X-chromosome aneuploidies have long been associated with human cancers, but causality has not been established. In mammals, X-chromosome inactivation (XCI) is triggered by Xist RNA to equalize gene expression between the sexes. Here we delete Xist in the blood compartment of mice and demonstrate that mutant females develop a highly aggressive myeloproliferative neoplasm and myelodysplastic syndrome (mixed MPN/MDS) with 100% penetrance. Significant disease components include primary myelofibrosis, leukemia, histiocytic sarcoma, and vasculitis. Xist-deficient hematopoietic stem cells (HSC) show aberrant maturation and age-dependent loss. Reconstitution experiments indicate that MPN/MDS and myelofibrosis are of hematopoietic rather than stromal origin. We propose that Xist loss results in X-reactivation and consequent genome-wide changes that lead to cancer, thereby causally linking the X-chromosome to cancer in mice. Thus, Xist RNA is not only required to maintain XCI but also suppresses cancer in vivo.
Xist RNA is a potent suppressor of hematologic cancer in mice.
Sex, Age, Specimen part
View SamplesPurpose: We performed RNA-Immunoprecipitation in Tandem (RIPiT) experiments against human Staufen1 (Stau1) to identify its precise RNA binding sites in a transcriptome-wide manner. To monitor the consequences of Stau1 binding in terms of target mRNA levels and ribosome occupancy, we modified the levels of endogenous Stau1 in cells by siRNA or overexpression and performed RNA-sequencing and ribosome-footprinting experiments. Staufen1 (Stau1) is a double-stranded RNA (dsRNA) binding protein implicated in mRNA transport, regulation of translation, mRNA decay and stress granule homeostasis. Here we combined RNA-Immunoprecipitation in Tandem (RIPiT) with RNase footprinting, formaldehyde crosslinking, sonication-mediated RNA fragmentation and deep sequencing to map Staufen1 binding sites transcriptome-wide. We find that Stau1 binds complex secondary structures containing multiple short helices, many of which are formed by inverted Alu elements in annotated 3''UTRs or in "strongly distal" 3''UTRs extending far beyond the canonical polyadenylation signal. Stau1 also interacts with both actively translating ribosomes and with mRNA coding sequences (CDS) and 3''UTRs in proportion to their GC-content and internal secondary structure-forming propensity. On mRNAs with high CDS GC-content, higher Stau1 levels lead to greater ribosome densities, suggesting a general role for Stau1 in modulating the ability of ribosomes to elongate through secondary structures located in CDS regions. Overall design: We used HEK293 cells expressing near endogenous levels of wild-type Flag-Stau1 (65KDa isoform with an N-Terminal Flag tag). As a control we used a mutant version of Stau1 that is not functional for dsRNA binding. Formaldehyde crosslinking experiments and RNase footprinting experiments were done in two biological replicates. All RNASeq, Ribosome footprinting and PAS-Seq were done in two biological replicates.
Staufen1 senses overall transcript secondary structure to regulate translation.
No sample metadata fields
View SamplesWe have used surgical specimens to perform a differential analysis of the transcriptome of human retinal tissues following detachment.
Transcriptomic analysis of human retinal detachment reveals both inflammatory response and photoreceptor death.
Subject
View SamplesCancer stem cells (CSCs) have been reported in various cancers including skin squamous cell carcinoma (SCC). The molecular mechanisms regulating tumour initiation and stemness are still poorly characterized. Here, we found that Sox2, a transcription factor expressed in various types of embryonic and adult stem cells (SCs), was the most upregulated transcription factor in CSCs of squamous skin tumours. Sox2 is absent in normal epidermis and begins to be expressed in the vast majority of mouse and human pre-neoplastic skin tumours and continues to be expressed in a heterogeneous manner in invasive mouse and human SCCs. In contrast to other SCCs, in which Sox2 is frequently genetically amplified, the expression of Sox2 in mouse and human skin SCCs is transcriptionally regulated. Conditional deletion of Sox2 in the mouse epidermis dramatically decreases skin tumour formation following chemical induced carcinogenesis. Using Sox2-GFP knockin mice, we showed that Sox2 expressing cells in invasive SCC are greatly enriched in tumour propagating cells (TPCs) that further increase upon serial transplantations. Lineage ablation of Sox2 expressing cells within primary benign and malignant SCCs leads to tumour regression, consistent with the critical role of Sox2 expressing cells in tumour maintenance. Conditional Sox2 deletion in pre-existing skin papilloma and SCC leads to their regression and decreases their ability to be propagated upon transplantation into immunodeficient mice, supporting the essential role of Sox2 in regulating CSC functions. Transcriptional profiling of Sox2-GFP expressing CSC and upon Sox2 deletion uncovered a gene network regulated by Sox2 in primary tumour cells in vivo. Chromatin immunoprecipitation identified several direct Sox2 target genes controlling tumour stemness, survival, proliferation, adhesion, invasion, and paraneoplastic syndrome. Altogether, our study demonstrates that Sox2, by marking and regulating the functions of skin tumour initiating cells and CSCs, establishes a continuum between tumour initiation and progression in primary skin tumours.
SOX2 controls tumour initiation and cancer stem-cell functions in squamous-cell carcinoma.
No sample metadata fields
View SamplesThe purpose of this study was to identify putative downstream targets of the transcription factor ZIC2 in the mouse embryo. The results indicate loss of NODAL pathway expression, consistent with the observed phenotype of right isomerism in heart, lungs and viscera.
A Requirement for Zic2 in the Regulation of Nodal Expression Underlies the Establishment of Left-Sided Identity.
