Medulloblastoma (MB) is the most common malignant primary pediatric brain tumor and is currently divided into 4 subtypes based on different genomic alterations, gene expression profiles and response to treatment: WNT, Sonic Hedgehog (SHH), Group 3 and Group 4. The extensive heterogeneity has made it difficult to assess the relevance of genes to malignant progression. For example, expression of the transcription factor, OTX2, is frequently dysregulated in multiple MB variants; however, it's role may be subtype specific. Here, we utilized human embryonic stem cell-derived neural precursors to determine the role of OTX2 in MB tumor progression using gain and loss of function studies.
OTX2 exhibits cell-context-dependent effects on cellular and molecular properties of human embryonic neural precursors and medulloblastoma cells.
Specimen part
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Characterization of a novel OTX2-driven stem cell program in Group 3 and Group 4 medulloblastoma.
Cell line
View SamplesMedulloblastoma (MB) is the most common malignant primary pediatric brain cancer. Among the most aggressive subtypes, Group 3 and Group 4 originate from stem/progenitor cells, frequently metastasize, and often display the worst prognosis, yet, as the names imply, we know the least about the molecular mechanisms driving their progression. Here, we show that the transcription factor orthodenticle homeobox 2 (OTX2) promotes self-renewal while inhibiting differentiation in vitro and increases tumor-initiating capacity from MB stem cell populations in vivo. Characterization of the OTX2 regulatory network revealed a novel relationship between OTX2 and genes associated with multiple axon guidance signaling pathways in Group 3 and Group 4 MB stem/progenitor cells. In particular, OTX2 levels were negatively correlated with semaphorin (SEMA) signaling, as expression of 9 SEMA pathway genes is upregulated following OTX2 knockdown with some being potential direct OTX2 targets. Importantly, this negative correlation between OTX2 and SEMA pathway genes was also observed in patient samples, with lower expression of SEMA4D associated with poor outcome in Group 3 and 4 tumors. Functional studies using established and newly derived MB cell lines demonstrated that increased levels of SEMA pathway genes are associated with decreased self-renewal and growth, and that RHO signaling, known to mediate the effects of SEMA genes, is contributing to the OTX2 KD phenotype. Our study provides critical mechanistic insight into the networks controlled by OTX2 in self-renewing MB cells and reveals novel roles for axon guidance genes and their downstream effectors as putative tumor suppressors and therapeutic targets in Group 3 and Group 4 MB.
Characterization of a novel OTX2-driven stem cell program in Group 3 and Group 4 medulloblastoma.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Chronic mucocutaneous candidiasis and connective tissue disorder in humans with impaired JNK1-dependent responses to IL-17A/F and TGF-β.
Specimen part, Disease, Disease stage, Treatment, Time
View SamplesPrecise localization of the histone H3 variant CENP-A(Cse4) to centromeres is essential for accurate chromosome segregation. In budding yeast, CENP-A(Cse4) is regulated by ubiquitin-mediated proteolysis to ensure its exclusive localization to the centromere. Overexpression of CENP-A(Cse4) is lethal when the CENP-A(Cse4) E3 ubiquitin ligase, Psh1, is deleted. CENP-A(Cse4) mislocalizes to promoters in this condition, so we investigated if there was an effect on gene expression of downstream genes using RNA-seq. Overall design: RNA-seq from two or three biological replicates each, at t0 and t2 hours after adding galactose for each of 6 experimental genotypes.
Regulation of Budding Yeast CENP-A levels Prevents Misincorporation at Promoter Nucleosomes and Transcriptional Defects.
Subject, Time
View SamplesEngineered abiotic stress resistance is an important target for increasing agricultural productivity.There are concerns, however, regarding possible ecological impacts of transgenic crops. In contrast to the first wave of transgenic crops, many abiotic stress resistance genes can initiate
Comparison of salt stress resistance genes in transgenic Arabidopsis thaliana indicates that extent of transcriptomic change may not predict secondary phenotypic or fitness effects.
Age, Specimen part, Treatment
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Cross-study homogeneity of psoriasis gene expression in skin across a large expression range.
Sex, Specimen part, Time
View SamplescDNA and cRNA hybridization technologies have different, probe-specific sensitivities. We used samples from an etanercept trial (GSE11903) to explore in a real-life setting the uniqueness of each platform.
Cross-study homogeneity of psoriasis gene expression in skin across a large expression range.
Specimen part, Time
View SamplesTo explore the psoriasis phenotype and pathways involved in psoriasis, we characterized gene expression in lesional and non-lesional skin from psoriasis patients.
Cross-study homogeneity of psoriasis gene expression in skin across a large expression range.
Specimen part
View SamplesTo explore the psoriasis phenotype, we characterize gene expression in lesional and non-lesional skin from psoriasis patients.
Cross-study homogeneity of psoriasis gene expression in skin across a large expression range.
Sex, Specimen part
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