Patients with medulloblastoma are typically treated with a narrow range of therapies, but may experience widely divergent outcomes; 80-90% become long-term survivors while 20% develop incurable recurrence. Transcriptomic profiling has identified four subgroups with different recurrence risks, but outcomes remain variable for individual patients within each subgroup. To gain new insight into why patients with similar-appearing tumors have variable outcomes, we examined how the timing of tumor initiation effects medulloblastomas triggered by a single, common driver mutation. We genetically-engineered mice to express an oncogenic Smo allele starting early in development in the broad lineage of neural stem cells, or later, in the more committed lineage of cerebellar granule neuron progenitors. Both groups developed medulloblastomas and no other tumors. We compared medulloblastoma progression, response to therapy, gene expression profile and cellular heterogeneity, determined by single cell transcriptomic analysis (scRNA-seq). The average transcriptomic profiles of the tumors were similar. However, stem cell-triggered medulloblastomas progressed faster, contained more OLIG2-expressing tumor stem cells, and consistently showed radioresistance. In contrast, progenitor-triggered MBs progressed slower, lost stem cell character over time and were radiosensitive. Progenitor-triggered medulloblastomas also contained more diverse stromal populations, including tumor-associated macrophages, indicating that the timing of oncogenesis affected the subsequent interactions between the tumor and microenvironment. Our findings show that developmental events in tumorigenesis may be impossible to infer from transcriptomic profile, but while remaining cryptic can nevertheless influence tumor composition and the outcome of therapy. Precise understanding of medulloblastoma pathogenesis and prognosis requires supplementing transcriptomic data with biomarkers of cellular heterogeneity.
Cryptic developmental events determine medulloblastoma radiosensitivity and cellular heterogeneity without altering transcriptomic profile.
Specimen part, Treatment
View SamplesThe formation and execution of a productive immune response requires, among many things, the maturation of competent T cells and a robust change in cellular activity upon antigen challenge. Such changes in cellular function require regulated alterations of protein expression. Much work has previously gone into defining the transcriptional changes that regulate protein expression during T cell development and antigen stimulation. Here we describe a parallel pathway of gene regulation that occurs during T cell stimulation, namely alternative splicing. Specifically, we use RNA-Seq to identify 178 exons in 168 genes that exhibit robust changes in inclusion in response to a stimulation of a human T cell line. Interestingly, these signal-responsive genes are enriched for functions related to immune response including, cell trafficking, inflammatory and immune response, immunologic disease and several cell signaling pathways. The vast majority of these genes also exhibit different isoform expression in naive and activated primary T cells. Comparison of the responsiveness of splicing to various stimuli in the cultured and primary T cells reveal important insight into the diversity of signaling pathways that control splicing. Using this data we are able to classify signal-responsive exons into at least three distinct networks. Importantly, we find that each regulatory network is characterized by distinct sequence hallmarks, further suggesting independent regulatory mechanisms. Overall design: We utilize high-throughput RNA sequencing (RNA-Seq) to investigate global changes in alternative splicing in a cultured T cell line and in primary human T cells. We identify 178 genes that are predicted to exhibit robust signal-induced changes in isoform expression in cultured T cells.
Alternative splicing networks regulated by signaling in human T cells.
Specimen part, Subject
View SamplesCellular diversity within tumors and reduced lineage commitment can undermine targeted therapy by increasing the probability of treatment-resistant populations. Using single-cell RNA-seq, we analyzed cellular diversity and lineage in medulloblastomas in transgenic, medulloblastoma-prone mice, and responses to the SHH-pathway inhibitor vismodegib. Overall design: Drop-Seq single-cell transcriptome sequencing of 15 mice: 5 Wild Type cerebella, 5 Drug-treated cerebellar tumors and 5 vehicle-treated cerebellar tumros.
scRNA-seq in medulloblastoma shows cellular heterogeneity and lineage expansion support resistance to SHH inhibitor therapy.
Specimen part, Cell line, Treatment, Subject
View SamplesDuchenne Muscular Dystrophy (DMD) is a fatal muscle wasting disorder caused by dystrophin deficiency. Previous work suggested that increased expression of the dystrophin-related protein utrophin in the mdx mouse model of DMD can prevent dystrophic pathophysiology. Physiological tests showed that the transgenic mouse muscle functioned in a way similar to normal muscle. More recently, it has become possible to analyse disease pathways using microarrays, a sensitive method to evaluate the efficacy of a therapeutic approach. We thus examined the gene expression profile of mdx mouse muscle compared to normal mouse muscle and compared the data with that obtained from the transgenic line expressing utrophin. The data confirm that the expression of utrophin in the mdx mouse muscle results in a gene expression profile virtually identical to that seen for the normal mouse. This study confirms that a strategy to up-regulate utrophin is likely to be effective in preventing the disease.
Microarray analysis of mdx mice expressing high levels of utrophin: therapeutic implications for dystrophin deficiency.
No sample metadata fields
View SamplesThere is much evidence that T cells may be activated via mechanisms which act independently of direct TCR ligation. Despite this, the question of whether such forms of bystander T cell activation occur during immune responses is hotly debated.
Human CD4+ memory T cells are preferential targets for bystander activation and apoptosis.
