Not all patients with nerve injury develop neuropathic pain. The extent of nerve damage and age at the time of injury are two of the few risk factors identified to date. In addition, preclinical studies show that neuropathic pain variance is heritable. To define such factors further, we performed a large-scale gene profiling experiment which plotted global expression changes in the rat dorsal root ganglion in three peripheral neuropathic pain models. This resulted in the discovery that the potassium channel alpha subunit KCNS1, involved in neuronal excitability, is constitutively expressed in sensory neurons and markedly downregulated following nerve injury. KCNS1 was then characterized by an unbiased network analysis as a putative pain gene, a result confirmed by single nucleotide polymorphism association studies in humans. A common amino acid changing allele, the 'valine risk allele', was significantly associated with higher pain scores in five of six independent patient cohorts assayed (total of 1359 subjects). Risk allele prevalence is high, with 18-22% of the population homozygous, and an additional 50% heterozygous. At lower levels of nerve damage (lumbar back pain with disc herniation) association with greater pain outcome in homozygote patients is P = 0.003, increasing to P = 0.0001 for higher levels of nerve injury (limb amputation). The combined P-value for pain association in all six cohorts tested is 1.14 E-08. The risk profile of this marker is additive: two copies confer the most, one intermediate and none the least risk. Relative degrees of enhanced risk vary between cohorts, but for patients with lumbar back pain, they range between 2- and 3-fold. Although work still remains to define the potential role of this protein in the pathogenic process, here we present the KCNS1 allele rs734784 as one of the first prognostic indicators of chronic pain risk. Screening for this allele could help define those individuals prone to a transition to persistent pain, and thus requiring therapeutic strategies or lifestyle changes that minimize nerve injury.
Multiple chronic pain states are associated with a common amino acid-changing allele in KCNS1.
Age
View SamplesSustained Ca2+ entry into CD4+CD8+ double-positive thymocytes is required for positive selection. We identified a voltage-gated Na+ channel (VGSC), essential for positive selection of CD4+ T cells. Pharmacological inhibition of VGSC activity inhibited sustained Ca2+ influx induced by positive-selecting ligands and in vitro positive selection of CD4+ but not CD8+ T cells. In vivo shRNA knockdown of Scn5a specifically inhibited positive selection of CD4+ T cells. Ectopic expression of VGSC in peripheral AND CD4+ T cells bestowed the ability to respond to a positively selecting ligand, directly demonstrating VGSC expression was responsible for increased sensitivity. Thus active VGSCs in thymocytes provides a mechanism by which a weak positive selecting signal can induce sustained Ca2+ signals required for CD4+ T cell development.
A voltage-gated sodium channel is essential for the positive selection of CD4(+) T cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
ELF5 suppresses estrogen sensitivity and underpins the acquisition of antiestrogen resistance in luminal breast cancer.
Cell line, Treatment, Time
View SamplesMutations affecting the RAS-MAPK pathway frequently occur in relapse neuroblastoma tumors, which suggests that activation of this pathway is associated with a more aggressive phenotype. To explore this hypothesis we generated several model systems to define a neuroblastoma RAS-MAPK pathway signature. We could show that activation of this pathway in primary tumors indeed correlates with poor survival and is associated with known activating mutations in ALK and other RAS-MAPK pathway genes. From integrative analysis we could show that mutations in PHOX2B, CIC and DMD are also associated with an activated RAS-MAPK pathway. Mutation of PHOX2B and deletion of CIC in neuroblastoma cell lines induces activation of the RAS-MAPK pathway. This activation was independent of phosphorylated ERK in the CIC knock out systems. Furthermore, deletion of CIC causes a significant increase in tumor growth in vivo. These results show that the RAS-MAPK pathway is involved in tumor progression, and establish CIC as a powerful tumor suppressor that functions downstream of this pathway in neuroblastoma.
RAS-MAPK Pathway-Driven Tumor Progression Is Associated with Loss of CIC and Other Genomic Aberrations in Neuroblastoma.
