In Drosophila, PIWI proteins and bound PIWI interacting RNAs (piRNAs) form the core of a small RNA mediated defense system against selfish genetic elements. Within germline cells piRNAs are processed from piRNA clusters and transposons to be loaded into Piwi/Aubergine/AGO3 and a subset of piRNAs undergoes target dependent amplification. In contrast, gonadal somatic support cells express only Piwi, lack signs of piRNA amplification and exhibit primary piRNA biogenesis from piRNA clusters. Neither piRNA processing/loading nor Piwi mediated target silencing is understood at the genetic, cellular or molecular level. We developed an in vivo RNAi assay for the somatic piRNA pathway and identified the RNA helicase Armitage, the Tudor domain containing RNA helicase Yb and the putative nuclease Zucchini as essential factors for primary piRNA biogenesis. Lack of any of these proteins leads to transposon de-silencing, to a collapse in piRNA levels and to a failure in Piwi nuclear accumulation. We show that Armitage and Yb interact physically and co-localize in cytoplasmic Yb-bodies, which flank P-bodies. Loss of Zucchini leads to an accumulation of Piwi and Armitage in Yb-bodies indicating that Yb-bodies are sites of primary piRNA biogenesis. Overall design: small RNA libraries were prepared from Piwi immuno-precipitates of five different genotypes
An in vivo RNAi assay identifies major genetic and cellular requirements for primary piRNA biogenesis in Drosophila.
Subject
View SamplesThe below table includes a smaller list of data that was analyzed by dChip and filtered by pvalue such that a file with about 4600 genes was obtained, which allowed for ease of use from 40,000 genes.
Identification of mechanosensitive genes in osteoblasts by comparative microarray studies using the rotating wall vessel and the random positioning machine.
Specimen part
View SamplesDespite the importance of inter-cellular communication networks in regulating stem cell fate decisions, very little is known about the topology, dynamics, or functional significance. Using human blood stem cell cultures as an experimental paradigm, we present a novel bioinformatic approach to integrate genome-scale molecular profiles (transcriptome and secretome) and publicly available databases to reconstruct soluble factor-mediated inter-cellular signalling networks regulating blood stem cell fate decisions.
Dynamic interaction networks in a hierarchically organized tissue.
Specimen part
View SamplesBackground: Patients with early stage non-small cell lung carcinoma (NSCLC) may benefit from treatments based on more accurate prognosis. A 15-gene prognostic classifier for NSCLC was identified from mRNA expression profiling of tumor samples from the NCIC CTG JBR.10 trial. Here, we assessed its value in an independent set of cases.
Validation of a histology-independent prognostic gene signature for early-stage, non-small-cell lung cancer including stage IA patients.
Sex, Age
View SamplesMonocytes are derived from hematopoietic stem cells through a series of intermediate progenitor stages, but the factors that regulate this process are incompletely defined. Using a Ccr2/Cx3cr1 dual-reporter system to model murine monocyte ontogeny, we conducted a small molecule screen that identified an essential role of mechanistic target of rapamycin complex 1 (mTORC1) in the development of monocytes and other myeloid cells. Overall design: Examination of gene expression in 1) Granulocyte-Monocyte Progenitors from Raptor KO mice, Tsc2 KO mice and controls; and 2) DR-ER-Hoxb8 cells differentiated in the presence of DMSO, rapamycin or SL0101-01
The metabolic regulator mTORC1 controls terminal myeloid differentiation.