No sample metadata fields
View SamplesReplicating viruses have broad applications in biomedicine, notably in cancer virotherapy and in the design of attenuated vaccines, however uncontrolled virus replication in vulnerable tissues can give pathology and often restricts the use of potent strains. Increased knowledge of tissue-selective microRNA expression now affords the possibility of engineering replicating viruses that are attenuated at the RNA level in sites of potential pathology, but retain wild type replication activity at sites not expressing the relevant microRNA.
MicroRNA controlled adenovirus mediates anti-cancer efficacy without affecting endogenous microRNA activity.
Sex, Age, Specimen part, Treatment
View SamplesOligodendrocyte precursor cells from postnatal day 10 optic nerve remained in a developmentally immature state in LIF-/- mice. Partial recovery of myelin genes is seen in LIF-/- mice by postnatal day 14 in the optic nerve. Very little difference in myelin genes in the optic nerve is seen by postnatal day 35 (adult).
Leukemia inhibitory factor regulates the timing of oligodendrocyte development and myelination in the postnatal optic nerve.
Sex, Specimen part
View SamplesThe mammalian suprachiasmatic nucleus (SCN) drives daily rhythmic behavior and physiology, yet a detailed understanding of its coordinated transcriptional programmes is lacking. To reveal the true nature of circadian variation in the mammalian SCN transcriptome we combined laser-capture microdissection (LCM) and RNA-Seq over a 24-hour light / dark cycle. We show that 7-times more genes exhibited a classic sinusoidal expression signature than previously observed in the SCN. Another group of 766 genes unexpectedly peaked twice, near both the start and end of the dark phase; this twin-peaking group is significantly enriched for synaptic transmission genes that are crucial for light-induced phase-shifting of the circadian clock. 342 intergenic non-coding RNAs, together with novel exons of annotated protein-coding genes, including Cry1, also show specific circadian expression variation. Overall, our data provide an important chronobiological resource (www.wgpembroke.com/shiny/SCNseq/) and allow us to propose that transcriptional timing in the SCN is gating clock resetting mechanisms. Overall design: Pooled dissected tissue of the suprachiasmatic nucleus from five adult male mice provided one of three replicates for each of six timepoints over a 12:12 light/dark (LD) cycle (ZT2, 6, 10, 14, 18 and 22). Each biological replicate was sequenced over 3 seperate lanes using Illumina HiSeq.
Temporal transcriptomics suggest that twin-peaking genes reset the clock.
Specimen part, Cell line, Subject
View SamplesIn the normal mouse the pituitary gonadotrophins determine development, maturation and physiological regulation of the testis with follicle-stimulating hormone (FSH) activating the Sertoli cell and luteinising hormone (LH) the Leydig cell. To look at the potential interaction of cell types within the testis following hormone stimulation we have investigated the effect of rFSH on testicular gene expression in the hypogonadal (hpg) male mouse. Due to a deletion in the gene encoding gonadotrophin-releasing hormone (GnRH), FSH and LH levels are at the lower limit of detection in the circulation and mice remain in a pre-pubertal state throughout life unless given exogenous hormone.
Effects of FSH on testicular mRNA transcript levels in the hypogonadal mouse.
No sample metadata fields
View SamplesLow incubation temperature during early development negatively affects survival and related innate immune processes in zebrafish larvae exposed to lipopolysaccharide Overall design: Zebrafish embryos were collected from 28 °C, and divided into three temperature groups (24 °C, 28 °C, 32 °C) for incubation. At the first-feeding stage, larvae from each incubation temperature group were further split into three temperature groups in a full-factorial way for LPS challenge. In total, nine temperature groups (three incubation temperatures x three challenge temperatures) were generated. At 24 h post LPS challenge, mortality of larvae were recorded. Larvae originating from 24 °C incubation temperature group had higher mortality rate than larvae from the other two temperature groups. LPS-treated larvae from three temperature groups, incubation 24 °C x challenge 24 °C, incubation 24 °C x challenge 32 °C, and incubation 32 °C x challenge 24 °C, together with their respective control were chosen for transcriptomic analyses using mRNA sequencing. A total of 722 genes were determined differentially expressed (DEGs) by DESeq2 (adjusted p-value < 0.05) in LPS-challenged larvae compared to control, and 605 of them had a fold change greater than 1.5, including 294 DEGs (144 up-/150 down-regulated) in larvae incubated and challenged with LPS at 24 °C; 33 DEGs (20 up-/13 down-regulated) in larvae incubated at 32 °C and challenged at 24 °C; and 278 DEGs (190 up-/88 down-regulated) in larvae incubated at 24 °C and challenged at 32 °C. Larvae incubated and challenged with LPS at 24 °C had stimulated innate immune response compared to control, while they also showed down-regulated innate immune processes and genes. In larvae incubated at 32 °C and challenged at 24 °C, the innate immune processes were up-regulated in larvae exposed to LPS compared to control, and theses processes were even much stronger (with higher enrichment values) than larvae from incubation and challenge temperature of 24 °C. In larvae incubated at 24 °C and challenged with LPS at 32 °C, limited innate immune response were up-regulated, and additional hypoxia and oxidative processes were observed. Genes annexin A2a, S100 calcium binding protein A10b, and lymphocyte antigen-6, epidermis were identified as promising candidates for LPS recognition and signal transduction.
Low incubation temperature during early development negatively affects survival and related innate immune processes in zebrafish larvae exposed to lipopolysaccharide.
Specimen part, Cell line, Subject
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