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
Project description:Histone deacetylase (HDAC) inhibitors are part of a new generation of epigenetic drugs for cancer treatment. It is known that histone acetylation plays a key role in controlling essential chromosome functions, including gene regulation, and this process has been linked with cancer development and progression. Better understanding of molecular mechanisms involving HDAC inhibitors is needed for the design of new targeted drugs, and also to evaluate the effectiveness of current treatments. In this study, an untargeted metabolomics approach was used to identify intracellular metabolite deregulation after treating cancer cell lines with the HDAC inhibitor HC-Toxin. Metabolomics analysis was performed using high resolution mass spectrometry, in combination with univariate and multivariate statistics and pathway analysis. HDAC inhibition showed highly specific metabolic changes in cancer cell lines compared to non-cancerous cells. In particular, N-acetyl-L-cysteine, N-acetylmethionine, and N-acetyl-L-carnitine showed a dose dependent change. Moreover, pathways controlling protein biosynthesis, as well as tryptophan, cysteine and methionine metabolism were significantly altered by HDAC inhibition. This study illustrates that HDAC inhibition has multiple effects on different metabolic pathways and our results can be extrapolated to inform on the molecular transitions in human cells.
Project description:To investigate whether microRNAs (miRNAs) were induced by histone deacetylase inhibitors (HDACi) in human gastric cancer cells, the miRNA-seq was used to screen differentially expressed miRNAs in two human gastric cancer cell lines (HGC-27 and AGS) treated with the HDACi vorinostat (SAHA) or vehicle (DMSO).
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 Sequence library of miRNAs from a single sample of human foetal mesenchymal stem cells. Results tested and confirmed by northern blotting. Please note that only raw data files are available for the embryonic and neual samples and thus, directly submitted to SRA (SRX547311, SRX548700, respectively under SRP042115/PRJNA247767)