Background: The vast majority of human genes (.70%) are alternatively spliced. Although alternative pre-mRNA processing is modified in multiple tumors, alternative hyper-splicing signatures specific to particular tumor types are still lacking. Here, we report the use of Affymetrix Human Exon Arrays to spot hyper-splicing events characteristic of myasthenia gravis (MG)-thymoma, thymic tumors which develop in patients with MG and discriminate them from colon cancer changes. Methodology/Principal Findings: We combined GO term to parent threshold-based and threshold-independent ad-hoc functional statistics with in-depth analysis of key modified transcripts to highlight various exon-specific changes. These denote alternative splicing in MG-thymoma tumors compared to healthy human thymus and to in-house and Affymetrix datasets from colon cancer and healthy tissues. By using both global and specific, term-to-parent Gene Ontology (GO) statistical comparisons, our functional integrative ad-hoc method allowed the detection of disease-relevant splicing events. Conclusions/Significance: Hyper-spliced transcripts spanned several categories, including the tumorogenic ERBB4 tyrosine kinase receptor and the connective tissue growth factor CTGF, as well as the immune function-related histocompatability gene HLA-DRB1 and interleukin (IL)19, two muscle-specific collagens and one myosin heavy chain gene; intriguingly, a putative new exon was discovered in the MG-involved acetylcholinesterase ACHE gene. Corresponding changes in spliceosome composition were indicated by co-decreases in the splicing factors ASF/SF2 and SC35. Parallel tumor-associated changes occurred in colon cancer as well, but the majority of the apparent hyper-splicing events were particular to MGthymoma and could be validated by Fluorescent In-Situ Hybridization (FISH), Reverse TranscriptionPolymerase Chain Reaction (RT-PCR) and mass spectrometry (MS) followed by peptide sequencing. Our findings demonstrate a particular alternative hyper-splicing signature for transcripts over-expressed in MG-thymoma, supporting the hypothesis that alternative hyper-splicing contributes to shaping the biological functions of these and other specialized tumors and opening new venues for the development of diagnosis and treatment approaches
Identifying alternative hyper-splicing signatures in MG-thymoma by exon arrays.
Sex
View SamplesSeveral studies indicate that adult stem cells may improve the recovery from acute tissue injury. It has been suggested that they may contribute to tissue regeneration by the release of paracrine factors promoting proliferation of tissue resident cells. However, the factors involved remain unknown. In the present study we found that microvesicles (MV) derived from human liver stem cells (HLSC) were able to stimulate in vitro proliferation and apoptosis resistance of human and rat hepatocytes. These effects required internalization of MV in the hepatocytes by an alpha4 integrin-dependent mechanism. However, when treated with RNase, MV despites their internalization were unable to induce hepatocyte proliferation and apoptosis resistance, suggesting an RNA dependent effect. Microarray analysis and quantitative RT-PCR demonstrated that MV were shuttling a specific subset of cellular mRNA, such as mRNA associated in the control of transcription, translation, proliferation and apoptosis. When administered in vivo, MV were found to accelerate the morphological and functional recovery of liver in a model of 70% hepatectomy in rats by inducing an hepatocytes proliferation that was abolished by RNase treatment. Using human AGO2 gene, which is shuttled by MV, as a reporter gene, we found the expression of human AGO2 mRNA and protein in the liver of hepatectomized rats treated with MV. This suggest a translation of the MV shuttled mRNA within hepatocytes of treated rats. Conclusion: these results suggest that MV derived from HLSC may activate a proliferative program in remnant hepatocytes after hepatectomy by a horizontal transfer of specific mRNA subsets.
Human liver stem cell-derived microvesicles accelerate hepatic regeneration in hepatectomized rats.
Specimen part
View SamplesPD is the second most common neurodegenerative disease worldwide with growing prevalence. MPTP is a neurotoxin which causes the appearance of Parkinson's disease (PD) pathology. The involvement of the cholinergic system in PD has been identified decades ago and anti-cholinergic drugs were upon the first drugs used for symptomatic treatment of PD. Of note, MPTP intoxication is a model of choice for symptomatic neuroprotective therapies since it have been quite predictive. Mice were exposed to the dopaminergic neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP), with or without the protective acetylcholinesterase (AChE-R) variant. Transgenic AChE-S (the synaptic variant), AChE-R (the shorter, protective variant) and FVB/N control mice were included in this study. Two brain regions were examined: the pre-frontal cortex (PFC) and the striatal caudate-putamen (CPu). Each condition (i.e brain region and transgenic variant) was examined on both naive and MPTP-exposed mice.
