Oxidative and Cytokinin treatment of Arabidopsis wildtype, crf6 mutant, and CRF6 overexpressing seedlings
Cytokinin Response Factor 6 Represses Cytokinin-Associated Genes during Oxidative Stress.
Age
View SamplesIntragenic microRNAs (miRNAs), including both intronic and exonic miRNAs, accounting approximately 50% of total mammalian miRNAs. Previous studies showed that intragenic miRNAs are often co-expressed with their host genes, and thus it was believed that intragenic miRNAs and their host genes are derived from the same primary transcripts. However, we provide evidence to show here that the observations from previous studies might be biased due to the small number and the predominance of "broadly conserved" intronic miRNAs they studied.
Young intragenic miRNAs are less coexpressed with host genes than old ones: implications of miRNA-host gene coevolution.
Disease, Disease stage, Cell line
View SamplesBacillus anthracis is a gram-positive, aerobic, spore-forming, rod-shaped bacterium which has recently been used as an agent of bioterrorism. Because there is a significant delay between the initial contact of the spore with the host and clinical evidence of disease, there appears to be temporary containment of the pathogen by the innate immune system. Contact with the human alveolar macrophage (HAM) plays a key role in the innate immune response to B. anthracis spores. Therefore, the early macrophage response to anthrax exposure is important in understanding the pathogenesis of this disease. The majority of genes modulated by spores were upregulated, and a lesser number were downregulated. The data was subjected to Ingenuity Pathway analysis, the Database for Annotation, Visualization and Integrated Discovery (DAVID) analysis, and the Promoter Analysis and Interaction Network Toolset (PAINT). Among the upregulated genes, we identified a group of chemokine ligands, apoptosis genes and, interestingly, keratin filament genes. Central hubs regulating the activated genes were TNF-alpha, NF-B and their ligands/receptors. Other activated genes included IL-1alpha and IL-18. RNA for these, and several additional cytokines including IL-6, IL-1gamma, IP-10 and GM-CSF, were differentially expressed from 1.6- to 27-fold. The microarray cytokine data is consistent with our previously published findings which demonstrated that there was 4- to 43-fold induction of these cytokines at the transcriptional and translational levels as determined by RNase protection assays and ELISA. The PAINT analysis revealed that the majority of the genes affected by spores contain the binding site for c-Rel, a member of the NF-B family of transcription factors. Other transcription regulatory elements contained in many of the upregulated genes were c-Myb, CP2, Barbie Box, E2F and CRE-BP1. This study is the first detailed microarray analysis to describe the HAM response to B. anthracis.
Gene expression profiling of human alveolar macrophages infected by B. anthracis spores demonstrates TNF-alpha and NF-kappab are key components of the innate immune response to the pathogen.
No sample metadata fields
View SamplesOverexpression of the AP-2 transcription factor in breast tumours has been identified as an independent predictor of poor outcome and failure of hormone therapy, even in ER positive, ErbB2 negative tumours; markers of a more favourable prognosis. To understand further the role of AP-2 in breast carcinoma, we have used an RNA interference and gene expression profiling strategy using the MCF-7 cell line as a model for ER positive, ErbB2 negative tumours with AP-2 overexpression.
AP-2gamma promotes proliferation in breast tumour cells by direct repression of the CDKN1A gene.
Cell line
View SamplesWe performed a factorial experiment examining the effects of calorie restriction (CR) and exercise (EX) in mice. CR mice received 70% of calories but 100% of all other nutrients compared to AL mice. Food consumption, weight gain, and physical activity levels were recorded for 6 weeks.
Distinct effects of calorie restriction and exercise on mammary gland gene expression in C57BL/6 mice.
No sample metadata fields
View SamplesWe explored the effects of dexamethasone and lenalidomide, individually and in combination, on the differentiation of primary human bone marrow progenitor cells in vitro. Both agents promote erythropoiesis, increasing the absolute number of erythroid cells produced from normal CD34+ cells and from CD34+ cells with the types of ribosome dysfunction found in DBA and del(5q) MDS. However, the drugs had distinct effects on the production of erythroid progenitor colonies; dexamethasone selectively increased the number burst-forming units-erythroid (BFU-E), while lenalidomide specifically increased colony-forming units-erythroid (CFU-E). Use of the drugs in combination demonstrates that their effects are not redundant.
Dexamethasone and lenalidomide have distinct functional effects on erythropoiesis.
