Project description:The experiment was designed to identify the genes which get altered after over-expression and depletion of hsa-miR-195 levels in MCF7 and HEK 293T cells. Recent research has established that microRNAs (miRNAs) are key regulators of many cell processes including those often deregulated in cancer such as apoptosis. In our previous work we have shown that hsa-miR-195 targets the key anti-apoptotic molecule BCL2 and its over-expression induces apoptosis and augments sensitivity of cancer cells towards chemotherapeutic drug. These results suggested a possible anticancer role of miR-195 and therefore oblige its complete functional characterization. In this study global effect of alterations in cellular miR-195 levels on transcriptome was analysed in order to identify the regulatory functions of miR-195. Together our findings highlight a novel and important role of hsa-miR-195 potentially opening new avenues for the treatment of various diseases.
Project description:Tetrachloroethene (PCE) and trichloroethene (TCE) are prevalent groundwater contaminants that can be completely reductively dehalogenated by Dehalococcoides organisms. A Dehalococcoides-containing microbial consortium (ANAS) with the ability to degrade TCE to ethene, an innocuous end-product, was previously enriched from contaminated soil. A whole-genome photolithographic microarray was developed based on the genome of Dehalococcoides ethenogenes 195 (strain 195). This microarray contains probes designed to hybridize to >99% of the predicted protein-coding sequences in the strain 195 genome. DNA from ANAS was hybridized to the microarray to characterize the genomic content of the ANAS enrichment. The microarray revealed that the genes associated with central metabolism including an apparently incomplete carbon fixation pathway, cobalamin salvaging system, nitrogen fixation pathway, and five hydrogenase complexes are present in both strain 195 and ANAS. Although the gene encoding the TCE reductase tceA was detected, 13 of the 19 reductive dehalogenase genes present in strain 195 were not detected in ANAS. Additionally, 88% of the genes in predicted integrated genetic elements in strain 195 were not detected in ANAS, consistent with these elements being genetically mobile. Sections of the tryptophan operon and an operon encoding an ABC transporter in strain 195 were also not detected in ANAS. These insights into the diversity of Dehalococcoides genomes will improve our understanding of the physiology and evolution of these bacteria which is essential in developing effective strategies for bioremediation of PCE and TCE in the environment. Keywords: comparative genomic hybridization
Project description:Increased intestinal permeability is associated to the onset of inflammatory bowel disease (IBD) since the exposition to luminal content causes an immunological response that promotes intestinal inflammation. Several studies have been shown that microRNAs (miRNAs) are involved in IBD pathogenesis. Here, we aimed to functionally characterize the role of miRNAs in the regulation of intestinal permeability. miRNA profile of intestinal epithelial cells (IECs) isolated by colon of a UC mice model were identified using microarray. To predict the target genes of modulated miRNAs, we performed a bioinformatic analysis. To validate biologically miRNA targets, we performed transient transfection experiments in HT-29, Caco2 and T84 cell lines. To assess their role in barrier function, trans-epithelial electrical resistance and dextran flux assays were used. To investigate the in vivo effect of miR-195-5p, we employed a DSS-induced colitis model in mice. We identified 18 deregulated miRNAs in IECs from UC mice model and control mice. Among them, down-regulated miR-195-5p targeted CLDN2 and are involved in altered intestinal permeability. CLDN2 expression levels were increased in UC mice models and negatively correlated with the miR-195-5p expression. We demonstrated that the gain-of-function of miR-195-5p in colonic epithelial cell lines decreased the CLDN2 levels. We in vitro confirmed that miR-195-5p was able to control the intestinal barrier integrity. We also in vivo demonstrated that miR-195-5p attenuated the colonic inflammatory response in DSS-induced colitis and reduced the colonic permeability. All together our data support a previously unreported role of miR-195-5p in intestinal permeability and provide a potential pharmacological target for new therapeutic approaches in IBD.
