The goal of this study is to uncover the changes in the transcriptome of sensory neurons of the liver kinase B1 (LKB1) knockout
Regulation of axonal morphogenesis by the mitochondrial protein Efhd1.
Specimen part
View SamplesAcute lymphoblastic leukaemia with early T-cell precursor immunophenotype (ETP ALL) is a highly aggressive subtype of ALL of unknown aetiology. To gain insights into the genetic basis of this disease, we performed whole genome sequencing of tumour and normal DNA of 12 children with ETP ALL. Analysis of structural and sequence variants in this discovery cohort, and mutation recurrence screening in a panel of 51 ETP and 43 non ETP ALL samples identified a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling, including IL7R, NRAS, KRAS, FLT3, BRAF, JAK1 and JAK3 in ETP ALL. Moreover, we identified multiple new targets of mutation in including GATA3, EP300, RUNX1, DNM2, ECT2L, HNRNPA1 and HNRNPR, as well as genes known to be mutated in T-ALL, including NOTCH1, PHF6, and WT1.. Five of 12 ETP ALL cases harboured novel chromosomal translocations, several of which accompanied complex multichromosomal rearrangements and resulted in the expression of chimeric in-frame fusion genes disrupting hematopoietic regulators, including ETV6-INO80D, NAP1L1-MLLT10 and RUNX1-EVX1. These results indicate that although ETP ALL is genetically heterogeneous, activation of Ras and cytokine receptor signalling distinguishes this disease from non-ETP ALL. These findings suggest that targeting this pathway may improve the currently dismal outcome of this disease.
The genetic basis of early T-cell precursor acute lymphoblastic leukaemia.
Specimen part
View SamplesEarly T-cell precursor acute lymphoblastic leukaemia (ETP ALL) is an aggressive malignancy of unknown genetic basis. We performed whole genome sequencing of tumour and normal DNA from 12 children with ETP ALL and assessed the frequency of somatic alterations in 52 ETP and 42 non-ETP T-ALL samples by sequencing and DNA copy number analysis. ETP ALL was characterised by a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling (67% of cases; NRAS, KRAS, FLT3, IL7R, JAK3, JAK1, SH2B3 and BRAF); alterations disrupting haemopoietic development (58%; GATA3, ETV6, RUNX1, IKZF1, EP300); and inactivating mutations in histone modifying genes (48%; EZH2, EED, SUZ12, SETD2 and EP300). We also identified new targets of mutation including DNM2, ECT2L and RELN. Ten of 12 ETP ALL cases harboured chromosomal rearrangements, several of which complex and resulted in the expression of novel chimeric in-frame fusion genes disrupting haemopoietic regulators. Thus, similar to myeloid malignancies, mutations that drive proliferation, impair differentiation and disrupt histone modification are hallmarks of ETP ALL. Moreover, the global transcriptional profile of ETP ALL was similar to that of normal and myeloid leukaemia haemopoietic stem cells. These findings suggest that addition of myeloid-directed therapies might improve the poor outcome of ETP ALL.
The genetic basis of early T-cell precursor acute lymphoblastic leukaemia.
Specimen part
View SamplesObjectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways.
Regulation of gene expression by PI3K in mouse growth plate chondrocytes.
No sample metadata fields
View SamplesGenome-wide mRNA expression in brains of wild-type and eIF2B-R132H/R132H mutant mice (Geva et al., BRAIN 133 (8), 2010) profiled at postnatal (P) days 1, 18 and 21 to reflect the early proliferative stage prior to white matter establishment (P1) and the peak of oligodendrocye differentiation and myelin synthesis (P18 and P21).
A point mutation in translation initiation factor eIF2B leads to function--and time-specific changes in brain gene expression.
Specimen part
View SamplesPrimary micromass cultures derived from 11.5 day old mouse embryo limb buds were cultured for 15 days in differentiating conditions (beta-glycerophosphate and ascorbic acid). Total RNA from differentiating chondrocytes was isolated every three days i.e. days 3,6,9,12 and 15 and hybridized to MOE430A chips. Objective: Gain a view of the temporal gene expression changes occuring during chondrocyte differentiation.
Microarray analyses of gene expression during chondrocyte differentiation identifies novel regulators of hypertrophy.
