Project description:To identify which miR-148b targets were involved in tumorigenesis, a microarray analysis was performed for miR-148b over-expressing cells versus controls and 129 (49 up and 80 down) modulated genes were revealed. The effects of miR-148b on cancer progression depend on the direct and indirect regulation of multiple target genes. To identify miR-148b modulated genes, MDA-MB-231 cells were transfected with miR-148b precursors or negative controls (pre-miR-148b or control) and used 48h later for microarray and western blot (WB) analyses. When a âWhole Human Genome Oligo Microarrayâ (Agilent) platform was employed, 129 differentially expressed genes (49 upregulated, 80 downmodulated) were found at 48h, considering a fold change (FC) cut of 1.5 and a false discovery rate (FDR) of 16% (Table S4). Crossing these results with the list of putative miR-148b targets (3642) obtained by the miRecords System, we observed that 33 of the modulated genes were also miR-148b predicted targets and interestingly, 26 out of these 33 genes were downmodulated.
Project description:Immunoglobulin A nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide characterized by aberrant O-glycosylation in the hinge region of IgA1. The basis for the abnormal glycosylation in IgAN is still unknown, but an important involvement of the enzyme core 1, beta 1,3-galactosyltransferase 1 (C1GALT1) is known. However, the role of microRNAs (miRNAs), a new family of key mRNA regulatory molecules, in the IgAN pathogenesis has not yet been reported. In this study, by high-throughput microRNA profiling, we identified 37 miRNAs differentially expressed in peripheral blood mononuclear cells (PBMCs) from IgAN patients compared to healthy subjects. Among them, upregulated miR-148b potentially targeted C1GALT1, INVS and PTEN, three genes notably downregulated in IgAN patients. C1GALT1 expression levels in IgAN patients were reduced and negatively correlated with the upregulated miR-148b expression. We demonstrated the biological relationship between miR-148b and C1GALT1 by transient transfection experiments ex vivo. When we reduced the upregulated miR-148b function in PBMCs of IgAN patients an increase of the C1GALT1 mRNA and protein levels was observed. We validated biologically also the miR-148b targeting of INVS , involved in the altered modulation of the WNT–β-catenin and PI3K/Akt pathways in IgAN patients. All together our data evidence an important role of miR-148b in the pathogenesis of IgAN, which could explain the aberrant glycosylation of IgA1 in the pathogenesis and should light on a potential target for the theraphy of the disease.
Project description:To identify which miR-148b targets were involved in tumorigenesis, a microarray analysis was performed for miR-148b over-expressing cells versus controls and 129 (49 up and 80 down) modulated genes were revealed.
Project description:Background/Objective: Quantitative real-time PCR (RT-qPCR) is widely used in miRNA expression studies on cancer. To compensate for the analytical variability produced by the multiple steps of the method, relative quantification of the measured miRNAs is required, which is based on normalization to endogenous reference genes. A literature search in PubMed revealed that no study has been performed so far on reference miRNAs for normalization of miRNA expression in urothelial carcinoma. The aim of this study was to identify suitable reference genes for miRNA expression studies by RT-qPCR in urothelial carcinoma. Methods: Candidate reference miRNAs were selected from 24 papillary urothelial carcinoma and normal bladder tissue samples by miRNA microarrays. The usefulness of these candidate reference miRNAs together with the commonly for normalization purposes used small nuclear RNAs RNU6B, RNU48, and Z30 were thereafter validated by RT-qPCR in 58 tissue samples and analyzed by the algorithms geNorm, NormFinder, and BestKeeper. Principal Findings: Based on the miRNA microarray data, a total of 16 miRNAs were identified as putative reference genes. After validation by RT-qPCR, miR-101, miR-125a-5p, miR-148b, miR-151-3p, miR-151-5p, miR-181a, miR-181b miR-29c, miR-324-3p, miR-424, miR-874, RNU6B, RNU48, and Z30 were used for geNorm, NormFinder, and BestKeeper analyses that gave different combinations of recommended reference genes for normalization. Conclusions: The present study provided the first systematic analysis for identifying suitable reference miRNAs for miRNA expression studies of urothelial carcinoma by RT-qPCR. Different combinations of reference genes resulted in reliable expression data for both strongly and less strongly altered miRNAs. Notably, RNU6B, which is the most frequently used reference gene for miRNA studies, gave inaccurate normalization. The combination of four (miR-125a-5p, miR-148b, miR-151-3p, and miR-151-5p) or three (miR-148b, miR-874, miR-181b) miRNA reference genes is recommended for normalization.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes