Project description:Changes in human bladder epithelial cell gene expression associated with interstitial cystitis or antiproliferative factor treatment. Explanted bladder epithelial cells from patients with interstitial cystitis (IC) have been shown to differ from explanted control cells in several ways, including production of an antiproliferative factor (APF), altered production of certain epithelial growth factors, and rate of proliferation. To better understand the role of the APF in abnormal bladder epithelial cell proliferation in IC, we studied gene expression patterns in normal bladder epithelial cells treated with APF vs. mock APF and compared them to expression patterns in IC vs. normal cells using microarray analysis. Oligo-dT-primed total cellular RNA was labeled with [33P]dCTP and hybridized to GeneFilter GF211 microarray membranes (Research Genetics) containing cDNA for 3,964 human genes. Thirteen genes that function in epithelial cell proliferation or differentiation were consistently differentially expressed in both IC (compared with control) and APF-treated (compared with mock APF-treated) normal bladder epithelial cells. The general pattern of gene expression in IC and APF-treated cells suggested a less proliferative phenotype, with increased expression of E-cadherin, phosphoribosylpyrophosphate synthetase-associated protein 39, and SWI/SNF complex 170-kDa subunit, and decreased expression of vimentin, {alpha}2-integrin, {alpha}1-catenin, cyclin D1, and jun N-terminal kinase 1; these findings were confirmed for the structural gene products (E-cadherin, vimentin, {alpha}2-integrin, and {alpha}-catenin) by immunohistochemistry. These results are compatible with the previously noted decreased proliferation rate of IC and APF-treated normal cells, and indicate that the mechanism whereby APF inhibits cell proliferation may involve both downregulation of genes that stimulate cell proliferation along with upregulation of genes that inhibit cell growth.
Project description:The stringent response was defined in Lactococcus lactis through transcript profiling after the addition of a chemical inductor, the norvaline. Gene expression was measured in the exponential growth phase (reference sample) and at 1.6 h after norvaline addition. Four hundred and sixty one differentially expressed genes were identified and constituted the stringent response regulon. Keywords: stress response, time course Stringent response was imposed through norvaline addition during the growth of Lactococcus lactis IL1403 under controlled conditions (30 °C, pH 6.6, nitrogen atmosphere). Cell samples were harvested in exponential phase and 1.6 h after norvaline addition. Total RNA was extracted from these samples and radiolabelled cDNA were prepared and hybridized on nylon arrays. 2053 amplicons specific of Lactococcus lactis IL1403 genes were spotted twice on the array. The 2 time-points were analyzed simultaneously and 3 independent repetitions were performed.
Project description:Changes in gene expression after treatment of E. coli cultures with mitomycin C were assessed using gene array technology. Unexpectedly, a large number of genes (nearly 30% of all genes) displayed significant changes in their expression level. Analysis and classification of expression profiles of the corresponding genes allowed us to assign this large number of genes into a dozen to two dozen small clusters of genes with similar expression profiles. This assignment allowed us to describe systematically the changes in the level of gene expression in response to DNA damage. Among the damage-induced genes more than a hundred are novel. From those genes involved in DNA metabolism that have not been previously shown to be induced by DNA damage, for example, the mutS gene involved in mismatch repair is especially noteworthy. In addition to the SOS response, we observed the induction of other stress response pathways such as those of oxidative stress and osmotic protection. Among the genes that are down-regulated in response to DNA damage are numerous protein biosynthesis genes. Analysis of the gene expression data highlighted the essential involvement of sigmaS regulated genes and the general stress response network in the response to DNA damage. Keywords = DNA damage, recA, SOS
Project description:Gastrointestinal stromal tumors (GIST) are phenotypically and clinically heterogeneous mesenchymal tumors. Using the cDNA array technique, we analyzed the gene expression profiles of 22 GIST and 7 non-neoplastic gastrointestinal smooth muscle specimens, in order to detect molecular differences between GIST and non-neoplastic tissue, and to detect differences between GIST of various phenotypic and clinical subgroups. As a result, we found 796 differentially expressed genes and ESTs between GIST and smooth muscle tissue, including promising new candidate genes for the pathogenesis of GIST. Furthermore, we identified differences in gene expression between GIST of different site, size, and immunohistochemical expression of CD34 and SMA. Our data show that alterations in gene expression are associated with morphologically and clinically detectable features of GIST and provide new aspects for the understanding of these tumors. Keywords = Gastrointestinal Stromal Tumor (GIST)
Project description:Contains a row for each intergenic cluster in each sample, indicating whether our analysis called the cluster "present" or "absent" in the sample. Intergenic clusters are novel (unannotated) genes detected by aligning Arabidopsis cDNAs/ESTs to the genome. Cluster coordinates refer to version 3 of the TIGR annotation as submitted to GenBank (GI numbers 22330780, 22326553, 22331929, 22329272, 22328163).
