In the past few years, mammary cancer initiating cells (CICs) have been identified in mouse and human as a subpopulation of tumor cells that selectively posses tumor initiation and self-renewal capacity and the ability to give rise to bulk populations of non-tumorigenic cancer cells progeny through differentiation. They could also be responsible for tumor progression, metastasis, resistance to therapy and recurrence. Thus, the understanding of the pathways regulating CIC self-renewal, differentiation and tumorigenicity represents an important task in the development of effective anticancer therapies.
The noninflammatory role of high mobility group box 1/Toll-like receptor 2 axis in the self-renewal of mammary cancer stem cells.
Specimen part, Cell line
View SamplesIn order to assess the physiological role of Cop1 in vivo we generated mice that do no longer express the protein. Cop1KO mice die at around E10.5 of embryonic development. In order to gain insights into the molecular mechanisms that cause the embryonic death we compared the genome-wide gene expression profile of E9.5 wild-tytpe and Cop1-null embryos. The data do not support a role for Cop1 in the regulation of the p53 pathway in vivo and highlight a role for Cop1 in cardiovascular development and/or angiogenesis. The abstract of the associated publication is as follows:Biochemical data have suggested conflicting roles for the E3 ubiquitin ligase Cop1 in tumourigenesis. Here we present the first in vivo investigation of the role of Cop1 in cancer aetiology. We used an innovative genetic approach to generate an allelic series of Cop1 and show that Cop1 hypomorphic mice spontaneously develop malignancy at a high frequency in their first year of life and are highly susceptible to radiation-induced lymphomagenesis. Biochemically, we show that Cop1 regulates c-Jun oncoprotein stability and modulates c-Jun/AP1 transcriptional activity in vivo. Cop1-deficiency stimulates cell proliferation in a c-Jun-dependent manner. We conclude that Cop1 is a tumour suppressor that antagonizes c-Jun oncogenic activity in vivo.
Cop1 constitutively regulates c-Jun protein stability and functions as a tumor suppressor in mice.
Specimen part
View SamplesTumors driven by activation of the transcription factor Myc generally show oncogene addiction. However, the gene-expression programs that depend upon sustained Myc activity in those tumors remain unknown. We have addressed this issue in a model of liver carcinoma driven by a reversible tet-Myc transgene, combining gene expression profiling with the mapping of Myc and RNA Polymerase II on chromatin. Switching off the oncogene in advanced carcinomas revealed that Myc is required for the continuous activation and repression of distinct sets of genes, constituting no more than half of those deregulated during tumor progression, and an even smaller subset of all Myc-bound genes. We further showed that a Myc mutant unable to associate with the co-repressor protein Miz1 is defective in the initiation of liver tumorigenesis. Altogether, our data provide the first detailed analysis of a Myc-dependent transcriptional program in a fully developed carcinoma, revealing that the critical effectors of Myc in tumor maintenance must be included within defined subsets (ca. 1,300 each) of activated and repressed genes. Overall design: RNAseq samples of control liver (n=11), tet-Myc tumors (n=16), tet-Myc tumors with short-term Myc inactivation (n=8), tet-MycVD tumors (n=11)
Identification of MYC-Dependent Transcriptional Programs in Oncogene-Addicted Liver Tumors.
Specimen part, Cell line, Subject
View SamplesTo investigate the specific gene expression program by which mutant-p53 and Pin1 control invasion and metastasis in breast cancer cells, we compared the transcriptomic profile of control, mutant-p53 depleted or Pin1 depleted MDA-MB-231 cells.
A Pin1/mutant p53 axis promotes aggressiveness in breast cancer.
Cell line
View SamplesCombining an in vitro hNCC differentiation protocol with epigenomic profiling, we provide the first whole-genome characterization of cis-regulatory elements in this highly relevant cell type. With this data at hand, we have characterized the chromatin state and dynamics of all human gene promoters during the course of NCC in vitro differentiation. Most importantly, we have identified a large cohort of active and NCC-specific enhancers, which we showed to be functionally relevant in vivo, in the context of embryonic development. Finally, through sequence analysis of the identified NCC enhancers, we uncovered the orphan nuclear receptors NR2F1 and NR2F2 as novel hNCC transcriptional regulators both in vitro and in vivo. Overall design: RNA-seq experiments in human neural crest cells (hNCC)
Epigenomic annotation of enhancers predicts transcriptional regulators of human neural crest.
