Cancer cells have abnormal gene expression profiles, however, the transcription factors and the architecture of the regulatory network that drive cancer specific gene expression is often not known. Here we studied a model of Ras-driven invasive tumorigenesis in Drosophila epithelial tissues and combined in vivo genetics with high-throughput sequencing and computational modeling to decipher the regulatory logic of tumor cells. Surprisingly, we discovered that the bulk of the tumor specific gene expression is driven by an ectopic network of a few transcription factors that are overexpressed and/or hyperactivated in tumor cells. These factors are Stat, AP-1, the bHLH proteins Myc and AP-4, the nuclear hormone receptor Ftz-f1, the nuclear receptor coactivator Taiman/AIB1, and Mef2. Notably, many of these transcription factors are also hyperactivated in human tumors. Bioinformatics analysis predicted that these factors directly regulate the majority of the tumor specific gene expression, that they are interconnected by extensive cross-regulation, and that they show a high degree of co-regulation of target genes. Indeed, the factors of this network were required in multiple epithelia for tumor growth and invasiveness and knock-down of individual factors caused a reversion of the tumor specific expression profile, but had no observable effect on normal tissues. We further found that the Hippo pathway effector Yki/Sd was strongly activated in tumor cells and initiated cellular reprogramming by activating several transcription factors of this network. Thus, modeling regulatory networks identified an ectopic yet highly ordered network of master regulators that control tumor cell specific gene expression. Overall design: RNA-seq gene expression profiling across Drosophila 3rd instar larval wild type wing discs and genetic perturbations of wts.
An Ectopic Network of Transcription Factors Regulated by Hippo Signaling Drives Growth and Invasion of a Malignant Tumor Model.
Subject, Time
View SamplesUnder stress conditions mammalian cells activate compensatory mechanisms to survive and maintain cellular function. During catabolic conditions, such as low nutrients, systemic inflammation, cancer or infections, protein breakdown is enhanced and aminoacids are released from muscles to sustain liver gluconeogenesis and tissues protein synthesis. Proteolysis in muscle is orchestrated by a set of genes named atrophy-related genes. A system that is activated both in short and prolonged stress conditions is the family of Forkhead Box (Fox) O transcription factors. Here, we report that muscle-specific deletion of FoxO members resulted in protection from muscle loss because FoxO family is required for induction of autophagy-lysosome and ubiquitin-proteasome systems. Importantly, FoxOs are required for Akt activity but not for mTOR signalling underlining the concept that FoxOs are upstream mTOR for the control of protein breakdown when nutrients are lacking. Moreover, FoxO family controls the induction of critical genes belonging to several fundamental stress response pathways such as unfolded protein response, ROS detoxification and translational regulation. Finally, we identify a set of novel FoxO-dependent ubiquitin ligases including the recent discovered MUSA11 and a new one, which we named Specific of Muscle Atrophy and Regulated by Transcription (SMART). Our findings identify the critical role of FoxO in regulating a variety of genes belonging to pathways important for stress-response under catabolic conditions.
Regulation of autophagy and the ubiquitin-proteasome system by the FoxO transcriptional network during muscle atrophy.
Sex
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcription Factor EB Controls Metabolic Flexibility during Exercise.
Age, Specimen part
View SamplesIn order to identify the effects of the absence of Tcfeb on the muscle transcriptome, we performed Affymetrix Gene-Chip hybridization experiments for the KO mice as compared with wt mice
Transcription Factor EB Controls Metabolic Flexibility during Exercise.
Age, Specimen part
View SamplesAnalysis of gene-probe expression data (FPKM) for mouse skin using single-end read RNA-seq Overall design: RNA was collected and analyzed for 2 biological replicates each from 3 developmental stages (E18.5, P3, 10 weeks)
RNA-seq studies reveal new insights into p63 and the transcriptomic landscape of the mouse skin.
No sample metadata fields
View SamplesWe developed a Tet-inducible system to express deltaNp63alpha isoform under the control of keratin 5 promoter. Transgenic mice, which were Bigenic (BG) developed a severe skin phenotype with abnormal keratinocyte differentiation and defects in hair follicle development and cycling. Skin samples from transgenic animals and wild type animals were analyzed for global transcriptome changes.
Abnormal hair follicle development and altered cell fate of follicular keratinocytes in transgenic mice expressing DeltaNp63alpha.
Specimen part
View SamplesTo define target genes of the intestine-restricted transcription factor (TF) CDX2 in intestinal stem cells, we performed chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-Seq). We used RNA-sequencing to profile gene expression changes during cell differentiation from mouse intestinal stem cells to mature villus cells, as well as genes perturbed in intestinal stem cells upon loss of Cdx2. We find thousands of genes that change in expression during cell differentiation, including known stem cell and mature markers. Upon loss of Cdx2, hundreds of genes are up and down-regulated in intestinal stem cells, some of which are also bound by CDX2 nearby and constitute candidate direct target genes. Overall design: CDX2 ChIP-Seq analysis of isolated mouse intestinal stem cells. RNA seq analysis of control mouse villus cells, control intestinal stem cells and Cdx2-deleted intestinal stem cells.
Distinct Processes and Transcriptional Targets Underlie CDX2 Requirements in Intestinal Stem Cells and Differentiated Villus Cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Intestinal master transcription factor CDX2 controls chromatin access for partner transcription factor binding.
Specimen part
View SamplesAnalysis of gene expression changes during mouse salivary gland development using RNA-Seq Overall design: RNA was collected and analyzed for at least two biological replicates each from six developmental timepoints (E14.5, E16.5, E18.5, P5, 4 weeks, 12 weeks)
RNA-seq based transcriptomic map reveals new insights into mouse salivary gland development and maturation.
Age, Specimen part, Cell line, Subject
View SamplesWe established whether partner transcription factor binding, chromatin structure, or gene expression is compromised upon loss of partner factors cdx2 or hnf4a in mouse intestinal villi
Intestinal master transcription factor CDX2 controls chromatin access for partner transcription factor binding.
Specimen part
View Samples