Cell line
View SamplesIn order to determine BCL6 target genes an EBV negative Burkitt's lymphoma cell line, DG75, was stably transfected with a tetracycline transactivator and tight doxycycline responsive expression of GFP was established. The endogenous BCL6 genes of this cell line were disrupted by homologous recombination and a BCL6 cDNA downstream of tetracycline responsive elements (TRE) was inserted to produce Bcl6-/-:tetBCL6-HA cells. Westerns demonstrated doxycycline dependent BCL6 expression.Bcl6-/-:tet. BCL6-HA cells (clone AB7) were either grown without doxycycline (control) or with 1 ug/ml doxycycline for 16, 48 or 96 hours. Total RNA was extracted using RNeasy minipreps (Qiagen) and concentration and quality were checked on the NanoDrop ND- 1000 spectrophotometer (NanoDrop Technologies, USA) and the RNA Nano 6000 kit (Agilent Technologies) on a 2100 Bioanalyzer (Agilent Technologies). One hundred ng of total RNA was processed with the GeneChip Eukaryotic Whole Transcript Sense Target Labelling Assay kit (Affymetrix) according to the manufacturer's details. Hybridisation and scanning of GeneChips was carried out at the CSC/IC Microarray Centre, MRC Clinical Sciences Centre Imperial College London and data analysis by Bioinformatics Support Service, Imperial College London. Briefly, pre- processing of data was performed using GeneSpring GX 10.0.2 software (Agilent Technologies) which applied the "Exon RMA16" algorhithm to the data set. Exon RMA16 performs background correction, quantile normalisation, median polish summarisation and variance stabilisation of 16. In background correction, intensity values of each individual array are corrected for non-specific binding by subtracting the average signal intensity of the area between spots from each probe set. Normalisation is required so multiple chips can be compared to each other. Quantile normalisation adjusts the distribution of probe intensity of each array analysed and so that the distribution of probe intensities for each array in a set of arrays is the same. Probe summarisation refers to the conversion of probe level values (there are approximately 26 probes per gene on each GeneChip) to a single probe set expression value. Variance stabilisation of 16 refers to the addition of the value 16 to the expression values. By increasing the expression value, the variance of the data set is reduced and the distribution (defined by its mean and its variance) is stabilised.
Synthetic Lethal Screen Demonstrates That a JAK2 Inhibitor Suppresses a BCL6-dependent IL10RA/JAK2/STAT3 Pathway in High Grade B-cell Lymphoma.
Cell line
View SamplesInflorescence stages 1 to 12 from mutants involved in Arabidopsis small RNA metabolism. Three biological replicates of each mutant comprising at least 9 independent plants were harvested, and the expression profiles were determined using Affymetrix ATH1 arrays. Comparisons among the sample groups allow the identification of genes regulated by small RNAs (microRNAs and siRNAs).
microRNA-directed phasing during trans-acting siRNA biogenesis in plants.
No sample metadata fields
View SamplesT helper cell subsets have unique calcium (Ca2+) signals when activated with identical stimuli. The regulation of these Ca2+ signals and their correlation to the biological function of each T cell subset remains unclear. Trpm4 is a Ca2+-activated cation channel that we found is expressed at higher levels in Th2 cells compared to Th1 cells. Inhibition of Trpm4 expression increased Ca2+ influx and oscillatory levels in Th2 cells and decreased influx and oscillations in Th1 cells. This inhibition of Trpm4 expression also significantly altered T cell cytokine production and motility. Our experiments revealed that decreasing Trpm4 levels divergently regulates nuclear localization of NFAT. Consistent with this, gene profiling did not show Trpm4 dependent transcriptional regulation and T-bet and GATA-3 levels remain identical. Thus, Trpm4 is expressed at different levels on T helper cells and plays a distinctive role in T cell function by differentially regulating Ca2+ signaling and NFAT localization.
Trpm4 differentially regulates Th1 and Th2 function by altering calcium signaling and NFAT localization.
Specimen part, Treatment, Time
View SamplesThe primary aim of this study was to evaluate the changes in hepatocyte gene expression under short-term hypoxic conditions in wild type and HIF-1a null cultures. To this end, hypoxia treated cultures were subjected to incubation with 1% O2/5% CO2/94% N2 at 37 C for eight hours prior to RNA isolation. Duplicate normoxic controls were established from separate animals wherein cultures were untreated and treated with Adbgal. Biological triplicates of wild type and HIF-1a null cultures were placed under hypoxic conditions and subsequently processed for microarray analysis. A total of 10 microarray hybridizations were performed.
In vitro liver tissue model established from transgenic mice: role of HIF-1alpha on hypoxic gene expression.
No sample metadata fields
View SamplesEstrogen-responsive genes were identified by transcript profiling of estrogen-treated MCF-7 breast cancer cells.
Identification of functional networks of estrogen- and c-Myc-responsive genes and their relationship to response to tamoxifen therapy in breast cancer.
No sample metadata fields
View SamplesProlactin and progesterone act together to regulate mammary alveolar development, and both hormones have been implicated in breast cancer initiation and progression. Here we show that Elf5, a prolactin-induced ETS transcription factor that specifies the mammary secretory cell lineage, is also induced by progestins in breast cancer cells via a direct mechanism. To define the transcriptional response to progestin elicited via Elf5 we made an inducible Elf5 sh-RNA knock down model in T47D breast cancer cells and used it to prevent the progestin-induction of Elf5. Functional analysis of Affymetrix gene expression data using Gene Ontologies and Gene Set Enrichment Analysis showed enhancement of the progestin effects on cell cycle gene expression. Cell proliferation assays showed a more efficacious progestin-induced growth arrest when Elf5 was kept at baseline levels. These results showed that progestin-induction of Elf5 expression tempered the anti-proliferative effects of progestins in T47D cells, providing a further mechanistic link between prolactin and progestin in the regulation of mammary cell phenotype.
The antiproliferative effects of progestins in T47D breast cancer cells are tempered by progestin induction of the ETS transcription factor Elf5.
Disease, Cell line, Treatment
View Samples