Project description:Expression of HIF-1a or Twist1 or Bmi1 in human hypopharyngeal cancer cell line FADU results in the drift of transcriptome profile from an epithelial cell-like signature to a mesenchymal stem cell-like signature. Stable transfection of pHA-HIF1a(dODD), pFLAG-Twist1 or pcDNA3-Bmi1 in FADU cell and analyzed the transcriptome by cDNA microarray. FADU transfected with pcDNA3.1 empty vector was used as a control of experiment.
Project description:Tumor microenvironments present significant barriers to anti-tumor agents. Molecules involved in multicellular tumor microenvironments, however, are difficult to study ex vivo. Here, we generated a matrix-free tumor spheroid model using the NCI-H226 mesothelioma cell line and compared the gene expression profiles of spheroids and monolayers using microarray analysis. Microarray analysis revealed that 142 probe sets were differentially expressed between tumor spheroids and monolayers. Gene ontology analysis revealed that upregulated genes were primarily related to immune response, wound response, lymphocyte stimulation and response to cytokine stimulation, whereas downregulated genes were primarily associated with apoptosis. Among the 142 genes, 27 are located in the membrane and related to biologic processes of cellular movement, cell-to-cell signaling, cellular growth and proliferation and morphology. Western blot analysis validated elevation of MMP2, BAFF/BLyS/TNFSF13B, RANTES/CCL5 and TNFAIP6/TSG-6 protein expression in spheroids as compared to monolayers. Thus, we have reported the first large scale comparison of the transcriptional profiles using an ex vivo matrix-free spheroid model to identify genes specific to the three-dimensional biological structure of tumors. The method described here can be used for gene expression profiling of tumors other than mesothelioma. We generated a matrix-free tumor spheroid model using the NCI-H226 mesothelioma cell line and compared the gene expression profiles of spheroids and monolayers using microarray analysis. Microarray analysis experiments were performed in triplicates. A total of six samples (three for monolayers and three for spheroids) were analyzed.
Project description:Expression of let-7i results in transcriptome alteractions in head and neck cancer cell line, OECM1. Stable transfection of pmCherry-let7i in OECM1 cell and analyzed the transcriptome by cDNA microarray. OECM1 transfected with pmCherry empty vector was used as a control of experiment.
Project description:We explored gene expression profile of human aortic valves in patients with or without aortic stenosis. The dataset that we generated constitutes a large-scale quantitative measurements of gene expression in normal and stenotic human valves. The goal was to compare gene expression levels between the two groups and identified a list of genes that are up- or down-regulated in aortic stenosis. Keywords: disease state analysis Gene expression was performed on ten normal and ten aortic stenosis valves
Project description:Comparison of wild type S. flexneri 2457T gene expression to deletion mutant of S. flexneri 2457T gene S4473 at three growth phases and intracellularly Broth culture was grown to mid-log in LB, intracellular growth was 3 hours post invasion of HCT-8 cell (colonic epithelial cell line).
Project description:Enterohemorrhagic E. coli (EHEC) colonizes the large intestine and causes attaching and effacing lesions (AE). Most of the genes involved in the formation of AE lesions are encoded within a chromosomal pathogenicity island termed the Locus of Enterocyte Effacement (LEE). The LysR-like transcriptional factor QseA regulates the LEE by binding directly to the regulatory region of ler. Here, we performed transcriptome analyses comparing WT EHEC and the isogenic qseA mutant in order to elucidate the extent of QseA’s role in gene regulation in EHEC. The following results compare genes that were up-regulated and down-regulated ! 2-fold in the qseA mutant strain compared to the WT strain. At mid-exponential growth, 222 genes were up-regulated and 1874 were downregulated. At late-exponential growth, a total of 55 genes were up-regulated and 605 genes were down-regulated. During mid-exponential growth, QseA represses its own transcription, whereas during late-logarithmic growth, QseA activates expression of the LEE genes as well as non-LEE encoded effector proteins. During both growth phases, several genes carried in O-islands, were activated by QseA, whereas genes involved in cell metabolism were repressed. We also performed electrophoretic mobility shift assays, competition experiments, and DNAseI footprints, and the results suggested that QseA directly binds both the ler proximal and distal promoters, its own promoter, as well as promoters of genes encoded in EHEC-specific O-islands. Additionally, we mapped the transcriptional start site of qseA, leading to the identification of two promoter sequences. Taken together, these results indicate that QseA acts as a global regulator in EHEC, coordinating expression of virulence genes. Design of the study was to make the knockout of the qseA gene and compare the transcriptional response to that and the wild type.
