We used next generation sequencing to analyze the gene expression changes in U2OS osteosarcoma cells expressing shRNA targeting the promyelocytic leukemia (PML) gene transcripts Overall design: cDNA libraries of U2OS cells expressing control shRNA or shRNA targeting PML were generated from one biological replicate
PML nuclear bodies contribute to the basal expression of the mTOR inhibitor DDIT4.
No sample metadata fields
View SamplesThe objective of this study was to decipher the molecular basis of feed efficiency in meat-type chicken using duodenum tissues from a chicken population divergently selected for residual feed intake (RFI). Residual feed intake is the deviation of expected feed intake from actual feed intake. Chickens that consume less feed than expected are efficient (LRFI) and chickens that consume more feed than expected are inefficient (HRFI). A divergent selection for RFI was undertaken using an unselected random bred chicken population. RFI at day 35-42 was used as a criterion for selecting low (LRFI) and high (HRFI) RFI. Duodenum tissues were collected from 16 male chickens under sterile conditions experimentation. Tissues were collected from 4 males at days 35 and 42 in each line.
Transcriptomic analysis to elucidate the molecular mechanisms that underlie feed efficiency in meat-type chickens.
Specimen part
View SamplesDisruptions of the endoplasmic reticulum (ER) that perturb protein folding cause ER stress and elicit an unfolded protein response (UPR) that involves translational and transcriptional changes in gene expression aimed at expanding the ER processing capacity and alleviating cellular injury. Three ER stress sensors PERK, ATF6, and IRE1 implement the UPR. PERK phosphorylation of eIF2 during ER stress represses protein synthesis, which prevents further influx of ER client proteins, along with preferential translation of ATF4, a transcription activator of the integrated stress response. In this study we show that the PERK/eIF2~P/ATF4 pathway is required not only for translational control, but also activation of ATF6 and its target genes. The PERK pathway facilitates both the synthesis of ATF6 and trafficking of ATF6 from the ER to the Golgi for intramembrane proteolysis and activation of ATF6. As a consequence, liver-specific depletion of PERK significantly reduces both the translational and transcriptional phases of the UPR, leading to reduced protein chaperone expression, disruptions of lipid metabolism, and enhanced apoptosis. These findings show that the regulatory networks of the UPR are fully integrated, and helps explain the diverse pathologies associated with loss of PERK.
The eIF2 kinase PERK and the integrated stress response facilitate activation of ATF6 during endoplasmic reticulum stress.
Specimen part, Treatment
View SamplesDisruption of protein folding in the endoplasmic reticulum triggers the Unfolded Protein Response (UPR), a transcriptional and translational control network designed to restore protein homeostasis. Central to the UPR is PERK phosphorylation of the alpha subunit of eIF2 (eIF2~P), which represses global translation coincident with preferential translation of mRNAs, such as ATF4 and CHOP, that serve to implement the UPR transcriptional regulation. In this study, we used sucrose gradient ultracentrifugation and a genome-wide microarray approach to measure changes in mRNA translation during ER stress. Our analysis suggests that translational efficiencies vary across a broad range during ER stress, with the majority of transcripts being either repressed or resistant to eIF2~P, while a notable cohort of key regulators are subject to preferential translation. From this latter group, we identify IBTKa as being subject to both translation and transcriptional induction during eIF2~P in both cell lines and a mouse model of ER stress. Translational regulation of IBTKalpha mRNA involves the stress-induced relief of two inhibitory uORFs in the 5'-leader of the transcript. Depletion of IBTKalpha by shRNA reduced viability of cultured cells coincident with increased caspase 3/7 cleavage, suggesting that IBTKalpha is a key regulator in determining cell fate during the UPR.
Selective mRNA translation during eIF2 phosphorylation induces expression of IBTKα.
Specimen part
View SamplesWe report the physiological role of ATF4 within mouse liver, under basal and ER stress conditions. With three mice per group, and approximately 30 million reads per sample, we obtained genome-wide role of ATF4 within the liver. We find ATF4 is responsible for a small subset of ER stress genes, and larger than previously thought basal subset. Overall design: Examination of the loss of ATF4 basally and during 6 hour Tunicamycin induced ER stress
Transcription factor ATF4 directs basal and stress-induced gene expression in the unfolded protein response and cholesterol metabolism in the liver.
