Polycomb protein group (PcG)-dependent trimethylation on H3-K27(H3K27me3) regulates identity of embryonic stem cells (SCs). How H3K27me3 governs adult SCs and tissue development is unclear. Here, we conditionally target H3-K27-methyltransferases Ezh2 and Ezh1 to address their roles in mouse skin homeostasis. Postnatal phenotypes appear only in doubly-targeted skin, where H3K27me3 is abolished, revealing functional redundancy in EZH1/2 proteins. Surprisingly, while Ezh1/2-null hair follicles (HFs) arrest morphogenesis and degenerate due to defective proliferation and increased apoptosis, epidermis hyperproliferates and survives engraftment. mRNA-microarray studies reveal that despite these striking phenotypic differences, similar genes are upregulated in HF and epidermal Ezh1/2-null progenitors. Featured prominently are a) PcG-controlled non-skin lineage genes, whose expression is still significantly lower than in native tissues, and b) the PcG-regulated Ink4a/Inkb/Arf locus. Interestingly, even though Ink4a/Arf/Ink4b genes are fully activated in HF cells, they only partially so in epidermal-progenitors. Importantly, transduction of Ink4b/Ink4a/Arf shRNAs restores proliferation/survival of Ezh1/2-null HF progenitors in vitro, pointing towards the relevance of this locus to the observed HF phenotypes. Our findings reveal new insights into Polycomb-dependent tissue control and provide a new twist to how different progenitors within one tissue respond to loss of H3K27me3.
EZH1 and EZH2 cogovern histone H3K27 trimethylation and are essential for hair follicle homeostasis and wound repair.
Sex, Age, Specimen part
View SamplesNOD mice are an inbred strain that display enhanced MZ B cell differentiation from an early age. Interestingly, several lines of evidence implicate MZ B cells in this strain as important contributors to the T cell mediated beta cell destruction associated with the development of type 1 diabetes (T1D). In order to develop a better understanding of the underlying causes for augmented MZ B cell production in NOD mice, we obtained the transcriptional profiles of FO and MZ subsets and TR precursors from NOD mice and compared them to those of the B6 strain.
Intrinsic molecular factors cause aberrant expansion of the splenic marginal zone B cell population in nonobese diabetic mice.
Sex, Age, Specimen part
View SamplesUsing EphB2 or the ISC marker Lgr5, we have FACS-purified and profiled intestinal stem cells (ISCs), crypt proliferative progenitors and late transient amplifying cells to define a gene expression program specific for normal ISCs.
The intestinal stem cell signature identifies colorectal cancer stem cells and predicts disease relapse.
Specimen part
View SamplesMicroRNAs have emerged as major genetic elements in the genesis and suppression of cancer. Here, multi-dimensional cancer genome analysis and validation has defined a novel Glioblastoma Multiforme (GBM) tumor suppressor pathway and mechanism of action centered on Quaking (QK), a member of the STAR family of RNA-binding proteins. Combined functional, biochemical and computational studies establish that p53 directly regulates QK gene expression, QK protein binds and stabilizes miR-20a of the cancer-relevant miR-17-92 cluster, and miR-20a in turn functions to regulate TGFR2 and the TGF signaling network. Linkage of these pathway components is supported by their genome and expression status across GBM specimens and by their gain- and loss-of-function interactions in in vitro and in vivo complementation studies. This p53-QK-miR-20a axis expands our understanding of the p53 tumor suppression network in cancer and reveals a novel tumor suppression mechanism involving regulation of specific cancer-relevant microRNAs.
STAR RNA-binding protein Quaking suppresses cancer via stabilization of specific miRNA.
Specimen part, Cell line
View SamplesIdentify potential QK-regulated mRNAs and linked pathways by comparing the transcriptional profiles of shGFP- and shQK-transduced Ink4a/Arf-/- Pten-/- primary mouse astrocytes
STAR RNA-binding protein Quaking suppresses cancer via stabilization of specific miRNA.
No sample metadata fields
View SamplesIdentify potential miR-20a regulated mRNAs and linked pathways in the setting of QK knockdown by comparing the transcriptional profiles of shQK-transduced primary mouse Ink4a/Arf-/- Pten-/- astrocytes together with miR-20a or a scrambled miRNA control (miR-NT)
STAR RNA-binding protein Quaking suppresses cancer via stabilization of specific miRNA.
