MED23, a subunit of the Mediator coactivator complex, is important for the expression of a subset of MAPK/ERK pathway-dependent target genes; however, the genes in this subset varies between cell types. MAPK/ERK pathway-dependent processes are essential for T-cell development and function, but whether MED23 has a role in this context is unknown. We generated Med23 conditional knockout mice and induced Med23 deletion in early T cell development using the lineage specific Lck-Cre transgene. While the total cell number and distribution of cell populations in the thymuses of Med23flox/flox;Lck-Cre mice were essentially normal, MED23 null T-cells failed to efficiently populate the peripheral lymphoid organs. MED23 null thymocytes displayed decreased expression of the MAPK/ERK-responsive genes Egr1, Egr2, as well as of the membrane glycoprotein Cd52 (CAMPATH-1). MED23 null CD4 single-positive thymocytes also showed decreased expression of KLF2 (LKLF), a T cell master regulatory transcription factor. Indeed, similarities between the phenotypes of mice lacking MED23 or KLF2 in T-cells suggest that KLF2 deficiency in MED23 null T-cells is one of their key defects. Mechanistic experiments using MED23 null MEFs further suggest that MED23 is required for full activity of the MAPK-responsive transcription factor MEF2, which has previously been shown to mediate Klf2 expression. In summary, our data indicate that MED23 has critical roles in enabling T-cells to populate the peripheral lymphoid organs, possibly by potentiating MEF2-dependent expression of the T-cell transcription factor KLF2.
T-cells null for the MED23 subunit of mediator express decreased levels of KLF2 and inefficiently populate the peripheral lymphoid organs.
Sex, Specimen part
View SamplesIn order to identify the gene targets of frequently altered chromosomal regions in retinoblastoma, a meta-analysis of genome-wide copy number alterations studies on primary retinoblastoma tissue and retinoblastoma cell lines was performed. Published studies were complemented by copy number and gene expression analysis on primary and cell line samples of retinoblastoma. This dataset includes the gene expression data of the retinoblastoma cell lines
A Meta-Analysis of Retinoblastoma Copy Numbers Refines the List of Possible Driver Genes Involved in Tumor Progression.
Specimen part, Cell line
View SamplesPurpose: We applied cDNA molecule counting using unique molecular identifiers combined with high-throughput sequencing to study the transcriptome of individual mouse embryonic stem cells, with spike-in controls to monitor technical performance. We further examined transcriptional noise in the embryonic stem cells. Overall design: One 96-well plate of single-stranded cDNA libraries generated from 96 single R1 mouse embryonic stem cells sequenced on two lanes, and one 96-well plate of the same libraries further amplified by 9 PCR cycles sequenced on one lane.
Quantitative single-cell RNA-seq with unique molecular identifiers.
No sample metadata fields
View SamplesIn high income countries 90% of the patients achieve complete remission after induction chemotherapy. However, 30-40% of these patients suffer from relapse. These patients face a dismal prognosis, as the majority (>60%) of relapsed patients die within 5 years. As a result, outcome for pediatric acute myeloid leukemia (AML) patients remains poor and has stabilized over the past 15 years. To prevent or better treat relapse of AML is the best option to improve outcome. Despite patient specific differences, most patients do respond to initial therapy. This suggests that at relapse, mechanisms are active that cause the altered response to chemotherapy. Detailed understanding of mechanisms that cause relapse remain largely elusive. To gain insight in the molecular pathways that characterize relapsed AML, we performed genome wide gene expression profiling on paired initial diagnosis and relapsed AML samples of 23 pediatric AML patients. We used pathway analysis to find which molecular pathways are involved in altered gene expression between diagnosis and relapse samples of individual AML patients.
Gene expression profiles associated with pediatric relapsed AML.
