Transcription profiling of differential gene expression during Metacyclogenesis in 2 developmental stages in T.cruzei
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ABSTRACT: Evaluation of differential gene expression during the metacyclogenesis process in Trypanosoma cruzi, comparing three stages (epimastigotes, stressed epimastigotes and 24h adhered epimastigotes in differentiation) and using both total and polysomal mRNA.
Project description:To generate a high quality, annotated gene expression database of T. cruzi trypomastigotes(TRP), amastigotes (AMA), epimastigotes (EPI), and metacyclic trypomastigotes (MET). The global assessment of transcript abundances in each life-cycle stage of T. cruzi will identify stage-regulated genes and provide an essential element of an integrated database of T. cruzi genomic, proteomic, and transcriptomic data. RNAs from 3 biological replicates from a single time point in each stage will be subjected to DNA microarrays containing probes for the complete, annotated T. cruzi genome, as it is currently known. The arrays for this project will be provided by the Pathogen Functional Genomics Resource Center (PFGRC) at The Institute for Genomic Research (TIGR) sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), and will contain long oligonucleotides complementary to every annotated gene in the newly sequenced T. cruzi genome. The resulting data and analysis results will be deposited in TcruziDB (http://TcruziDB.org). Keywords: Gene expression comparisons between the four life-cycle stages of T. cruzi Six hybridizations were performed for each life-cycle stage. The hybridizations consisted of three dye-swap experiments from three independent samples (biological replicates). In each case, the experimental sample was from a single life-cycle stage and the control sample was an equal mixture of all four life-cycle stages. A total of 24 hybridizations were preformed.
Project description:PKR is an interferon induced serine/threonine protein kinase, that is activated by double stranded RNA. PKR plays an important role in the antiviral defense by interferon. In addition to its role in translation, PKR participates in several signaling pathways to transcription. The goal of this experiment is to study the role of PKR in regulating gene expression in our NIH 3T3 inducible cell line, which could overexpress PKR wt protein after the removal of tetracycline (Donze O, Dostie J, Sonenberg N. (1999) Virology 256: 322-9).
Project description:Small, non-coding RNAs control gene expression post-transcriptionally and play important roles in virus-host interactions. Within the liver, the microRNA (miRNA) miR-122 is essential for replication of hepatitis C virus (HCV), while repression of miR-148a by hepatitis B virus (HBV) may enhance tumorigenesis. Despite their importance to the outcome of these infections, few previous studies have described unbiased profiling of small RNAs in the liver during chronic viral hepatitis. Here, we sequenced small (14-40 nts) RNAs in liver from subjects with chronic hepatitis B and C. We found that small RNAs derived from tRNAs, specifically 5’ tRNA-halves (“5’ tRHs”, ~31-34 nts), are abundant in liver and significantly increased during chronic viral infection in humans and also chimpanzees. In most infected livers, 5’ tRH abundance exceeded that of miRNAs. In contrast, in hepatocellular carcinoma (HCC) tissue from these subjects, tRH abundance was reduced concomitant with decreased expression of the tRNA-cleaving ribonuclease, angiogenin. Although tRHs have been identified in mice, our results show they are abundantly expressed in human tissue, increased in chronic viral infection, and decreased in liver cancer. Our findings highlight the potential biological and clinical relevance of these small non-coding RNAs. Small RNA-seq of liver samples from control subjects (n=4), subjects with chronic hepatitis B (n=4) and hepatitis B associated hepatocellular carcinoma (n=4, 3 out of 4 matched with non-tumor tissue) and subjects with chronic hepatitis C (n=4) and tissue from hepatocellular carcinoma of the same patients. Also, small RNA-seq of AGO2 and IgG pulldown in FT3-7 cells. Sequenced AGO2 pulldown (n=3), IgG pulldown (n=2) and total small RNA from FT3-7 cells (n=3). This dataset is part of the TransQST collection.