No sample metadata fields
View SamplesThe transcription factor STAT5 plays a critical role in B cell acute lymphoblastic leukemia (B-ALL). How STAT5 mediates this effect is unclear. Here we demonstrate that STAT5 activation cooperates with defects in the pre-BCR signaling components encoded by Blnk, Btk, Prkcb, Nfkb1, and Ikzf1 to initiate B-ALL. STAT5 antagonizes NF-B and IKAROS by opposing regulation of shared target genes. STAT5 binding was enriched at super-enhancers, which were associated with an opposing network of transcription factors, including PAX5, EBF1, PU.1, IRF4, and IKAROS. Patients with high ratios of active STAT5 to NF-B or IKAROS have more aggressive disease. Our studies illustrate that an imbalance of two opposing transcriptional programs drive B-ALL, and suggest that restoring the balance of these pathways may inhibit B-ALL.
Antagonism of B cell enhancer networks by STAT5 drives leukemia and poor patient survival.
No sample metadata fields
View SamplesOvarian cancer is one of the most deadly cancers accounting for only 3% of diagnosed cancers, but is the fifth leading cause of cancer deaths among woman; however, the progression of ovarian cancer is poorly understood. To study and further understand the early events that lead to epithelial derived ovarian cancer, we previously developed a cell model of progressive ovarian cancer. Mouse ovarian surface epithelial (MOSE) cells have undergone spontaneous transformation in cell culture and represent pre-neoplastic, non-tumorigenic to an aggressive malignant phenotype.
Changes in gene expression and cellular architecture in an ovarian cancer progression model.
Specimen part
View SamplesVinylidene Chloride has been widely used in the production of plastics and flame retardants. Exposure of B6C3F1 to VDC in the 2-year National Toxicology Program carcinogenicity bioassay resulted in a dose-dependent increase in renal cell hyperplasias, adenomas, and carcinomas (RCCs). Global gene expression analysis showed overrepresentation of pathways associated with chronic xenobiotic and oxidative stress in RCCs from VDC-exposed B6C3F1 mice, as well as cMyc overexpression and dysregulation of Tp53 cell cycle checkpoint and DNA damage repair pathways. Trend analysis comparing RCC, VDC-exposed kidney, and vehicle control kidney showed a conservation of pathway dysregulation in terms of overrepresentation of xenobiotic and oxidative stress, and DNA damage and cell cycle checkpoint pathways in both VDC-exposed kidney and RCC, suggesting that these mechanisms play a role in the development of RCC in VDC-exposed mice.
Renal Cell Carcinomas in Vinylidene Chloride-exposed Male B6C3F1 Mice Are Characterized by Oxidative Stress and TP53 Pathway Dysregulation.
Specimen part
View SamplesHepatocellular carcinoma (HCC) is an important cause of morbidity and mortality worldwide. Although the risk factors of human HCC are well known, the molecular characterization of this disease is complex, and treatment options in general remain poor. The use of rodent models to study human cancer has been extensively pursued both through genetically engineered rodents and rodent models used in carcinogenicity and toxicology studies. In particular, the B6C3F1 mouse used in the National Toxicology Program (NTP) 2-year bioassay has been used to evaluate the carcinogenic effects of environmental and occupational chemicals, and other compounds. The high incidence of spontaneous HCC in the B6C3F1 mouse has challenged its use as a model for chemically induced HCC in terms of relevance to the human disease. Using global gene expression profiling, we identify the dysregulation of several mediators similarly altered in human HCC, including re-expression of fetal oncogenes, upregulation of protooncogenes, downregulation of tumor suppressor genes, and abnormal expression of cell cycle mediators, growth factors, apoptosis regulators, and angiogenesis and extracellular matrix remodeling factors. Although important differences in etiology and pathogenesis remain between human and mouse HCC, there are important similarities in global gene expression and the types of signaling networks dysregulated in mouse and human HCC. These data provide further relevance for the use of this model in hazard identification of compounds with potential human carcinogenicity risk, and may help in better understanding mechanisms of tumorigenesis due to chemical exposure in the NTP 2-year carcinogenicity bioassay.
Global gene profiling of spontaneous hepatocellular carcinoma in B6C3F1 mice: similarities in the molecular landscape with human liver cancer.
Specimen part
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