Disease
View SamplesHigh VEGFC mRNA expression of AML blasts is related to increased in vitro and in vivo drug resistance. The prognostic significance of VEGFC on long-term outcome and its associated gene expression profiles remain to be defined. We studied the effect of VEGFC on treatment outcome and investigated gene expression profiles associated with VEGFC using microarray data of 525 adult and 100 pediatric AML patients. High VEGFC expression appeared strongly associated with reduced complete remission rate, reduced overall and event-free survival (OS and EFS) in adult AML. Multivariable analysis established high VEGFC as prognostic indicator independent of cytogenetic risk, FLT3-ITD, NPM1, CEBPA, age and WBC. Also in pediatric AML high VEGFC was related to reduced OS. A unique series of differentially expressed genes was identified that distinguished AML with high VEGFC from AML with low VEGFC, i.e., 331 upregulated genes (representative of proliferation, VEGF-receptor activity, signal transduction) and 44 downregulated genes (e.g. related to apoptosis) consistent with a role in enhanced chemoresistance. In conclusion, high VEGFC predicts adverse long-term prognosis and provides prognostic information in addition to well-known prognostic factors.
High VEGFC expression is associated with unique gene expression profiles and predicts adverse prognosis in pediatric and adult acute myeloid leukemia.
Specimen part, Subject
View SamplesBackground
Loss of photoreceptorness and gain of genomic alterations in retinoblastoma reveal tumor progression.
Specimen part
View SamplesDectin1 controls the recruitment of TLR9 to -1,3 glucan beads containing phagosomes. We sought to determine whether Dectin-1 also plays a role in controlling TLR9 dependent gene expression.
Dectin-1 Controls TLR9 Trafficking to Phagosomes Containing β-1,3 Glucan.
Specimen part
View SamplesWe analyzed the transcriptional profile of colon and small-intestinal (SI) tissues in response to ex-vivo colonization with members of the gut microbiota. Tissues were dissected from SPF or GF mice, and connected to the ex-vivo gut organ culture system. Then, microbial cultures or fecal samples were infused into the lumen, and tissues were processed in different time points, as indicated below.
An Intestinal Organ Culture System Uncovers a Role for the Nervous System in Microbe-Immune Crosstalk.
Sex, Age
View SamplesIndividuals with Down syndrome (DS) are predisposed to develop acute megakaryoblastic leukemia (AMKL), characterized by expression of truncated GATA1 transcription factor protein (GATA1s) due to somatic mutation. The treatment outcome for DS-AMKL is more favorable than for AMKL in non-DS patients. To gain insight into gene expression differences in AMKL, we compared 24 DS and 39 non-DS AMKL samples. We found that non-DS-AMKL samples cluster in two groups, characterized by differences in expression of HOX/TALE family members. Both of these groups are distinct from DS-AMKL, independent of chromosome 21 gene expression. To explore alterations of the GATA1 transcriptome, we used cross-species comparison with genes regulated by GATA1 expression in murine erythroid precursors. Genes repressed after GATA1 induction in the murine system, most notably GATA-2, MYC, and KIT, show increased expression in DS-AMKL, suggesting that GATA1s fail to repress this class of genes. Only a subset of genes that are up-regulated upon GATA1 induction in the murine system show increased expression in DS-AMKL, including GATA1 and BACH1, a probable negative regulator of megakaryocytic differentiation located on chromosome 21. Surprisingly, expression of the chromosome 21 gene RUNX1, a known regulator of megakaryopoiesis, was not elevated in DS-AMKL. Our results identify relevant signatures for distinct AMKL entities and provide insight into gene expression changes associated with these related leukemias.
Identification of distinct molecular phenotypes in acute megakaryoblastic leukemia by gene expression profiling.
Sex, Age
View SamplesWithin the human gut reside diverse microbes coexisting with the host in a mutually advantageous relationship. We comprehensively identified the modulatory effects of phylogenetically diverse human gut microbes on the murine intestinal transcriptome. Gene-expression profiles were generated from the whole-tissue intestinal RNA of mice colonized with various single microbial strains. The selection of microbe-specific effects, from the transcriptional response, yielded only a small number of transcripts, indicating that symbiotic microbes have only limited effects on the gut transcriptome overall. Moreover, none of these microbe-specific transcripts was uniformly induced by all microbes. Interestingly, these responsive transcripts were induced by some microbes but repressed by others, suggesting different microbes can have diametrically opposed consequences.
Mining the Human Gut Microbiota for Immunomodulatory Organisms.
Sex, Age, Specimen part
View Samples