Specimen part
View SamplesCancer stem cells (CSCs) have been reported in various cancers including skin squamous cell carcinoma (SCC). The molecular mechanisms regulating tumour initiation and stemness are still poorly characterized. Here, we found that Sox2, a transcription factor expressed in various types of embryonic and adult stem cells (SCs), was the most upregulated transcription factor in CSCs of squamous skin tumours. Sox2 is absent in normal epidermis and begins to be expressed in the vast majority of mouse and human pre-neoplastic skin tumours and continues to be expressed in a heterogeneous manner in invasive mouse and human SCCs. In contrast to other SCCs, in which Sox2 is frequently genetically amplified, the expression of Sox2 in mouse and human skin SCCs is transcriptionally regulated. Conditional deletion of Sox2 in the mouse epidermis dramatically decreases skin tumour formation following chemical induced carcinogenesis. Using Sox2-GFP knockin mice, we showed that Sox2 expressing cells in invasive SCC are greatly enriched in tumour propagating cells (TPCs) that further increase upon serial transplantations. Lineage ablation of Sox2 expressing cells within primary benign and malignant SCCs leads to tumour regression, consistent with the critical role of Sox2 expressing cells in tumour maintenance. Conditional Sox2 deletion in pre-existing skin papilloma and SCC leads to their regression and decreases their ability to be propagated upon transplantation into immunodeficient mice, supporting the essential role of Sox2 in regulating CSC functions. Transcriptional profiling of Sox2-GFP expressing CSC and upon Sox2 deletion uncovered a gene network regulated by Sox2 in primary tumour cells in vivo. Chromatin immunoprecipitation identified several direct Sox2 target genes controlling tumour stemness, survival, proliferation, adhesion, invasion, and paraneoplastic syndrome. Altogether, our study demonstrates that Sox2, by marking and regulating the functions of skin tumour initiating cells and CSCs, establishes a continuum between tumour initiation and progression in primary skin tumours.
SOX2 controls tumour initiation and cancer stem-cell functions in squamous-cell carcinoma.
Specimen part
View SamplesDetermination of the mechanism by which microglia regulate growth of brain tumor initiating cells (BTICs) and differentiation. Results identify the factors involved in the regulation and provide mechanistic basis.
Therapeutic activation of macrophages and microglia to suppress brain tumor-initiating cells.
Cell line
View SamplesHere, we show that functional loss of a single gene is sufficient to confer constitutive milk protein production and protection against mammary tumor formation. Caveolin-3 (Cav-3), a muscle-specific caveolin-related gene, is highly expressed in striated and smooth muscle cells. We demonstrate that Cav-3 is also expressed in myoepithelial cells within the mammary gland. To determine if genetic ablation of Cav-3 expression affects adult mammary gland development, we next studied the phenotype(s) of Cav-3 (-/-) null mice. Interestingly, detailed analysis of Cav-3 (-/-) virgin mammary glands shows dramatic increases in ductal thickness, side-branching, and the development of extensive lobulo-alveolar hyperplasia, akin to the changes normally observed during pregnancy and lactation. Analysis by genome-wide expression profiling reveals the upregulation of gene transcripts associated with pregnancy/lactation, mammary stem cells, and human breast cancers, consistent with a constitutive lactogenic phenotype. The expression levels of three key transcriptional regulators of lactation, namely Elf5, Stat5a, and c-Myc are also significantly elevated. Experiments with pregnant mice directly show that Cav-3 (-/-) mice undergo precocious lactation. Finally, using orthotopic implantation of a transformed mammary cell line (known as Met-1), we demonstrate that virgin Cav-3 (-/-) mice are dramatically protected against mammary tumor formation. Interestingly, Cav-3 (+/-) mice also show similar protection, indicating that even reductions in Cav-3 levels are sufficient to render these mice resistant to tumorigenesis. Thus, Cav-3 (-/-) mice are a novel preclinical model to study the protective effects of a constitutive lactogenic microenviroment on mammary tumor onset and progression. Our current studies have broad implications for using the lactogenic micro-environment as a paradigm to discover new therapies for the prevention and/or treatment of human breast cancers. Most importantly, a lactation-based therapeutic strategy would provide a more natural and nontoxic approach to the development of novel anti-cancer therapies.
Loss of caveolin-3 induces a lactogenic microenvironment that is protective against mammary tumor formation.
No sample metadata fields
View SamplesThe Gata4 transcription factor is essential for normal heart development, but the molecular basis for its function remain poorly understood. We profiled at the whole genome level transcript changes in cardiomyocytes when Gata4 is depleted from zebrafish embryos. Our objective was to elucidate the cardiomyocyte-specific molecular program functioning downstream of Gata4 in order to better understand the role of Gata4 in cardiac morphogenesis. Overall design: Six samples in total are deposited. Three replicate control samples and three replicate Gata4 morphant samples were analyzed.
Small heat shock proteins Hspb7 and Hspb12 regulate early steps of cardiac morphogenesis.
No sample metadata fields
View SamplesLysozyme-GFP ER-HoxA9 cells were cultured in the presence of estradiol (active ER-HoxA9) or in the absence of estradiol (inactive ER-HoxA9). Samples were taken at 10 time points over a 120 hour time course of myeloid differentiation to examine those gene expression changes that accompany differentiation upon the release of HoxA9 differentiation arrest. Overall design: RNA Sequencing at 10 different time points done in duplicate
Inhibition of Dihydroorotate Dehydrogenase Overcomes Differentiation Blockade in Acute Myeloid Leukemia.
Cell line, Subject
View Samples