Project description:To explore functionally crucial tumor-suppressive (TS)-miRNAs in hepatocellular carcinoma (HCC), we performed integrative function- and expression-based screenings of TS-miRNAs in six HCC cell lines. The screenings identified seven miRNAs, which showed growth-suppressive activities through the overexpression of each miRNA and were endogenously downregulated in HCC cell lines. Further expression analyses using a large panel of HCC cell lines and primary tumors demonstrated four miRNAs, miR-101, -195, -378 and -497, as candidate TS-miRNAs frequently silenced in HCCs. Among them, two clustered miRNAs miR-195 and miR-497 showed significant growth-suppressive activity with induction of G1 arrest. Comprehensive exploration of their targets using Argonute2-immunoprecipitation-deep-sequencing (Ago2-IP-seq) and genome-wide expression profiling after their overexpression, successfully identified a set of cell-cycle regulators, including CCNE1, CDC25A, CCND3, CDK4, and BTRC. Our results suggest the molecular pathway regulating cell cycle progression to be integrally altered by downregulation of miR-195 and miR-497 expression, leading to aberrant cell proliferation in hepatocarcinogenesis. Identification of miR-195 and miR-497 target genes by sequencing Ago2-binding mRNAs and total mRNAs of miR-195 or miR-497 overexpressed, or non-treated Hep G2 cell.
Project description:Despite considerable improvements in the treatment of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), relapse is still associated with poor prognosis. We previously found that the risk for early relapse can be predicted by the rapid engraftment of patient-derived blasts transplanted into NOD/SCID mice. In search for the cellular and molecular profile associated with this phenotype, we investigated the expression of microRNAs (miRNAs) in different engraftment phenotypes and patient outcomes. We found miR-497~195 high expression in patient-derived xenograft samples with slow engraftment, derived from patients with favorable outcome. In contrast, epigenetic repression and low expression of these miRNAs was observed in rapidly engrafting samples, which were associated with early relapse. Overexpression of miR-497~195 in patient-derived cells suppressed in vivo engraftment of leukemia cells and considerably prolonged recipient survival by inhibition of regulators of cell cycle progression. As key factors for the entry in S phase were downregulated upon miR-497~195 overexpression, we identified CDK4/CCND3 mediated control of G1/S transition as a principal mechanism for miR-497~195 mediated suppression of leukemia progression in BCP-ALL. Thus, the association of the miR-497~195 cluster expression with outcome in BCP-ALL, and the importance of these miRNAs in counteracting the development of ALL in vivo indicate the relevance of the involved pathways as potential targets for therapeutic intervention.
Project description:miRNAs are related with the initiation and development of prostate cancer. We discover the miR-195 and miR-30 can be as a biomarker of prognosis of prostate cancer in clinical patients. miRNA functions through affecting the mRNA degradation by binding the mRNA 3âUTR. So we test the change of transcriptional profile of miR-195 and miR-30d cell line respectively to further study the function of miR-195 and miR-30d. To study the function of miR-195 and miR-30d in prostate cancer, we setup the over-expression cell line of the miR-195 and miR-30d respectively in prostate cancer cell(LNCap and DU145), then study the change of transcriptional profile in cell line by microarray experiment (Affymetrix PrimeView human gene expression). We order the over-expression plasmid of vector, miR-195 and miR-30d from System Biosciences company (Cat No: Scramble Vector PMIRH000PA-1 as Control, miR-195 PMIRH195PA-1, miR-30d PMIRH30dPA-1), and packaged the virus and construct the stable cell line (LNCaP_Control, LNCaP_mir195, LNCaP_mir30d,DU145_Control, DU145_mir195, DU145_mir30d,). We test the transcriptional profile in cell line by microarray experiment (Affymetrix PrimeView human gene expression).
Project description:miRNAs are related with the initiation and development of prostate cancer. We discover the miR-195 and miR-30 can be as a biomarker of prognosis of prostate cancer in clinical patients. miRNA functions through affecting the mRNA degradation by binding the mRNA 3’UTR. So we test the change of transcriptional profile of miR-195 and miR-30d cell line respectively to further study the function of miR-195 and miR-30d. To study the function of miR-195 and miR-30d in prostate cancer, we setup the over-expression cell line of the miR-195 and miR-30d respectively in prostate cancer cell(LNCap and DU145), then study the change of transcriptional profile in cell line by microarray experiment (Affymetrix PrimeView human gene expression).