No sample metadata fields
View SamplesFollowing implantation, mouse epiblast cells transit from a naïve to a primed state in which they are competent for both somatic and primordial germ cell (PGC) specification. Using mouse embryonic stem cells (mESC) as an in vitro model to study the transcriptional regulatory principles orchestrating peri-implantation development, here we show that the transcription factor Foxd3 is necessary for the exit from naïve pluripotency and the progression to a primed pluripotent state. During this transition, Foxd3 acts as a repressor that dismantles a significant fraction of the naïve pluripotency expression program through the decommissioning of active enhancers associated with key naïve pluripotency and early germline genes. Subsequently, Foxd3 needs to be silenced in primed pluripotent cells to allow the reactivation of relevant genes required for proper PGC specification. Our findings uncover a wave of activation-deactivation of Foxd3 as a crucial step for the exit from naïve pluripotency and subsequent PGC specification. Overall design: mRNA profiles were generated by RNA-seq in duplicates for each of the following mESC lines: Foxd3fl/fl;Cre-ER mESC maintained in "Serum+LIF" (SL) treated with TM for three days (SL Foxd3-/-); untreated Foxd3fl/fl;Cre-ER SL mESC (SL Foxd3fl/fl); tetON Foxd3 SL mESC treated with Dox for three days; WT SL mESC treated with Dox for three days; Foxd3fl/fl;Cre-ER mESC maintained in "2i+LIF" (2i) treated with TM for three days (2i Foxd3-/-); untreated Foxd3fl/fl;Cre-ER 2i mESC (2i Foxd3fl/fl).
Foxd3 Promotes Exit from Naive Pluripotency through Enhancer Decommissioning and Inhibits Germline Specification.
No sample metadata fields
View SamplesBALB/c mice are susceptible to proteoglycan (PG) aggrecan-induced arthritis (PGIA), and the absence of TSG-6 further increases susceptibility and local inflammatory reactions, including neutrophil invasion into the joints. To gain insight into the mechanisms of TSG-6 action, synovial fibroblasts were isolated from wild-type and TSG-6-KO mice, cultured and exposed to various agents affecting either the TSG-6 expression and/or modify the intracellular function of TSG-6.
TSG-6 protein, a negative regulator of inflammatory arthritis, forms a ternary complex with murine mast cell tryptases and heparin.
Sex, Treatment
View SamplesThis experiment analyzes the changes in expression of twelve days old Arabidopsis roots at ten hours post inoculation upon cyst nematode H. schachtii infection.
Arabidopsis leucine-rich repeat receptor-like kinase NILR1 is required for induction of innate immunity to parasitic nematodes.
Age, Specimen part
View SamplesThis experiment analyzes the changes in expression of ten days old Arabidopsis roots upon NemaWater treatment.
Arabidopsis leucine-rich repeat receptor-like kinase NILR1 is required for induction of innate immunity to parasitic nematodes.
Age, Specimen part
View SamplesPoised enhancers marked by H3K27me3 in pluripotent cells were previously proposed to facilitate the establishment of somatic expression programs upon embryonic stem cell (ESC) differentiation. However, the functional relevance and mechanism of action of poised enhancers remain unknown. Here, we use genetic deletions to demonstrate that poised enhancers are necessary for the induction of major anterior neural regulators. Mechanistically, poised enhancers enable RNA Polymerase II recruitment to their cognate promoters upon differentiation. Interestingly, poised enhancers already establish physical interactions with their target genes in ESC in a Polycomb repressive complex 2 (PRC2) dependent manner. Loss of PRC2 led to neither the activation of poised enhancers nor the induction of their putative target genes in undifferentiated ESC. In contrast, loss of PRC2 severely and specifically compromised the induction of major anterior neural genes representing poised enhancer targets. Overall, our work illuminates a novel function for polycomb proteins, which we propose facilitate neural induction by providing major anterior neural loci with a permissive regulatory topology. Overall design: mRNA profiles were generated by RNA-seq from mESC and AntNPC for the following lines: WT mESC, WT AntNPC, EED-/- mESC and EED-/- AntNPC
PRC2 Facilitates the Regulatory Topology Required for Poised Enhancer Function during Pluripotent Stem Cell Differentiation.
Specimen part, Treatment, Subject
View Samples