Project description:CTCF binding polarity determines chromatin looping CTCF ChIPseq was performed in E14 embryonic stem cells and neural precursor cells
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is mostly characterized by specific chromosomal abnormalities, some occurring in a mutually exclusive manner possibly delineating specific T-ALL subgroups. One subgroup, including MLL-rearranged, CALM-AF10 or inv(7)(p15q34) cases, is characterized by elevated expression of HOXA genes. Using a gene expression based clustering analysis of 67 T-ALL cases with recurrent molecular genetic abnormalities and 25 samples lacking apparent aberrations, we identified 5 new cases with elevated HOXA levels. Using array-CGH, a cryptic and recurrent deletion, del(9)(q34.11q34.13), was exclusively identified in 3 of these 5 cases. This deletion results in a conserved SET-NUP214 fusion product, that was also identified in the T-ALL cell line LOUCY. SET-NUP214 binds in the promoter regions of specific HOXA genes, where it may interact with CRM1 and DOT1L leading to the transcriptional activation of HOXA genes. Targeted inhibition of SET-NUP214 by siRNA abolished expression of HOXA genes, inhibited proliferation and induced differentiation in LOUCY but not in other T-ALL lines. We conclude that SET-NUP214 may contribute to the pathogenesis of T-ALL by enforcing T-cell differentiation arrest. We combined gene expression profiling and array-CGH analysis to detect a new and recurrent molecular cytogenetic abnormality in T-ALL patients that co-clustered with 5 well-defined HOXA-activated T-ALL samples. We describe the cloning of a recurrent SET-NUP214 fusion product in these samples, and identified a potential mechanism by which SET-NUP214 may activate the HOXA gene cluster as potential leukemogenic event in T-ALL. Experiment Overall Design: For 67 T-ALL patients having one of the major molecular cytogenetic abnormalities (i.e. TAL1 (n=24), LMO2 (n=9), HOXA (n=5), HOX11/TLX1 (n=7), and HOX11L2/TLX3 (n=22)), differentially expressed probesets were calculated from Affymetrix U133plus2.0 data based upon a Wilcoxon analysis and corrected for multiple testing for each probeset. Significant and differentially expressed probesets were obtained for the TAL1, HOX11 and HOX11L2 subgroups. No significant probesets were obtained for the HOXA subgroup or the LMO2 subgroup . As TAL1 and LMO2 both participate in the same transcriptional complex, activation of these genes may both lead to a highly similar expression profile. Combined analysis of TAL1 and LMO2 rearranged cases revealed significant and differentially expressed probesets that, as expected, almost entirely overlapped with the gene signature obtained for the TAL1-subgroup only. Next, we clustered 92 T-ALL cases, that besides the 67 cases as described above further included 25 T-ALL that lacked any of these recurrent abnormalities. Cluster analysis was performed based upon the top 25, 50 or 100 most significant probesets for the TAL1, TAL1/LMO2, HOX11 and HOX11L2 subgroups combined with 15 HOXA probesets identified by Soulier et al (2005)
Project description:To identify novel oncogenic pathways in T-cell acute lymphoblastic leukemia (T-ALL), we combined expression profiling of 117 pediatric patient samples and detailed molecular cytogenetic analyses including the Chromosome Conformation Capture on Chip (4C) method. Two T-ALL subtypes were identified that lacked rearrangements of known oncogenes. One subtype associated with cortical arrest, expression of cell cycle genes and ectopic NKX2-1 or NKX2-2 expression for which rearrangements were identified. The second subtype associated with immature T-cell development and high expression of the MEF2C transcription factor as consequence of rearrangements of MEF2C, transcription factors that target MEF2C or MEF2C-associated cofactors. We propose NKX2-1, NKX2-2 and MEF2C as T-ALL oncogenes that are activated by various rearrangements. This study includes 117 pediatric T-ALL samples of which 92 samples are available at GSE10609. In addition, this study includes 7 normal bone marrow control samples
Project description:The orphan nuclear receptor Nurr1 has been shown to be critical for the development of ventral midbrain dopaminergic neurons. Consequently, the development of ES cells overexpressing Nurr1 has raised hope for the development of cell replacement therapies for Parkinson's Disease to replace degenerated dopaminergic neurons. However, the molecular consequences of Nurr1 on gene expression in these cells remain unknown. To address this, stable, clonal, c17.2 neural stem cell lines were established that overexpressed the orphan nuclear receptor Nurr1 (clone 42 & clone 48) or parental control cell line (puroB & puroD, respectively). Experiment Overall Design: Stable neural stem cell lines were grown in proliferating conditions and matched for further microarray analysis based on their similar proliferation rates: Experiment Overall Design: clone 42(c42) vs. puroB(pB) Experiment Overall Design: clone 42(c48) vs. puroD(pD)
Project description:Glucocorticoid resistance is a major driver of therapeutic failure in T-cell acute lymphoblastic leukemia (T-ALL). Here we used a systems biology approach, based on the reverse engineering of signaling regulatory networks, which identified the AKT1 kinase as a signaling factor driving glucocorticoid resistance in T-ALL. Indeed, activation of AKT1 in T-ALL lymphoblasts impairs glucocorticoid-induced apoptosis. Mechanistically, AKT1 directly phosphorylates the glucocorticoid receptor NR3C1 protein at position S134 and blocks glucocorticoid-induced NR3C1 translocation to the nucleus. Consistently, inhibition of AKT1 with MK-2206 increases the response of T-ALL cells to glucocorticoid therapy both in T-ALL cell lines and in primary patient samples thus effectively reversing glucocorticoid resistance in vitro and in vivo. These results warrant the clinical testing of ATK1 inhibitors and glucocorticoids, in combination, for the treatment of T-ALL. This study includes 228 T-ALL samples of which 117 samples are re-analysis of GSE26713.