Project description:The chlorinated ethene-respiring bacteria of the genus Dehalococcoides are important for bioremediation. A microarray targeting genes from all available sequenced genomes of the Dehalococcoides genus was designed with 4305 probe sets to target 98.6% of all genes from strains 195, CBDB1, BAV1, and VS. The microarrays were validated with genomic DNA (gDNA) of strains 195 and BAV1 and satisfactory analytical reproducibility, quantitative response and gene detection accuracy were obtained. These microarrays were applied to query the genomes of two recently isolated Dehalococcoides strains, ANAS1 and ANAS2. Strains ANAS1 and ANAS2 can both couple the reduction of TCE, cDCE and 1,1-DCE but not PCE and tDCE with growth while only strain ANAS2 couples VC reduction to growth. Analysis of the respective gDNA using the microarrays showed that the genomes of both strains are similar to each other and to strain 195, except for genes that are within the previously defined integrated elements (IEs) or high plasticity regions (HPRs). Similar results to the combined isolates were obtained when gDNA of ANAS, the enrichment culture from which the two Dehalococcoides isolates originated, was applied to the microarrays. The genome similarities, together with the distinct chlorinated ethene usage of strains ANAS1, ANAS2 and 195 demonstrate that closely phylogenetically related strains can be physiologically different. This incongruence between physiology and core genome phylogeny appears to be driven by the presence of distinct reductive dehalogenase (RDase)-encoding genes with characterized chlorinated ethene functions (pceA, tceA in strain 195; tceA in strain ANAS1; vcrA in strain ANAS2). Genes encoding central metabolic functions of strain 195 were all detected in strains ANAS1 and ANAS2, while interestingly, the tryptophan operon of these strains is similar to that of strain VS. Overall, the microarrays are a valuable high-throughput tool for comparative genomics of un-sequenced Dehalococcoides-containing samples.
Project description:The syntrophic growth of strain 195 with Desulfovibrio vulgaris Hildenborough (DVH) and/or Methanobacterium congolense (MC) enhanced TCE dechlorination process by faster dechlorination rate and more robust growth. Transcriptomes of strain 195 grown in isolation, co- and tri-cultures were obtained by microarray experiments to find out the differential expressed genes corresponding to the syntrophic growth. Thus we can better understand the role of DVH and MC within this syntrophy. [Transcriptomic analysis]: Cells of pure strain 195 culture, co-culture and tri-culture were collected at the early exponential phase during TCE dechlorination process for RNA extraction, cDNA synthesis, fragmentation, labelling, and hybridization on microarray. We sought to obtain differential transcription of 195 genes in pure, co- and tri- cultures, in order to understand the role of DVH and MC in the syntrophy of strain 195.
Project description:To explore functionally crucial tumor-suppressive (TS)-miRNAs in hepatocellular carcinoma (HCC), we performed integrative function- and expression-based screenings of TS-miRNAs in six HCC cell lines. The screenings identified seven miRNAs, which showed growth-suppressive activities through the overexpression of each miRNA and were endogenously downregulated in HCC cell lines. Further expression analyses using a large panel of HCC cell lines and primary tumors demonstrated four miRNAs, miR-101, -195, -378 and -497, as candidate TS-miRNAs frequently silenced in HCCs. Among them, two clustered miRNAs miR-195 and miR-497 showed significant growth-suppressive activity with induction of G1 arrest. Comprehensive exploration of their targets using Argonute2-immunoprecipitation-deep-sequencing (Ago2-IP-seq) and genome-wide expression profiling after their overexpression, successfully identified a set of cell-cycle regulators, including CCNE1, CDC25A, CCND3, CDK4, and BTRC. Our results suggest the molecular pathway regulating cell cycle progression to be integrally altered by downregulation of miR-195 and miR-497 expression, leading to aberrant cell proliferation in hepatocarcinogenesis. Analysis of miRNA profile change in the Ago2-IP fraction after overexpression with miR-195 or miR-497