Project description:Contains a row for each annotated gene in each sample, indicating whether our analysis called the gene "present" or "absent" in the sample. Gene names and coordinates refer to version 3 of the TIGR annotation as submitted to GenBank (GI numbers 22330780, 22326553, 22331929, 22329272, 22328163).
Project description:Contains a row for each annotated gene in each sample, indicating whether our analysis called the region antisense to the coding region of the gene "present" or "absent" in the sample. Gene names and coordinates refer to version 3 of the TIGR annotation as submitted to GenBank (GI numbers 22330780, 22326553, 22331929, 22329272, 22328163).
Project description:Contains a row for each intergenic region in each sample, indicating whether our analysis called a window within the region "present" or "absent" in the sample. Intergenic regions are regions containing neither annotated genes nor intergenic clusters. Region coordinates refer to version 3 of the TIGR annotation as submitted to GenBank (GI numbers 22330780, 22326553, 22331929, 22329272, 22328163).
Project description:The development of transcriptomic tools has allowed exhaustive description of stress responses. These responses always superimpose a general response associated to growth rate decrease and a specific one corresponding to the stress. The exclusive growth rate response can be achieved through chemostat cultivation, enabling all parameters to remain constant except the growth rate. We analysed metabolic and transcriptomic responses of Lactococcus lactis in continuous cultures at different growth rates ranging from 0.09 to 0.47 h-1. Growth rate was conditioned by isoleucine supply. Although the metabolism was constant and homolactic, a widespread transcriptomic response involving 30 % of the genome was observed. The expression of genes encoding physiological functions associated with biogenesis increased with growth rate (transcription, translation, fatty acid and phospholipids metabolism). Many phages, prophages and transposons related genes were down regulated by growth rate suggesting genome plasticity to be involved in the adaptation to slow growth. The growth rate response was compared to carbon and amino-acid starvation transcriptomic responses, revealing constant and significant involvement of growth rate regulations in these two stressful conditions (overlap 26%). Although stringent response mechanism is considered as the one governing growth deceleration in bacteria, the rigorous comparison of the two transcriptomic responses clearly indicated the mechanisms are distinct. Moreover it was established that genes positively regulated by growth rate are preferentially located in the vicinity of replication origin while those negatively regulated are mainly encountered at the opposite. This result demonstrates the often neglected relationship between genes expression and their location on chromosome. Keywords: growth rate impact, continuous cultures Continuous cultivation of Lactococcus lactis IL1403 were carried out on a chemically defined medium and under controlled conditions (30 °C, pH 6.6, nitrogen atmosphere). Cell samples were harvested at steady state. Total RNA was extracted from these samples and radiolabelled cDNA were prepared and hybridized on nylon arrays. 1948 amplicons specific of Lactococcus lactis IL1403 genes were spotted twice on the array. Samples corresponding to various growth rates were analyzed simultaneously and 3 independent repetitions were performed.