MEG3 (Maternally Expressed Gene 3) is a non-coding RNA that is highly expressed in the normal human brain and pituitary. Expression of MEG3 is lost in gonadotroph-derived clinically non-functioning pituitary adenomas. Meg3 knock-out mice were generated to identify targets and potential functions of this gene in embryonic development and tumorigenesis. Gene expression profiles were compared in the brains of Meg3-null embryos and wild-type litter-mate controls using microarray analysis. Microarray data were analyzed with GeneSifter which uses Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) classifications to identify signaling cascades and functional categories of interest within the data set. Differences were found in signaling pathways and ontologies related to angiogenesis between wild-type and knock-out embryos. Quantitative RT-PCR and histological staining showed increased expression of some VEGF pathway genes and increased cortical microvessel density in the knock-out embryos. These results are consistent with reported increases in VEGF signaling observed in human clinically non-functioning pituitary adenomas. In conclusion, Meg3 may play an important role in control of vascularization in the brain and may function as a tumor suppressor by preventing angiogenesis.
Increased expression of angiogenic genes in the brains of mouse meg3-null embryos.
Specimen part
View SamplesWe determined whole genome expression changes in 2 migratory cell lines that were derived from a parent HCC cell line.
A novel KLF6-Rho GTPase axis regulates hepatocellular carcinoma cell migration and dissemination.
Specimen part, Cell line
View SamplesThese data are from the brains (amygdala and hippocampus) of mice originally derived from a cross between C57BL/6J and DBA/2J inbred strains. We used short-term selection to produce outbred mouse lines with differences in contextual fear conditioning, which is a measure of fear learning. We selected for a total of 4 generations. Fear learning differed in the selected lines and this difference was stronger with each successive generation of selection. These mice also showed differences for measures of anxiety-like behavior, but were not different for tests of non-fear motivated learning, suggesting that selection altered alleles that are specifically involved in emotional behaviors. We identified several QTLs for the selection response. We used Affymetrix microarrays to identify differentially expressed genes in the amygdala and hippocampus of mice from the final generation of selection. Amygdala and hippocampus samples were rapidly dissected out of experimentally nave mice f rom each selected line. Three samples were pooled and hybridized to each array. Experimentally nave mice were used because the behavior of the mice can be reliably anticipated due to their lineage. Thus, these gene expression differences are not due to the response to human handling, foot shock or fear-inducing conditioned stimuli. We have a second similar study that focuses on a different selected population that was based on C57BL/6J and A/J mice (see GES4034).
Selection for contextual fear conditioning affects anxiety-like behaviors and gene expression.
No sample metadata fields
View SamplesDendritic cells (DC) develop from hematopoietic stem cells, which is guided by instructive signals through cytokines. DC development progresses from multipotent progenitors (MPP) via common DC progenitors (CDP) into DC. Flt3 ligand (Flt3L) signaling via the Flt3/Stat3 pathway is of pivotal importance for DC development under steady state conditions. Additional factors produced during steady state or inflammation, such as TGF-beta1 or GM-CSF, also influence the differentiation potential of MPP and CDP. Here, we studied how gp130, GM-CSF and TGF-beta1 signaling influence DC lineage commitment from MPP to CDP and further into DC. We observed that activation of gp130 signaling promotes expansion of MPP. Additionally, gp130 signaling inhibited Flt3L-driven DC differentiation, but had little effect on GM-CSF-driven DC development. The inflammatory cytokine GM-CSF induces differentiation of MPP into inflammatory DC and blocks steady state DC development. Global transcriptome analysis revealed a GM-CSF-driven gene expression repertoire that primes MPP for differentiation into inflammatory DC. Finally, TGF-beta1 induces expression of DC-lineage affiliated genes in MPP, including Flt3, Irf-4 and Irf-8. Under inflammatory conditions, however, the effect of TGF- beta1 is altered: Flt3 is not upregulated, indicating that an inflammatory environment inhibits steady state DC development. Altogether, our data indicate that distinct cytokine signals produced during steady state or inflammation have a different outcome on DC lineage commitment and differentiation.
Dendritic cell lineage commitment is instructed by distinct cytokine signals.
Specimen part, Treatment
View SamplesCellular signal transduction is governed by multiple feedback mechanisms to elicit robust cellular decisions. We combined mathematical modeling and extensive time-resolved data sets in primary erythroid progenitor cells and dissected the roles of the two transcriptional feedback regulators of the SOCS family, CIS and SOCS3 in JAK2/STAT5 signaling. Our model revealed that both feedbacks are most effective at different ligand concentration ranges.
Division of labor by dual feedback regulators controls JAK2/STAT5 signaling over broad ligand range.
Specimen part
View SamplesActivation of the canonical Wnt signaling pathway is commonly observed in pancreatic cancer. We therefore sought to identify a gene expression profile associated with the activation of this pathway in pancreatic cancer cells.
Activation of WNT/β-Catenin Signaling Enhances Pancreatic Cancer Development and the Malignant Potential Via Up-regulation of Cyr61.
Specimen part, Cell line
View SamplesKnockdown of the transcription factor PU.1 (Spi1) leads to acute myeloid leukemia (AML) in mice. We examined the transcriptome of PU.1 knockdown hematopoietic stem cells (HSC) in the preleukemic phase by linear amplification and genome-wide array analysis to identify transcriptional changes preceding malignant transformation. Hierarchical cluster analysis and principal component analysis clearly distinguished PU.1 knockdown from wildtype HSC. Jun family transcription factors c-Jun and JunB were among the top downregulated targets. Retroviral restoration of c-Jun expression in bone marrow cells of preleukemic mice partially rescued the PU.1-initiated myelomonocytic differentiation block. Lentiviral restoration of JunB at the leukemic stage led to reduced clonogenic growth, loss of leukemic self-renewal capacity, and prevented leukemia in transplanted NOD-SCID mice. Examination of 305 AML patients confirmed the correlation between PU.1 and JunB downregulation and suggests its relevance in human disease. These results delineate a transcriptional pattern that precedes the leukemic transformation in PU.1 knockdown HSC and demonstrate that decreased levels of c-Jun and JunB contribute to the development of PU.1-induced AML by blocking differentiation (c-Jun) and increasing self-renewal (JunB). Therefore, examination of disturbed gene expression in HSC can identify genes whose dysregulation is essential for leukemic stem cell function and are targets for therapeutic interventions.
Essential role of Jun family transcription factors in PU.1 knockdown-induced leukemic stem cells.
No sample metadata fields
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
View Samples