Specimen part, Cell line, Treatment, Subject
View SamplesHuntington neurodegenerative disease (HD) is associated with extensive down-regulation of neuronal genes. We show preferential down-regulation of super-enhancer-regulated neuronal function genes in the striatum of HD mice. Striatal super-enhancers display extensive H3K27 acetylation within gene bodies and drive transcription characterized by low levels of paused RNAPII. Down-regulation of gene expression is associated with diminished H3K27 acetylation and RNAPII recruitment. Striatal super-enhancers are enriched in binding motifs for Gata transcription factors, such as Gata2 regulating striatal identity genes. Thus, enhancer topography and transcription dynamics are major parameters determining the propensity of a gene to be deregulated in a neurodegenerative disease. Overall design: RNA profiles in Striatum of WT and R6/1 mice by deep sequencing using Illumina HiSeq 2000.
Altered enhancer transcription underlies Huntington's disease striatal transcriptional signature.
No sample metadata fields
View SamplesInhibition of mTOR signaling using the rapalog everolimus is an FDA-approved targeted therapy for patients with lung and gastroenteropancreatic neuroendocrine tumors (NET). However, patients eventually progress on treatment, highlighting the need for additional therapies. We focused on pancreatic NETs (pNETs) and reasoned that treatment of these tumors upon progression on rapalog therapy, with an mTOR kinase inhibitor (mTORKi) such as CC-223 could overcome a number of resistance mechanisms in tumors and delay cardiac carcinoid disease. We performed preclinical studies using human pNET cells in vitro and injected them subcutaneously or orthotopically to determine tumor progression and cardiac function in mice treated with either rapamycin alone or switched to CC-223 upon progression. Detailed signaling and RNA sequencing analyses were performed on tumors that were sensitive or progressed on mTOR treatment. Approximately 57% of mice bearing pNET tumors which progressed on rapalog therapy showed a significant decrease in tumor volume upon a switch to CC-223. Moreover, mice treated with an mTORKi exhibited decreased cardiac dilation and thickening of heart valves than those treated with placebo or rapamycin alone. In conclusion, in the majority of pNETs that progress on rapalogs, it is possible to reduce disease progression using an mTORKi, such as CC-223. Moreover, CC-223 had an additional transient cardiac benefit on valvular fibrosis compared to placebo- or rapalog-treated mice. These results provide the preclinical rationale to further develop mTORKi clinically upon progression on rapalog therapy and to further test their long term cardioprotective benefit in those NET patients prone to carcinoid syndrome. Overall design: We performed RNA sequencing analyses as an unbiased means to assess changes in gene expression. Our major goal was to identify the differences in tumor mRNAs between the CC-223- and non-CC-223 responders compared to the rapamycin alone treatment arm (Fig 5A in Orr-Asman et al manuscript). The analysis was conducted using 1 tumor each from 13 and 14 mice treated with rapamycin or switched to CC-223 respectively.
mTOR Kinase Inhibition Effectively Decreases Progression of a Subset of Neuroendocrine Tumors that Progress on Rapalog Therapy and Delays Cardiac Impairment.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Loss of PRDM11 promotes MYC-driven lymphomagenesis.
Specimen part, Cell line
View SamplesThe PR-domain family (PRDMs) encodes transcriptional regulators, several of which are deregulated in cancer. We found that loss of Prdm11 accelerates MYC-driven lymphomagenesis in the E-Myc mouse model.
Loss of PRDM11 promotes MYC-driven lymphomagenesis.
Specimen part
View SamplesThe PR-domain family e(PRDMs) encodes transcriptional regulators, several of which are deregulated in cancer. We found that loss of Prdm11 accelerates MYC-driven lymphomagenesis in the Eµ-Myc mouse model. Moreover, we show that patients with PRDM11-deficient diffuse large B cell lymphomas (DLBCLs) have poorer overall survival and belong to the non-Germinal Center B cell (GCB)-like subtype. Mechanistically, genome-wide mapping of PRDM11 binding sites coupled with transcriptome sequencing in human DLBCL cells evidenced that PRDM11 associates with transcriptional start sites of target genes and regulates important oncogenes such as FOS and JUN. Hence, we characterize PRDM11 as a novel tumor suppressor controlling the expression of key oncogenes and add new mechanistic insight into B-cell lymphomagenesis. Overall design: RNA-seq performed after knockdown of Prdm11
Loss of PRDM11 promotes MYC-driven lymphomagenesis.
No sample metadata fields
View Samples