Specimen part, Cell line, Subject
View SamplesCerebral organoids – three-dimensional cultures of human cerebral tissue derived from pluripotent stem cells – have emerged as models of human cortical development. However, the extent to which in vitro organoid systems recapitulate neural progenitor cell proliferation and neuronal differentiation programs observed in vivo remains unclear. Here we use single-cell RNA sequencing (scRNA-seq) to dissect and compare cell composition and progenitor-to-neuron lineage relationships in human cerebral organoids and fetal neocortex. Covariation network analysis using the fetal neocortex data reveals known and novel interactions among genes central to neural progenitor proliferation and neuronal differentiation. In the organoid, we detect diverse progenitors and differentiated cell types of neuronal and mesenchymal lineages, and identify cells that derived from regions resembling the fetal neocortex. We find that these organoid cortical cells use gene expression programs remarkably similar to those of the fetal tissue in order to organize into cerebral cortex-like regions. Our comparison of in vivo and in vitro cortical single cell transcriptomes illuminates the genetic features underlying human cortical development that can be studied in organoid cultures. Overall design: 734 single-cell transcriptomes from human fetal neocortex or human cerebral organoids from multiple time points were analyzed in this study. All single cell samples were processed on the microfluidic Fluidigm C1 platform and contain 92 external RNA spike-ins. Fetal neocortex data were generated at 12 weeks post conception (chip 1: 81 cells; chip 2: 83 cells) and 13 weeks post conception (62 cells). Cerebral organoid data were generated from dissociated whole organoids derived from induced pluripotent stem cell line 409B2 (iPSC 409B2) at 33 days (40 cells), 35 days (68 cells), 37 days (71 cells), 41 days (74 cells), and 65 days (80 cells) after the start of embryoid body culture. Cerebral organoid data were also generated from microdissected cortical-like regions from H9 embryonic stem cell derived organoids at 53 days (region 1, 48 cells; region 2, 48 cells) or from iPSC 409B2 organoids at 58 days (region 3, 43 cells; region 4, 36 cells).
Human cerebral organoids recapitulate gene expression programs of fetal neocortex development.
No sample metadata fields
View SamplesWe investigated the role of mTORC1 in murine hematopoiesis by conditionally deleting the Raptor gene in murine hematopoietic stem cells. We observed mutliple alterations evoked by Raptor loss in hematopoiesis and profiled gene-expression alterations induced by raptor loss in Flt3-Lin-Sca1+cKit+ hematopoietic stem and progenitor enriched cell populations, 5 weeks post Raptor deletion.
mTOR complex 1 plays critical roles in hematopoiesis and Pten-loss-evoked leukemogenesis.
Specimen part
View SamplesAberrant expression of the homeodomain transcription factor CDX2 occurs in most cases of acute myeloid leukemia (AML) and promotes leukemogenesis, making CDX2, in principle, an attractive therapeutic target. Conversely, CDX2 acts as a tumor suppressor in colonic epithelium. The effectors mediating the leukemogenic activity of CDX2 and the mechanism underlying its context-dependent properties are poorly characterized, and strategies for interfering with CDX2 function in AML remain elusive. We report data implicating repression of the transcription factor KLF4 as important for the oncogenic activity of CDX2, and demonstrate that CDX2 differentially regulates KLF4 in AML versus colon cancer cells through a mechanism that involves tissue-specific patterns of promoter binding and epigenetic modifications. Furthermore, we identified deregulation of the PPAR signaling pathway as a feature of AML expressing CDX2, and observed that PPAR agonists derepress KLF4 and are preferentially toxic to CDX2-positive leukemic cells. These data delineate transcriptional programs associated with CDX2 expression in hematopoietic cells; provide insight into the antagonistic duality of CDX2 function in AML versus colon cancer; and suggest reactivation of KLF4 expression, through modulation of PPAR signaling, as a new therapeutic modality in a large proportion of AML patients.
CDX2-driven leukemogenesis involves KLF4 repression and deregulated PPARγ signaling.
No sample metadata fields
View SamplesMany cases of acute myeloid leukemia (AML) are associated with mutational activation of RTKs such as FLT3. However, RTK inhibitors have limited clinical efficacy as single agents, indicating that AML is driven by concomitant activation of different signaling molecules. We used a functional genomic approach to identify RET, encoding an RTK not previously implicated in AML, as essential gene in different AML subtypes, and observed that RET-dependent AML cells show activation of RET signaling via ARTN/GFRA3 and NRTN/GFRA2 ligand/co-receptor complexes.
RET-mediated autophagy suppression as targetable co-dependence in acute myeloid leukemia.
Specimen part, Disease
View SamplesPrimary pneumocytes from KRas;Atg5fl/+ and KRas;Atg5fl/fl littermates were cultured for 48 hours and infected with AdCre-GFP to induce expression of the KrasG12D oncogene and concomitant Atg5 deletion. The transcriptional profile of those cells was determined by mRNA sequencing and uncovered differential expression in cellular movement, inflammatory response and oxidative stress response. Overall design: Comparison of transcriptomes from KRas;Atg5fl/+ and KRas;Atg5fl/fl pneumocytes
A dual role for autophagy in a murine model of lung cancer.
Specimen part, Subject
View Samples