Efficient identification of microRNAs for classification of tumor origin (II)
ABSTRACT: Carcinomas of unknown primary origin constitute 3-5% of all newly diagnosed metastatic cancers, of which the primary source is difficult to classify with current histological methods. Effective cancer treatment depends on early and accurate identification 220 samples
Project description:Carcinomas of unknown primary origin constitute 3-5% of all newly diagnosed metastatic cancers, of which the primary source is difficult to classify with current histological methods. Effective cancer treatment depends on early and accurate identification of the tumor, which is why patients with metastases of unknown origin have poor prognosis and short survival. Because microRNA expression is highly tissue specific, the microRNA profile of a metastasis may be used to identify its origin. As a first step to realize this goal, we evaluated the potential of microRNA profiling for identification of the primary tumor of known metastases. 208 formalin-fixed paraffin-embedded samples representing 15 different histologies were profiled on an LNA-enhanced microarray platform, which allows for highly sensitive and specific detection of microRNA. Based on these data, we developed and cross-validated a novel classification algorithm, LASSO (Least Absolute Shrinkage and Selection Operator), which had an overall accuracy of 85%. When the classifier was applied on an independent test set of 48 metastases, the primary site was correctly identified in 42 cases (88% accuracy). Our findings suggest that microRNA expression profiling on paraffin tissue can efficiently predict the primary origin of a tumor, and may provide pathologists with a molecular diagnostic tool that can improve their capability to correctly identify the origin of hitherto unidentifiable metastatic tumors, and eventually, enable tailored therapy. 94 samples
Project description:Focal ischemia is triggered by the sudden significant reduction of blood supply to the brain, as a result of either the rupture or occlusion by thrombus/embolism of a blood vessel in the brain. Permanent focal ischemia occurred when blood supply to a specific part of the brain is impeded without reperfusion. Despite major steps achieved in the elucidation of the patho-physiology of cerebral ischemia, the available therapeutic avenues for acute ischemic stroke remain scarce. Cell cycle re-activation has been revealed as a novel signaling pathway during permanent focal ischemia. As such, non-specific aurora kinase inhibitor ZM447439, has been injected intracranial-ventricularly 30min post-ischemia induction to determine its efficacy in reduction of neuronal damage in terms of infarct volume. miRNA microarray analysis was performed on Exiqon 5th generation - hsa, mmu & rno (Product no: 208300-A) to compliment our existing gene expression microarray data [GSE23651]. Arrays were run as dual colour (Hy3: Sample, and Hy5: Common sample reference pool). Right cortex RNA samples were collected at two time-points (8h and 24h )respectively for all three experimental conditions: Sham (n=4), vehicle (i.e. ischemic injury with i.c.v. injection 80% DMSO; n=4) and treatment (injury plus i.c.v.injection of 30mM ZM447439 in 80% DMSO; n=4). Supplementary file: Project_Summary_Report.txt The percentages listed in the top row are present-call rates, i.e. number of identified miRNAs compared to number of miRNAs on array.
Project description:Upon muscle injury the high mobility group box 1 (HMGB1) protein is up-regulated and secreted to initiate reparative responses. Here we show that HMGB1 controls myogenesis both in vitro and in vivo, during development and after adult muscle injury. HMGB1 expression in muscle cells is regulated at the translational level: the miRNA miR-1192 inhibits HMGB1 translation and the RNA-binding protein HuR promotes it. HuR binds to a cis-element, HuRBS, located in the 3'UTR of the HMGB1 transcript, and at the same time miR-1192 is recruited to an adjacent seed element. The binding of HuR to the HuRBS prevents the recruitment of Argonaute 2 (Ago2), overriding miR-1192-mediated translation inhibition. Depleting HuR reduces myoblast fusion and silencing miR-1192 re-establishes the fusion potential of HuR-depleted cells. We propose that HuR promotes the commitment of myoblasts to myogenesis by enhancing the translation of HMGB1 and suppressing the translation inhibition mediated by miR-1192. RNA content was extracted following immunoprecipitation of HuR using a monoclonal antibody (3A2) and the levels of mRNA were compared to an IgG control in order to determine which transcripts were enriched in the HuR ribonucleoprotein complex.
Project description:Mycobacterium tuberculosis is the causative agent of tuberculosis, a disease that affects one-third of the world’s population. The sole extant vaccine for tuberculosis is the live attenuated Mycobacterium bovis bacille Calmette-Guerin (BCG). We examined 13 representative BCG strains from around the world to ascertain their ability to express DosR-regulated dormancy antigens. These are known to be recognized by T-cells of M. tuberculosis infected individuals, especially those harboring latent infections. Differences in expression of these antigens could be valuable for use as diagnostic markers to distinguish BCG vaccination from latent tuberculosis. We determined that all BCG strains were defective for induction of two dormancy genes, narK2 (Rv1737c) and narX (Rv1736c). NarK2 is known to be necessary for nitrate respiration during anaerobic dormancy. Analysis of the narK2/X promoter region revealed a base substitution mutation in all tested BCG strains and M. bovis in comparison to the M. tuberculosis sequence. We also show that nitrate reduction by BCG strains during dormancy was greatly reduced compared to M. tuberculosis and varied between tested strains. Several dormancy regulon transcriptional differences were also identified among the strains, as well as variation in their growth and survival. These findings demonstrate defects in DosR regulon expression during dormancy and phenotypic variation between commonly used BCG vaccine strains. 12 different BCG strains were examined as well as M. tuberculosis H37Rv and M. bovis. Two arrays per strain were analyzed, one with the addition of nitric oxide and the other utilizing hypoxia treatment, both conditions shown to induce expression of the dormancy regulon. The reference sample for each array was log phase M. tuberculosis H37Rv.
