Project description:Two expression profilings were conducted in order to identify drug-associated genes in ovarian cancers. The first expression profiling was performed between RNAs from chemosensitive ovarian cancers and chemoresistant ovarian cancers. The second analysis was using a drug sensitive ovarian cancer cell line and a multi-drug resistant ovarian cancer cell line.
Project description:ATRX is a severe X-linked disorder characterized by mental retardation, facial dysmorphism, urogenital abnormalities and alpha-thalassemia. The disease is caused by mutations in ATRX gene, which encodes a protein belonging to the SWI/SNF DNA helicase family, a group of proteins involved in the regulation of gene transcription at the chromatin level. In order to identify specific genes involved in the pathogenesis of the disease, we compared, by cDNA microarray, the expression levels of approximately 8500 transcripts between ATRX and normal males of comparable age. The analysis has been performed on pooled RNA extracted by Peripheral blood mononuclear cell pellet of three male ATRX patients in comparison to that obtained from a pool of 42 normal males (age 7.6+ 2.4).
Project description:Paneth cells of intestinal crypts contribute to host defense by producing antimicrobial peptides that are packaged as granules for secretion into the crypt lumen. Here, we provide evidence using light and electron microscopy that postsecretory Paneth cell granules undergo limited dissolution and accumulate within the intestinal crypts of cystic fibrosis (CF) mice. On the basis of this finding, we evaluated bacterial colonization and expression of two major constituents of Paneth cells, i.e., {alpha}-defensins (cryptdins) and lysozyme, in CF murine intestine. Paneth cell granules accumulated in intestinal crypt lumens in both untreated CF mice with impending intestinal obstruction and in CF mice treated with an osmotic laxative that prevented overt clinical symptoms and mucus accretion. Ultrastructure studies indicated little change in granule morphology within mucus casts, whereas granules in laxative-treated mice appear to undergo limited dissolution. Protein extracts from CF intestine had increased levels of processed cryptdins compared with those from wild-type (WT) littermates. Nonetheless, colonization with aerobic bacteria species was not diminished in the CF intestine and oral challenge with a cryptdin-sensitive enteric pathogen, Salmonella typhimurium, resulted in greater colonization of CF compared with WT intestine. Modest downregulation of cryptdin and lysozyme mRNA in CF intestine was shown by microarray analysis, real-time quantitative PCR, and Northern blot analysis. Based on these findings, we conclude that antimicrobial peptide activity in CF mouse intestine is compromised by inadequate dissolution of Paneth cell granules within the crypt lumens. Total RNA was extracted from pooled small intestines of three WT and three CF mice using Tri-Reagent (Molecular Research Center, Cincinnati, OH), and poly(A) RNA was purified by using the MicroPoly(A) mRNA purification kit (Ambion, Austin, TX). The WT and CF poly(A) RNA samples were sent to IncyteGenomics (St. Louis, MO) where they were labeled with cyanine 3 (Cy3) and Cy5, respectively, and hybridized with the UniGEM1.31 array representing 9,570 known genes and expressed sequence tags.
Project description:DNA topoisomerase II (topo II) catalyzes a strand passage reaction in that one duplex is passed through a transient brake in another. Completion of late stages of neuronal development depends on the presence of active isoform (topo IIbeta). We identified topo IIbeta action sites on 7 selected genomic regions (about 79 Mb in total), each containing at least one gene that is controlled by topo IIbeta in neuronal differentiation. We used a novel method, etoposide-mediated topoisomerase immunoprecipitation (eTIP), followed by identification of precipitated DNA fragments on genomic tiling arrays. These DNA fragments were first fractionated by concentrated salt prior to the array analysis. The 0.5 M NaCl-released fraction was analyzed as P2 and the salt-resistant fraction wad analyzed as P1. The genomic DNA fractions from the immunoprecipitate (P1 or P2) were co-hybridized with a reference DNA isolated from the input of immunoprecipitation.
Project description:TuBo cell line (E) was compared to passage 1 (P1), 2 (P2) and 3 (P3) mammospheres to detect specific transcription isoforms associated to cancer stem cell. TuBo cell line (E) was compared to passage 1 (P1), 2 (P2) and 3 (P3) mammospheres. Exon-level transcription profiling was done using Affimetrix GeneChip Exon 1.0 ST. Exon-level analysis is more complex than gene-level analysis. The number of probesets to be investigated is at least 10 times larger in number than gene-level probesets. Thus results, upon statistical analysis, are massively contaminated by type I statistical errors, i.e. false positive [Della Beffa et al. 2008]. Furthermore, exon-level probesets are based only on four probes, which makes exon-level signal summarization more noisy than gene-level, where signal summarization is based on the overall probes encompassed by all exons of a gene. To moderate these issues we have expanded the number of experimental replications: six for TuBo and passage 1 mammosphere, four for passage 3 mammosphere and three for passage 2 mammosphere. Furthermore, after data summarization with RMA and normalization with sketch quantile method, alternative splicing detection between epithelial and mammospheres passages, was assessed using MiDAS, a two way anova developed by Affymetrix for the detection of alternative splicing events. We considered suitable for further investigations the splicing events in common between the sets of exons detected as spliced in each of the following comparisons: E vs P1, E vs P2 and E vs P3.