Specimen part, Treatment
View SamplesBACKGROUND. Human prostate cancer LNCaP and PC-3 cell lines have been extensively used as prostate cancer cell models to study prostate cancer progression and to develop therapeutic agents. Although LNCaP and PC-3 cells are generally assumed to represent early and late stages of prostate cancer development, respectively, there is limited information regarding comprehensive gene expression patterns between these two cells lines and relating these cells to prostate cancer progression based on their gene expression.
Unique patterns of molecular profiling between human prostate cancer LNCaP and PC-3 cells.
No sample metadata fields
View SamplesOur analysis of the sfr6 freezing-sensitive mutant (Knight, H., Veale, E., Warren, G. J. and Knight, M. R. (1999). Plant Cell 11, 875-886.) and cls8 (unpublished) chilling-sensitive mutant of Arabidopsis, has revealed that the expression of certain cold-regulated genes is aberrant in both these mutants. In order to understand the molecular basis of chilling and freezing stress in Arabidopsis and also to determine commonalities and differences between these 2 different physiological stress-tolerance processes, we request transcriptome analysis for both of these mutants compared to wild type in one experiment, upon cold treatment and at ambient conditions. The sfr6 mutant shows the most severe phenotype with respect to cold gene expression, but is tolerant to chilling (Knight, H., Veale, E., Warren, G. J. and Knight, M. R. (1999). Plant Cell 11, 875-886.). However, it is unable to cold acclimate and hence is sensitive to freezing. The cls8 mutant, on the other hand, has a relatively mild phenotype relative to the cold-regulated genes we have examined, but is very sensitive to chilling temperatures (15 to 10 degree centigrade). It is thus likely that in cls8 we have not yet identified the genes which are most affected, and which account for the physiological phenotype. Both sfr6 and cls8 have been fine-mapped and are close to being cloned. The cls8 mutant has an altered calcium signature in response to cold which means it is likely to be affected in early signalling, e.g. cold perception itself.We will compare the expression profiles of genes in sfr6, cls8 and Columbia (parental line for both mutants), both at ambient, and after treatment with cold (5 degrees) for 3 hours. This timepoint is designed to capture both rapidly responding genes e.g. CBF/DREB1 transcription factors, and also more slow genes e.g. COR genes (KIN1/2 and LTI78). Pilot northerns confirm that this time point is suitable.This analysis will provide new insight into 2 novel genes required for tolerance to low temperature in Arabidopsis, and additionally will determine the nature of overlap between the separate processes of chilling and freezing tolerance.
The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.
Specimen part
View SamplesThe sfr6-1 mutant of Arabidopsis has been shown to be defective in freezing tolerance and fails to express a number of cold-regulated genes to normal wild type levels. The aim of this experiment was to test whether two other mutant alleles, sfr6-2 and sfr6-3 showed similar defects in cold-inducible gene expression.
The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.
Age
View SamplesA major problem in cancer research is the lack of a tractable model for delayed metastasis. Herein we show that cancer cells suppressed by SISgel, a gel-forming normal ECM material derived from Small Intestine Submucosa (SIS), in flank xenografts show properties of suppression and re-activation that are very similar to normal delayed metastasis and suggest these suppressed cells can serve as a novel model for developing therapeutics to target micrometastases or suppressed cancer cells. Co-injection with SISgel suppressed the malignant phenotype of highly invasive J82 bladder cancer cells and highly metastatic JB-V bladder cancer cells in nude mouse flank xenografts. Cells could remain viable up to 120 days without forming tumors and appeared much more highly differentiated and less atypical than tumors from cells co-injected with Matrigel. In 40% of SISgel xenografts, growth resumed in the malignant phenotype after a period of suppression or dormancy for at least 30 days and was more likely with implantation of 3 million or more cells. Ordinary Type I collagen did not suppress malignant growth, and tumors developed about as well with collagen as with Matrigel. A clear signal in gene expression over different cell lines was not seen by transcriptome microarray analysis, but in contrast, Reverse Phase Protein Analysis of 250 proteins across 4 cell lines identified Integrin Linked Kinase (ILK) signaling that was functionally confirmed by an ILK inhibitor. We suggest that cancer cells suppressed on SISgel could serve as a model for dormancy and re-awakening to allow for the identification of therapeutic targets for treating micrometastases.
Suppression and activation of the malignant phenotype by extracellular matrix in xenograft models of bladder cancer: a model for tumor cell "dormancy".
Cell line
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