Meta-analysis of genetic and environmental Parkinson's disease models reveals a common role of mitochondrial protection pathways.
Specimen part, Treatment
View SamplesSub-thalamic deep brain stimulation (DBS) reversibly modulates Parkinsons disease (PD) motor symptoms, providing an unusual opportunity to compare leukocyte transcripts in the same subjects before and after neurosurgery and after disconnecting the stimulus (ON-and OFF-stimulus). Here, we report rapid stimulus-induced and largely reversible changes in PD leukocyte transcripts, which were larger in scope than the disease-induced changes. These transcript changes classified advanced pre- from post-surgery PD patients and discriminated patients from controls. Moreover, the extent of changes correlated with the neurological efficacy of the DBS neurosurgery, and covered both regulatory pathways and individual transcript changes, e.g. SNCA, PARK7 and the splicing factor SFRS1. Following 1 hour OFF-stimulus, these changes were largely reversed. We extracted from these differences a modified transcripts signature which discriminated controls from advanced PD patients, pre- from post-surgery and ON-from OFF-stimulus conditions. A further gene-list independent analysis detected reversed pathways. Our findings suggest future uses of this approach and the discovered molecular signature for early diagnostics of PD and for identifying novel targets for therapeutic intervention in this and other DBS-treatable neurological diseases.
Deep brain stimulation induces rapidly reversible transcript changes in Parkinson's leucocytes.
Sex, Specimen part, Disease stage
View SamplesRNAseq data for Col-0. cob-6, sfr6-3 and cob-6sfr6-3 Overall design: 7 days old seedlings grown in 24h light with 0
Identification of MEDIATOR16 as the Arabidopsis COBRA suppressor MONGOOSE1.
Specimen part, Subject
View Samplesthree replicates of HT29 cells per conditionwere grown under normoxic and hypoxic conditions. RNA and miRNA was extracted from each replicate and run on the GPL570 and GPL5106 arrays respectively.
Role of oxygen availability in CFTR expression and function.
No sample metadata fields
View SamplesYB-1 controls epithelial-mesenchymal transitions by restricting translation of growth-related mRNAs and enabling expression of EMT-inducing transcription factors. We used microarrays to characterize the direct transcriptional and indirect translational regulation of mRNAs by exogenous YB-1 in breast cancer cell lines.
Translational activation of snail1 and other developmentally regulated transcription factors by YB-1 promotes an epithelial-mesenchymal transition.
No sample metadata fields
View SamplesThe level of trypsin-2 has been shown to correlate with the malignancy and metastatic potential of many cancer.
Trypsin-2 enhances carcinoma invasion by processing tight junctions and activating ProMT1-MMP.
Specimen part, Cell line
View SamplesNovel prognostic subclasses of high-grade astrocytoma are identified and discovered to resemble stages in neurogenesis. One tumor class displaying neuronal lineage markers shows longer survival, while two tumor classes enriched for neural stem cell markers display equally short survival. Poor prognosis subclasses exhibit either markers of proliferation or of angiogenesis and mesenchyme. Analysis of gene expression data is described in Phillips et al., Cancer Cell, 2006.
Molecular subclasses of high-grade glioma predict prognosis, delineate a pattern of disease progression, and resemble stages in neurogenesis.
Sex, Age, Disease stage
View SamplesHalf of all human cancers lose p53 function by missense mutations, with an unknown fraction of these containing p53 in a self-aggregated, amyloid-like state. Here we show that a cell-penetrating peptide, ReACp53, designed to inhibit p53 amyloid formation, rescues p53 function in cancer cell lines and in organoids derived from high-grade serous ovarian carcinomas (HGSOC), an aggressive cancer characterized by ubiquitous p53 mutations. Rescued p53 behaves similarly to its wild-type counterpart in regulating target genes, reducing cell proliferation and increasing cell death. Intraperitoneal administration decreases tumor proliferation and shrinks xenografts in vivo. Our data show the effectiveness of targeting a specific aggregation defect of p53 and its potential applicability to HGSOCs. Overall design: Vehicle vs. ReACp53 treatment in 4 different samples: 2 cell lines (MCF7 w/ WT p53 as negative control and OVCAR3 w/ R248Q p53) and 2 clinical specimens (primary cells from patient #8 w/ WT p53 as negative control and primary cells from patient #1 w/ R248Q p53)
A Designed Inhibitor of p53 Aggregation Rescues p53 Tumor Suppression in Ovarian Carcinomas.
No sample metadata fields
View Samples