Project description:Osteoblasts are key players in bone remodeling. The accessibility of human primary osteoblast-like cells (HOb) from bone explants render them a lucrative model for studying molecular physiology of bone turnover, discovery of novel anabolic therapeutics and mesenchymal cell biology in general. Relatively little is known about resting and dynamic expression profiles of HObs and no studies have been conducted to date to systematically assess the osteoblast transcriptome. The aim of this study was to characterize HObs and investigate signaling cascades and gene networks using genomewide expression profiling in resting and Bone Morphogenic Protein (BMP)-2 and Dexamethasone induced cells. Our data showed a vast number of genes and networks expressed predominantly in HObs as compared to closely related cells such as fibroblasts or chondrocytes. For instance, genes in the insulin-like growth factor (IGF) signaling pathway were enriched in HObs (p=0.003) and included the binding proteins (IGFBP1, 2, 5) and IGF-2 and its receptor. Another HOb specific expression pattern included leptin and its receptor (p<10-8). Furthermore, after stimulating HObs with Dexamethasone or BMP-2, the expression of several interesting genes and pathways were observed where data supported the role of peripheral leptin signaling in bone cell function. In conclusion, we provide the landscape of tissue-specific and dynamic gene expression in HObs, a resource, which will allow utilization of osteoblasts as a model to study specific gene networks and gene families related to human bone physiology and diseases. Experiment Overall Design: Human trabecular bone from the proximal femoral shaft was collected from two male patients, both undergoing total hip replacement. The bone chips were minced thoroughly and washed with PBS and cultured in three biological replicates in cell medium containing alpha-MEM supplemented with 2 mmol/l L-Glutamine, 100U/mL penicillin, 100mg/mL streptomycin, and 10% fetal bovine serum and grown at 37 degreeC with 5% CO2 until confluence. At 70-80% confluence, each replicate was trypsinized and sub-cultured in 6-well plates (100 000 cells/well) for 12 days. Prior to treatment, the cells were starved for 20h by adding complete cell medium containing 0.5% fetal bovine serum. The cells were then incubated for 2h and 24h with 10-7 M of dexamethasone and 10-4 mg/ml of rhBMP-2 with the same concentration of vehicle, respectively. Experiment Overall Design: At the two time points, the cell medium was removed and the cells were harvested stored in -70 degreeC until RNA extraction. Experiment Overall Design: RNA was isolated from the cell lysates using the RNeasy Mini Kit and Experiment Overall Design: expression studies were performed in triplicate (biological replicates) using the Affymetrix Human Genome U133 plus 2.0 Array (Affymetrix, Santa Clara, CA, USA). One microgram of RNA was reverse transcribed into cDNA and in vitro transcription was performed to generate biotin-labeled cRNA for subsequent hybridization. Hybridized target cRNA was then stained with streptavidin phycoerythrin, and arrays were scanned using a GeneArray Scanner at an excitation wavelength of 488nm.
Project description:Escherichia coli O157:H7 is a food-borne pathogen that causes bloody diarrhea and hemolytic uremic syndrome. Hfq is an sRNA chaperone protein that is involved in post-transcriptional regulation of virulence genes in pathogenic bacteria. In EHEC strain EDL933, Hfq acts a negative regulator of the locus of enterocyte effacement (LEE) that encodes most of the proteins involved in type three secretion and attaching and effacing lesions. We deleted hfq in E. coli O157:H7 strain 86-24 and compared global transcription profiles of the hfq mutant to the wild type strain in exponential growth phase. Deletion of hfq affected transcription of genes common to nonpathogenic and pathogenic strains of E. coli as well as pathogen-specific genes. Downregulated genes in the hfq mutant included ler as well as genes encoded in LEE2-5 that encode for type three secretion and AE lesion formation. Decreased expression of the LEE genes in the hfq mutant occurred at mid-, late, and stationary growth phases in both LB and DMEM media as detected by qRT-PCR. We also confirmed decreased regulation of the LEE genes by examining secreted proteins and AE lesion formation by the hfq mutant and WT strains. Deletion of hfq also caused decreased expression of the two-component system qseBC involved in inter-kingdom signaling and virulence gene regulation in EHEC as well as an increase in stx2AB expression that encodes for the deadly Shiga toxin. Altogether, these data indicate that Hfq plays a different regulatory role in EHEC 86-24 from what has been reported for EHEC strain EDL933 and that the role of Hfq in EHEC virulence regulation extends beyond the LEE. Comparison of transcriptional regulation of the WT 86-24 isolate and the hfq mutant for the identification of regulated targets that were followed up by functional analysis.