Project description:Oryza sativa cv. Nipponbare was engineered to over-express a barley alanine aminotransferase (alaAT) gene using the promoter (OsANT1) from a rice aldehyde dehydrogenase gene that expresses in roots. We use biotechnology to improve the nitrogen use efficiency of rice by over-expressing alaAT in a tissue specific (root) manner. The AlaAT enzyme is a reversible aminotransferase that is linked to both C and N metabolism since it uses pyruvate plus glutamate to produce alanine and 2-oxoglutarate, and visa versa. Transcriptome data from the roots and shoots of rice plants at maximum tillering, grown hydroponically on either 0.5, 2 or 5 mM NH4+ as the nitrogen source. Wildtype rice (Nipponbare) and two independent OsANT1:HvAlaAT rice transgenic lines (AGR1/7, and AGR3/8) were grown hydroponically with either 0.5, 2 or 5mM NH4+ as the nitrogen source, to the reproductive stage. Tissue samples were taken at active and maximum tillering from root and shoot, at mid-day of the plants' day/night cycle. The RNA from root and shoot at maxiumum tillering was used for mcroarray analysis. Please read Beatty et al., 2009, PLant Biotechnology Journal 7, pp562-576 for detailed about these transgenic lines. The results from this variable N study were reported in a manuscript submitted to Botany, July 2013
Project description:In order to understand the cellular mechanisms that facilitate a surface-associated lifestyle, expression profiles were determined at the levels of transcription and translation for sessile and planktonic Campylobacter jejuni NCTC 11168 (obtained from American Type Culture Collection (ATCC 700819)). These investigations indicate that the immobilized bacteria undergo a shift in cellular priorities away from metabolic, motility and protein synthesis capabilities towards emphasis on iron uptake, oxidative stress defense and membrane transport. Growth in broth was achieved by transferring stock culture to MH broth in tissue culture flasks and incubated microaerobically. Growth on agar was achieved by transferring stock culture onto MH agar plates, spreading the culture to produce a lawn, and incubation microaerobically. Cell densities in both growth conditions increased steadily up to 12 hrs and maximum cell densities were achieved at 18 hrs following which cell death starts to occur. Thus based on the growth curve C. jejuni cells at 16 hrs of incubation were used in all studies.
Project description:Background: TrkB-T1 is a BDNF receptor lacking a tyrosine kinase domain that is highly expressed in astrocytes and regulates BDNF-evoked calcium transients. Previous studies indicate that downregulation of TrkB-T1 in frontal cortex may be involved in neurobiological processes underlying suicide. Methods: In a microarray screening study (N=8), we interrogated all known microRNA in the frontal cortex of suicide completers with low expression of TrkB-T1 and normal controls. These findings were validated and followed up in a larger sample of cases and controls (N=55) Functional analyses included microRNA silencing, microRNA overexpression and luciferase assays to investigate specificity and to validate interactions between differentially expressed microRNA and TrkB-T1 Results: microRNAs Hsa-miR-185* and Hsa-miR-491-3p were upregulated in suicide completers with low expression of TrkB.T1 (Pnominal: 9.10-5 and 1.8.10-4 respectively; FDR-corrected p=0.031). Bioinformatic analyses revealed five putative binding sites for the DiGeorge syndrome linked microRNA Hsa-miR-185*in the 3’UTR of TrkB-T1, but none for Hsa-miR-491-3P. The increase of Hsa-miR-185* in frontal cortex of suicide completers was validated then confirmed in a larger, randomly selected group of suicide completers, where an inverse correlation between Hsa-miR-185* and TrkB-T1 expression was observed ( R=-0.404; p=0.002). Silencing and overexpression studies performed in human cell lines confirmed the inverse relationship between hsa-mir-185* and trkB-T1 expression. Luciferase assays demonstrated that Hsa-miR-185* binds to sequences in the 3’UTR of TrkB-T1. Conclusion: These results suggest that an increase of Hsa-miR-185* expression levels regulates, at least in part, the TrkB-T1 decrease observed in the frontal cortex of suicide completers and further implicate the 3MB 22q11 region in psychopathology. The microarray analysis consists in to compare the microRNA profile of four suicide completers with low TrkB-T1 expression level and four controls. Each RNA extract was labeled with Hy3 and hybridyzed with a reference sample labeled with Hy5. The reference sample was a pool of the eight RNA samples
Project description:This SuperSeries is composed of the following subset Series: GSE12278: MYC stimulates EZH2 expression by repression of its negative regulator miR-26a GSE12394: murine MYC-dependent lymphoma cells: Dox vs. NoDox treatment Refer to individual Series