cell system. Freshly isolated rat adrenal zona glomerulosa cells were stimulated with the two main aldosterone secretagogues, angiotensin II and potassium, for two hours and subjected to whole genome expression studies using multiple biological and bioinformatics tools. Several genes were differentially expressed by Ang II (n=133) or potassium (n=216). Genes belonging to the nucleic acid binding and transcription factor activity categories were significantly enriched. A subset of the most regulated genes were confirmed by real-time RT-PCR and then their expression analyzed in time curve studies. Differentially expressed genes were grouped according to their time-response expression pattern and their promoter regions analyzed for common regulatory transcription factors binding sites. Finally, data mining with gene promoters, transcription factors and literature databases were performed to generate gene interaction networks for either Ang II or potassium. This study provides for the first time a complete study of the genes that are regulated, and the interaction between them, by aldosterone secretagogues in rat adrenal cells. Increasing our knowledge of adrenal physiology and gene regulation in non transformed cell systems would lead us to a better approach for discovery of candidate genes involved pathological conditions of the adrenal cortex.
Gene expression profile in rat adrenal zona glomerulosa cells stimulated with aldosterone secretagogues.
No sample metadata fields
View SamplesMycobacterium bovis (M. bovis) and Mycobacterium avium subspecies paratuberculosis (MAP) are important pathogens of cattle, causing bovine tuberculosis and Johne's disease respectively. M. bovis and MAP infect residential macrophages in the lung and intestines respectively and subvert the macrophage biology to create a survival niche. To investigate this interaction we simultaneously studied the transcriptional response of bovine monocyte-derived macrophages to infection with two strains of M. bovis (AF2122/97 and G18) and two strains of MAP (C & L1). Overall design: 120 samples were analysed in total; derived from six biological replicates (i.e. cells isolated from six cattle). Cells were left uninfected (medium only controls) or infected with either a M. bovis strain (AF2122/97 or G18) or a MAP strain (C or L1). Cells were harvested at 2, 6, 24 and 48h post infection.
Variation in the Early Host-Pathogen Interaction of Bovine Macrophages with Divergent Mycobacterium bovis Strains in the United Kingdom.
Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genomic responses from the estrogen-responsive element-dependent signaling pathway mediated by estrogen receptor alpha are required to elicit cellular alterations.
No sample metadata fields
View SamplesIn addition to the estrogen responsive element (ERE)-dependent gene expression, E2-ERbeta regulates transcription through functional interactions with transfactors bound to their cognate regulatory elements on DNA, hence the ERE-independent signaling pathway. However, the relative importance of the ERE-independent pathway in E2-ERbeta signaling is unclear. Our studies in infected ER-negative cell models with an ERbeta mutant (ERbetaDBD) that functions exclusively at the ERE-independent pathway demonstrated that genomic responses assessed by microarrays from the ERE-independent pathway to E2-ERbeta are not sufficient to alter cellular growth, death or motility. These findings suggest that the ERE-dependent pathway is the canonical E2-ERbeta signaling in model cell lines.
Genomic responses from the estrogen-responsive element-dependent signaling pathway mediated by estrogen receptor alpha are required to elicit cellular alterations.
No sample metadata fields
View SamplesIn addition to the estrogen responsive element (ERE)-dependent gene expression, E2-ERalpha regulates transcription through functional interactions with transfactors bound to their cognate regulatory elements on DNA, hence the ERE-independent signaling pathway. However, the relative importance of the ERE-independent pathway in E2-ERalpha signaling is unclear. Our studies in infected ER-negative cell models with an ERalpha mutant (ERalpha 203/204/211E) that functions exclusively at the ERE-independent pathway demonstrated that genomic responses assessed by microarrays from the ERE-independent pathway to E2-ERalpha are not sufficient to alter cellular growth, death or motility. These findings suggest that the ERE-dependent pathway is the canonical E2-ERalpha signaling in model cell lines.
Genomic responses from the estrogen-responsive element-dependent signaling pathway mediated by estrogen receptor alpha are required to elicit cellular alterations.
No sample metadata fields
View Samples