Project description:Despite correlations between histone methyltransferase (HMT) activity and gene regulation, direct evidence that HMT activity is responsible for gene activation is sparse. We address the role of the HMT activity for MLL1, a histone H3 lysine 4 (H3K4) methyltransferase critical for maintaining hematopoietic stem cells (HSCs). Here we show that the SET domain and thus HMT activity of MLL1 is dispensable for maintaining HSCs and for supporting leukemogenesis driven by the MLL-AF9 fusion oncoprotein. Upon Mll1 deletion, histone H4 lysine 16 (H4K16) acetylation was selectively depleted at MLL1 target genes in conjunction with reduced transcription. Surprisingly, inhibition of SIRT1 was sufficient to prevent the loss of H4K16 acetylation and the reduction in MLL1 target gene expression. Thus, recruited MOF activity, and not the intrinsic HMT activity of MLL1, is central for the maintenance of HSC target genes. In addition, this work reveals a role for SIRT1 in opposing MLL1 function. 11 Samples, 5 controls and 5 KOs with antibodies H3K4me1, H3K4me3, and H3K27Ac. One input Sample.
Project description:The efficacy of cancer treatments have improved constantly in the last decade. However, therapeutic resistance and the lack of curative treatments in metastatic disease, raises the question if conventional anticancer therapies target the right cells. Indeed, these treatments might miss cancer stem cells (CSCs), which might also represent a more chemoresistant and radioresistant subpopulation within cancer. In this view using vaccines in tertiary prevention of cancer, i.e. residual disease treatment, might be particularly effective if vaccine-elicited immune response is directed against CSC oncoantigens (OAs) M-bM-^@M-^T proteins required for the neoplastic process M-bM-^@M-^T the chance that the tumour will evade the vaccine should be reduced. An important task to devise effective CSC preventive vaccines is therefore the identification of CSC OAs. In this experiment we used a cell line (TuBo) derived by the mouse breast cancer model BALB-neuT and its CSC subpupolation, enriched by mean of mammosphere formation. Integrating data derived by gene and exon-level transcription profiling of the above experiments with public available normal and tumor datasets we identified two new breast cancer CSC OAs: TMPRSS4 and xCT. Both genes are linked to invasion, migration and metastasis. Furthermore, we observed that alternative splicing events discriminating TuBo cells, grown in adherent medium, with respect of TuBo mammospheres, produced growing in no-adherent medium, are very limited. We detect only one clear splcing event characterizing the beta-isoform of Rabgap1l gene. This SuperSeries is composed of the SubSeries listed below. The adherent TuBo epithelial cells were generated from a mammary carcinoma arising in a BALB/c mouse female transgenic for the activated rat ErbB2 oncogene (BALB-neuT) and were cultured in DMEM supplemented with 20% FCS. Single TuBo cells were plated in ultra low attachment flasks in serum-free DMEM-F12 medium supplemented with bFGF, EGF and insulin. Nonadherent spherical clusters of cells, named mammospheres, were collected by gentle centrifugation after 7 days and dissociated enzymatically and mechanically, using trypsin and pipetting, respectively.
Project description:The maize smut fungus, Sporisorium reilianum f. sp. zeae, which is an important biotrophic pathogen responsible for extensive crop losses, infects maize by invading the root during the early seedling stage. In order to investigate disease-resistance mechanisms at this early seedling stage, digital gene expression (DGE) analysis, which applies a dual-enzyme approach (DpnII and NlaIII), was used to identify the transcriptional changes in roots of Huangzao4 (susceptible) and Mo17 (resistant) after inoculation with teliospores of S. reilianum. Before and after inoculation, pathogenesis-related genes were differentially regulated and enzymes involved in controlling reactive oxygen species (ROS) levels showed different activity between Huangzao4 and Mo17, which can potentially lead to changes in the growth of S. reilianum and ROS production in maize. Moreover, lignin depositions of roots were also changed differentially during root colonization of hyphae between Huangzao4 and Mo17. These results suggest that the interplays between S. reilianum and maize during the early infection stage involve many interesting transcriptional and physiological changes, which offer several novel insights for understanding the mechanisms of resistance to the fungal infection. Examination of control stage (ck), post-inoculation stage1 (P1) and post-inoculation stage2 (P2) in Huangzao4 (susceptible) and Mo17 (resistant)