Project description:A promising treatment for patients with advanced colorectal cancer is preoperative radiochemotherapy. The early side effects of this treatment have been considered to be acceptable. The aim of this study was to identify the effects of preoperative radiochemotherapy (PRT) on gene expression in tumour and normal colon rectal tissue form the same patients, before and after PRT. For that purpose, tissue samples from ten patients with operable rectal adenocarcinomas were collected for use in whole genomeâmicroarray based gene expression analysis. A factorial experimental design allowed us to look solely at the radiation effect on tumours. This resulted in 4496 differentially expressed genes in tumour tissue with p<0.05. In addition to known markers for radiochemotherapy, a Gene Set Enrichment Analysis (GSEA) showed a significant enrichment in gene sets associated with cell adhesion and leukocyte transendothelial migration (TEM). We conclude that radiochemotherapy has a greater effect in tumour tissue gene expression than normal tissue. Not only is the effect on normal tissue limited compared to tumour, but significantly different gene sets are enriched. The profound change of cell adhesion molecule expression in tumour tissue could either increase the risk of metastasis, or decrease the tumours invasive potential. Further characterization of genes involved in cell adhesion and leukocyte TEM may give new insights into the molecular responses to radiochemotherapy in colorectal cancer. Factorial experimental design
Project description:A promising treatment for patients with advanced colorectal cancer is preoperative radiochemotherapy. The early side effects of this treatment have been considered to be acceptable. The aim of this study was to identify the effects of preoperative radiochemotherapy (PRT) on gene expression in tumour and normal colon rectal tissue form the same patients, before and after PRT. For that purpose, tissue samples from ten patients with operable rectal adenocarcinomas were collected for use in whole genome–microarray based gene expression analysis. A factorial experimental design allowed us to look solely at the radiation effect on tumours. This resulted in 4496 differentially expressed genes in tumour tissue with p<0.05. In addition to known markers for radiochemotherapy, a Gene Set Enrichment Analysis (GSEA) showed a significant enrichment in gene sets associated with cell adhesion and leukocyte transendothelial migration (TEM). We conclude that radiochemotherapy has a greater effect in tumour tissue gene expression than normal tissue. Not only is the effect on normal tissue limited compared to tumour, but significantly different gene sets are enriched. The profound change of cell adhesion molecule expression in tumour tissue could either increase the risk of metastasis, or decrease the tumours invasive potential. Further characterization of genes involved in cell adhesion and leukocyte TEM may give new insights into the molecular responses to radiochemotherapy in colorectal cancer.
Project description:Asthma is a chronic inflammatory airway disease characterized by airway inflammation and remodeling. The role of 15-oxo-5Z,8Z,11Z,13E-eicosatetraenoic acid (15-oxoETE), a 15-HETE metabolite catalyzed by 15-prostaglandin dehydrogenase (15-PGDH), has been relatively unexplored in asthma. In this study, we used RNA-seq to explore the effect of 15-KETE on the transcriptome of airway epithelial cells, aiming to identify its potential downstream targets and mechanisms of action.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:41 lung adenocarcinoma from never-smokers hybridized on Illumina SNP arrays on 13 HumanCNV370-Quadv3 chips. High-resolution array comparative genomic hybridization analysis of lung adenocarcinoma in 41 never smokers for identification of new minimal common regions (MCR) of gain or loss. The SNP array analysis validated copy-number aberrations and revealed that RB1 and WRN were altered by recurrent copy-neutral loss of heterozygosity.The present study has uncovered new aberrations containing cancer genes. The oncogene FUS is a candidate gene in the 16p region that is frequently gained in never smokers. Multiple genetic pathways defined by gains of MYC, deletions of RB1 and WRN or gains on 7p and 7q are involved in lung adenocarcinoma in never smokers. A 'Cartes d'Identite des Tumeurs' (CIT) project from the French National League Against Cancer (http://cit.ligue-cancer.net) 41 samples hybridized on Illumina SNP arrays. Submitter : Fabien PETEL petelf@ligue-cancer.net . Project leader : Pr Pierre FOURET pierre.fouret@psl.aphp.fr
Project description:SPO11-promoted DNA double-strand breaks (DSBs) formation is a crucial step for meiotic recombination, and it is indispensable to detect the broken DNA ends accurately for dissecting the molecular mechanisms behind. Here, we report a novel technique, named DEtail-seq (DNA End tailing followed by sequencing), that can directly and quantitatively capture the meiotic DSB 3’ overhang hotspots at single-nucleotide resolution.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.