No sample metadata fields
View SamplesBackground: Glucocorticoids (GCs) are widely used anti-inflammatory drugs. While useful in clinical practice, patients taking GCs often suffer from skeletal side effects including growth retardation and decreased bone quality in adults. On a physiological level, GCs have been implicated in the regulation of chondrogenesis and osteoblast differentiation, as well as maintaining homeostasis in cartilage and bone. We identified the glucocorticoid receptor (GR) as a potential regulator of chondrocyte hypertrophy in a microarray screen of primary limb bud mesenchyme micromass cultures. Some targets of GC regulation in chondrogenesis are known, but the global effects of pharmacological GC doses on chondrocyte gene expression have not been comprehensively evaluated.
Expression profiling of Dexamethasone-treated primary chondrocytes identifies targets of glucocorticoid signalling in endochondral bone development.
No sample metadata fields
View SamplesA series of transfections was performed in Drosophila S2 cells to explore: 1) the types of target sites that Drosophila microRNAs recognize, 2) the relative functional efficacy of these sites in mediating repression, and 3) the determinants that allow some sites to have greater potency than others. 3p-seq was also performed to help reannotate and quantify the landscape of 3'' UTRs in Drosophila S2 cells. Overall design: Nine mRNA profiles were generated, with Drosophila S2 cells transfected with one of 6 microRNAs (miR-1, miR-4, miR-92a, miR-124, miR-263a, and miR-997). These samples were compared to 3 biological replicates of a mock transfection condition. 3p-seq data for S2 cells was also generated to help reannotate and quantify 3'' UTR isoforms.
Predicting microRNA targeting efficacy in Drosophila.
Specimen part, Subject
View SamplesA variety of cell cultures models and in vivo approaches have been used to study gene expression during chondrocyte differentiation. The extent to which the in vitro models reflect bona fide gene regulation in the growth plate has not been quantified. In addition, studies that evaluate global gene expression changes among different growth plate zones are limited. To address these issues, we completed a microarray screen of three growth plate zones derived from manually segmented embryonic mouse tibiae. Classification of genes differentially expressed between each respective growth plate zone, functional categorization as well as characterization of gene expression patterns, cytogenetic loci, signaling pathways and functional motifs confirmed documented data and pointed to novel aspects of chondrocyte differentiation. Parallel comparisons of the microdissected tibiae data set to our previously completed micromass culture screen further corroborated the suitability of micromass cultures for modeling gene expression in chondrocyte development. The micromass culture system demonstrated striking similarities to the in vivo microdissected tibiae screen; however, the micromass system was unable to accurately distinguish gene expression differences in the hypertrophic and mineralized zones of the growth plate. These studies will allow us to better understand zone-specific gene expression patterns in the growth plate. Ultimately, this work will help define both the genomic context in which genes are expressed in the long bones and the extent to which the micromass culture system is able to recapitulate chondrocyte development in endochondral ossification.
Genome-wide analyses of gene expression during mouse endochondral ossification.
No sample metadata fields
View SamplesImmunodeficient mouse models have been valuable for studies of human hematopoiesis, but high-fidelity recapitulation of erythropoiesis in most xenograft recipients remains elusive. Recently developed immunodeficient and Kit mutant mice, however, have provided a suitable background to achieve higher-level human erythropoiesis after long-term hematopoietic engraftment. While there has been some characterization of human erythropoiesis in these models, a comprehensive analysis of various developmental stages has not yet been reported. Here, we have utilized cell surface phenotypes, morphologic analyses, and molecular studies to fully characterize human erythropoiesis from multiple developmental stages in immunodeficient and Kit mutant mouse models following long-term hematopoietic stem and progenitor cell engraftment. We show that human erythropoiesis in such models demonstrates complete maturation and enucleation, as well as developmentally appropriate globin gene expression. These results provide a framework for future studies to utilize this model system for interrogating disorders affecting human erythropoiesis and for developing improved therapeutic approaches. Overall design: (mRNA-seq) RNA-seq of human CD235a+ cells isolated 14-16 weeks post-implantation from mouse bone marrow were performed for three biological replicates each of mice xenograted with adult bone marrow-derived human CD34+ cells and cord blood-derived CD34+ cells.
Developmentally-faithful and effective human erythropoiesis in immunodeficient and Kit mutant mice.
Specimen part, Subject
View Samples