The genetic programs that promote retention of self-renewing leukemia stem cells (LSCs) at the apex of cellular hierarchies in acute myeloid leukemia (AML) are not known. In a mouse model of human AML, LSCs exhibit variable frequencies that correlate with the initiating MLL oncogene and are maintained in a self-renewing state by a transcriptional sub-program more akin to that of embryonic stem cells (ESCs) than adult stem cells. The transcription/chromatin regulatory factors Myb, Hmgb3 and Cbx5 are critical components of the program and suffice for Hoxa/Meis-independent immortalization of myeloid progenitors when co-expressed, establishing the cooperative and essential role of an ESC-like LSC maintenance program ancillary to the leukemia initiating MLL/Hox/Meis program. Enriched expression of LSC maintenance and ESC-like program genes in normal myeloid progenitors and poor prognosis human malignancies links the frequency of aberrantly self-renewing progenitor-like cancer stem cells to prognosis in human cancer.
Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells.
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View SamplesNormal myeloid lineage cell populations (C57BL/6 mice, aged 4-10 weeks, male or female) with three distinct immunophenotypes were prospectively isolated and characterized. In preparation for FACS sorting, bone marrow cells were separated into c-kit+ and c-kit- fractions using an AutoMACS device. C-kit+ cells were further fractionated based on Gr1 and Mac1 expression, and absence of lineage antigen expression (B220, TER119, CD3, CD4, CD8 and IL7R), by cell sorting. C-kit+ Gr1+ Mac1lo/- and c-kit+ Gr1+ Mac1+ displayed cytologic features of undifferentiated hematopoietic cells or myeloblasts, whereas c-kit- Gr1+ Mac1+ cells were mature neutrophils.
Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells.
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View SamplesLeukemia cells from mice with MLL-AF10 AML were fractionated into separate sub-populations on the basis of c-kit expression, which correlates with MLL LSC frequency (Somervaille and Cleary, 2006). The sorted AML sub-populations exhibited substantial differences in their frequencies of AML CFCs/LSCs (mean 14-fold) and morphologic features, consistent with a leukemia cell hierarchy with maturation through to terminally differentiated neutrophils.
Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells.
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View SamplesZebrafish have the remarkable ability to regenerate body parts including the heart, spinal cord and fins by a process referred to as epimorphic regeneration. Recent studies have illustrated that similar to adult zebrafish, early life stage-larvae also possess the ability to regenerate the caudal fin. A comparative genomic analysis was used to determine the degree of conservation in gene expression among the regenerating adult caudal fin, adult heart and larval fin. Results indicate that these tissues respond to amputation/injury with strikingly similar genomic responses. Comparative analysis revealed raldh2, a rate-limiting enzyme for the synthesis of Retinoic acid (RA), as one of the highly induced genes across the three regeneration platforms.
Comparative expression profiling reveals an essential role for raldh2 in epimorphic regeneration.
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View SamplesMost tumors are epithelial-derived, and although disruption of polarity and aberrant cellular junction formation is a poor prognosticator in human cancer, the role of polarity determinants in oncogenesis is poorly understood. Using in vivo selection, we identified a mammalian orthologue of the Drosophila polarity regulator crumbs as a gene whose loss of expression promotes tumor progression. Immortal baby mouse kidney epithelial (iBMK) cells selected in vivo to acquire tumorigenicity displayed dramatic repression of crumbs3 (crb3) expression associated with disruption of tight junction formation, apicobasal polarity, and contact-inhibited growth. Restoration of crb3 expression restored junctions, polarity and contact inhibition, while suppressing migration and metastasis. These findings suggest a role for mammalian polarity determinants in suppressing tumorigenesis that may be analogous to the well-studied polarity tumor suppressor mechanisms in Drosophila.
Role of the polarity determinant crumbs in suppressing mammalian epithelial tumor progression.
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View SamplesThe aim of this study was to determine the effect of transgenic Aire expression on the transcriptional profile of a tissue that normally does not express Aire: pancreatic islets. The transcriptional profile of transgenic RIP-Aire27 islets was compared to non-transgenic littermate islets as well as to archival NOD thymic medullary epithelial cells (MEC) data. All data were from non-obese diabetic (NOD) mice
Transcriptional impact of Aire varies with cell type.
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View SamplesIL-1R-associated kinases (IRAKs) participate in Toll-like receptor (TLR) signal transduction. MALP-2 is a TLR2 ligand, and stimulation of macrophages with MALP-2 activates expression of various genes including proinflammatory cytokines.
Sequential control of Toll-like receptor-dependent responses by IRAK1 and IRAK2.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Microcephaly gene links trithorax and REST/NRSF to control neural stem cell proliferation and differentiation.
Time
View SamplesBackground: Microvascular injury and increased vascular leakage are prominent features of the radiation-induced lung injury (RILI) which follows cancerassociated thoracic irradiation. The mechanisms of RILI are incompletely understood and therapeutic strategies to limit RILI are currently unavailable. We established a murine model of radiation pneumonitis in order to assess mechanism-based therapies for RILI-induced inflammation and vascular barrier dysfunction. Based on prior studies, we investigated the therapeutic potential of simvastatin as a vascular barrier protective agent in RILI.
Simvastatin attenuates radiation-induced murine lung injury and dysregulated lung gene expression.
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View SamplesPolarization of macrophages to M1 or M2 cells is important for mounting responses against bacterial and helminth infection respectively. Jumonji domain containing 3 (JMJD3), a histone 3 K27 demethylase, has been implicated in the activation of macrophages. Here we show that JMJD3 is essential for M2 macrophage polarization to helminth infection and chitin, though JMJD3 is dispensable for M1 responses. Furthermore, Jmjd3 is critical for proper bone marrow macrophage differentiation in a demethylase activity-dependent manner. Jmjd3 deficiency affected trimethylation of H3K27 in only a limited numbers of genes. Among them, we identified Irf4 as the target transcription factor critical for controlling M2 macrophage polarization. Collectively, these results show that JMJD3-mediated H3K27 demethylation is critical for regulating M2 macrophage development leading to anti-helminth host responses.
The Jmjd3-Irf4 axis regulates M2 macrophage polarization and host responses against helminth infection.
Specimen part, Treatment
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