The tissue of origin form metastatic tumors is sometimes difficult to identify from clinical and histologic information. Gene expression signatures are one potential method for identifying the tissue of origin. In the development of algorithms to identify tissue of origin, a collection of human tumor metastatic specimens with known primary sites or primary tumors with poor differentiation are very useful in identifying gene expressions signatures that can classify unknown specimens as to the tissue of origin. Here we describe a series of 276 such tumor specimens used for this purpose. The specimens are poorly differentiated, undifferentiated and metastatic specimens from tumors of the following types/tissues of origin: breast, liver, non-Hodgkin's lymphoma, non-small cell lung cancer, ovary, testicular germ cell, thyroid, kidney, pancreas, colorectal cancer, soft tissue sarcoma, bladder, gastric cancer, prostate and melanoma. This data combined with other series (GSE2109) was used to validate a proprietary tumor classification algorithm of Pathwork Diagnostics. The results of this validation set (N = 545 CEL files) showed that the algorithm correctly identified the tissue of origin for 89.4% of the specimens.
Multicenter validation of a 1,550-gene expression profile for identification of tumor tissue of origin.
Sex, Age
View SamplesMicroRNAs (miRNAs) post-transcriptionally regulate the expression of thousands of distinct mRNAs. While some regulatory interactions help to maintain basal cellular functions, others are likely relevant in more specific settings, such as response to stress. Here we describe such a role for the mir-290-295 cluster, the dominant miRNA cluster in mouse embryonic stem cells (mESCs). Examination of a target list generated from bioinformatic prediction, as well as expression data following miRNA loss, revealed strong enrichment for apoptotic regulators, two of which we validated directly: Caspase 2, the most highly conserved mammalian caspase, and Ei24, a p53 transcriptional target. Consistent with these predictions, mESCs lacking miRNAs were more likely to initiate apoptosis following genotoxic exposure to gamma irradiation or doxorubicin. Knockdown of either candidate partially rescued this pro-apoptotic phenotype, as did transfection of members of the mir-290-295 cluster. These findings were recapitulated in a specific mir-290-295 deletion line, confirming that they reflect miRNA functions at physiological levels. In contrast to the basal regulatory roles previously identified, the pro-survival phenotype shown here may be most relevant to stressful gestations, where pro-oxidant metabolic states induce DNA damage. Similarly, this cluster may mediate chemotherapeutic resistance in a neoplastic context, making it a useful clinical target.
A latent pro-survival function for the mir-290-295 cluster in mouse embryonic stem cells.
Specimen part
View SamplesWe sequenced strand-specific mRNA from the heads of 3 groups of wild type zebrafish (Danio rerio) 5 days post fertilization. Overall design: Examination of the relative expression of genes in the developing zebrafish brain
BRF1 mutations alter RNA polymerase III-dependent transcription and cause neurodevelopmental anomalies.
No sample metadata fields
View SamplesLMP2A of Epstein-Barr virus is a receptor that mimics an activated B cell receptor, BCR. K1 and K15, related receptors of Kaposi sarcoma-associated herpes virus, KSHV, are expressed in virus-associated tumors but their functions are less obvious. We addressed this uncertainty with mutant EBVs encoding the KSHV genes K1 or K15 in lieu of LMP2A and infected primary human B cells with them. K1 and K15 encoded proteins appear to have noncomplementing redundant functions in this model but our findings suggest that both KSHV proteins can replace LMP2As key activities contributing to the survival, activation and proliferation of B cells.
K1 and K15 of Kaposi's Sarcoma-Associated Herpesvirus Are Partial Functional Homologues of Latent Membrane Protein 2A of Epstein-Barr Virus.
Specimen part, Subject
View SamplesCellular senescence is a program of irreversible cell cycle arrest that normal cells undergo in response to progressive shortening of telomeres, changes in telomeric structure, oncogene activation or oxidative stress. The underlying signalling pathways, potentially of major clinicopathological relevance, are unknown. A major stumbling block to studying senescence has been the absence of suitable model systems because of the asynchrony of this process in heterogeneous cell populations. To simplify this process many investigators study oncogene-induced senescence due to expression of activated oncogenes where senescence occurs prematurely without telomere attrition and can be induced acutely in a variety of cell types. We have taken a different approach by making use of the finding that reconstitution of telomerase activity by introduction of the catalytic subunit of human telomerase alone is incapable of immortalising all human somatic cells, but inactivation of the p16-pRB and p53-p21 pathways are required in addition. The ability of SV40 large T antigen to inactivate the p16-pRB and p53-p21 pathways has enabled us to use a thermolabile mutant of LT antigen, in conjunction with hTERT, to develop conditionally immortalised human (HMF3A) fibroblasts that are immortal but undergo an irreversible growth arrest when the thermolabile LT antigen is inactivated leading to activation of pRB and p53. When these cells cease dividing, senescence-associated- b-galactosidase activity is induced and the growth-arrested cells have morphological features and express genes in common with senescent cells. Since these cells growth arrest in a synchronous manner they are an excellent starting point for dissecting the pathways that underlie cellular senescence and act downstream of p16-pRB and p53-p21 pathways. We have combined genome-wide expression profiling with genetic complementation to undertake identification of genes that are differentially expressed when these conditionally immortalised human fibroblasts undergo senescence upon activation of the p16-pRB and p53-p21 tumour suppressor pathways.
Activation of nuclear factor-kappa B signalling promotes cellular senescence.
Cell line, Treatment
View SamplesPseudomonas fluorescens strain SS101 (Pf.SS101) promotes growth of Arabidopsis thaliana, enhances greening and lateral root formation, and induces systemic resistance (ISR) against the bacterial pathogen Pseudomonas syringae pv. tomato (Pst). Here, targeted and untargeted approaches were adopted to identify bacterial determinants and underlying mechanisms involved in plant growth promotion and ISR by Pf.SS101. Based on targeted analyses, no evidence was found for volatiles, lipopeptides and siderophores in plant growth promotion by Pf.SS101. Untargeted, genome-wide analyses of 7,488 random transposon mutants of Pf.SS101 led to the identification of 21 mutants defective in both plant growth promotion and ISR. Many of these mutants, however, were auxotrophic and impaired in root colonization. Genetic analysis of three mutants followed by site-directed mutagenesis, genetic complementation and plant bioassays revealed the involvement of the phosphogluconate dehydratase gene edd, the response regulator gene colR and the adenylsulfate reductase gene cysH in both plant growth promotion and ISR. Subsequent comparative plant transcriptomics analyses strongly suggest that modulation of sulfur assimilation, auxin biosynthesis and transport, steroid biosynthesis and carbohydrate metabolism in Arabidopsis are key mechanisms linked to growth promotion and ISR by Pf.SS101.
Genome-wide analysis of bacterial determinants of plant growth promotion and induced systemic resistance by Pseudomonas fluorescens.
Specimen part, Treatment
View SamplesGene expression of mouse hepatic stellate cells was characterized under the following conditions:
Deactivation of hepatic stellate cells during liver fibrosis resolution in mice.
Sex, Specimen part
View SamplesPrecise 5' splice site recognition is essential for both constitutive and regulated pre-mRNA splicing. The U1 snRNP specific protein U1C is involved in this first step of spliceosome assembly and important for stabilizing early splicing complexes. We used an embryonically lethal U1C knockout mutant zebrafish, hi1371, to investigate the potential genomewide role of U1C for splicing regulation. Surprisingly, genomewide RNA-Seq analysis of mutant versus wildtype embryos revealed a large set of specific target genes that changed their alternative splicing patterns in the absence of U1C. In sum, our findings provide evidence for a new role of a general snRNP protein, U1C, as a mediator of alternative splicing regulation.
RNA-Seq analysis in mutant zebrafish reveals role of U1C protein in alternative splicing regulation.
No sample metadata fields
View SamplesPurpose: Severe late normal tissue damage limits radiotherapy treatment regimens. This study aims to validate -H2AX foci decay ratios and induced expression levels of DNA double strand break (DSB) repair genes, found in a retrospective study, as possible predictors for late radiation toxicity. Methods and Materials: Prospectively, decay ratios (initial/residual -H2AX foci numbers) and genome-wide expression profiles were examined in ex vivo irradiated lymphocytes of 198 prostate cancer patients. All patients were followed 2 years after radiotherapy, clinical characteristics were assembled and toxicity was recorded using the Common Terminology Criteria (CTCAE) v4.0. Results: No clinical factors were correlated with late radiation toxicity. Analysis of -H2AX foci uncovered a negative correlation between the foci decay ratio and toxicity grade. Significantly smaller decay ratios were found in grade3 compared to grade 0 patients (p=0.02), indicating less efficient DNA-DSB repair in radio-sensitive patients. Moreover, utilizing a foci decay ratio threshold determined in our previous retrospective study correctly classified 23 of the 28 grade3 patients (sensitivity, 82%) and 9 of the 14 grade 0 patients (specificity, 64%). Grade of toxicity also correlated with a reduced induction of the homologous recombination (HR) repair gene-set. The difference in average fold induction of the HR gene-set was most pronounced between grade 0 and grade3 patients (p=0.008). Conclusions: Reduced responsiveness of HR repair genes to irradiation and inefficient DSB repair correlate with an increased risk of late radiation toxicity. Using a decay ratio classifier, we could correctly classify 82% of the patients with grade3 toxicity. Additional studies are required to further optimize and validate the foci decay assay and to assess its predictive value for late radiation toxicity in patients prostate cancer
Prostate Cancer Patients with Late Radiation Toxicity Exhibit Reduced Expression of Genes Involved in DNA Double-Strand Break Repair and Homologous Recombination.
Specimen part, Subject
View SamplesConsidering the numerous complex and different pathological mechanisms involved in Alzheimers disease (AD) progression, treatments targeting a single cause may lead to limited benefits. The goal of this study was the identification of a novel mode of action for this unmet need. Pharmacological tool compounds: suberoylanilide hydroxamic acid (SAHA) and tadalafil, targeting histone deacetylases (HDAC) and phosphodiesterase 5 (PDE5) respectively, were utilized simultaneously for in-vitro and in-vivo Proof-of-Concept (PoC). A synergistic effect was observed in the amelioration of AD signs using the combination therapy in Tg2576 mice. Finally, a therapeutic agent, CM-414, inhibiting simultaneously HDAC2/6 and PDE5 was generated and tested in Tg2576 mice. CM-414 reversed cognitive impairment, reduced amyloid and tau pathology, and rescued dendritic spine density loss in the hippocampus in AD mice. Importantly, the effect obtained was present after a 4-weeks wash-out period.
Concomitant histone deacetylase and phosphodiesterase 5 inhibition synergistically prevents the disruption in synaptic plasticity and it reverses cognitive impairment in a mouse model of Alzheimer's disease.
Specimen part
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