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:NK-cell lymphoma shares strikingly similar molecular features with a distinct subset of gamma-delta T-cell lymphoma. Gene expression profiling of NK-cell lymphoma patient samples was performed to investigate whether molecular signatures can be used to identify entities of peripheral T-cell lymphoma (PTCL) with NK-cell-like features. Gene expression profiling was performed on NK-cell maligancies to examine extranodal NK/T-cell lymphoma (ENKTL) and aggressive NK-cell leukemia (ANKL) and well-characterized cell lines of NK- and T-cell lineages to define molecular classifiers that can distinguish ENKTL from other lymphomas.
Project description:NK-cell lymphoma shares strikingly similar molecular features with a distinct subset of gamma-delta T-cell lymphoma. Gene expression profiling of NK-cell lymphoma patient samples was performed to investigate whether molecular signatures can be used to identify entities of peripheral T-cell lymphoma (PTCL) with NK-cell-like features.
Project description:We performed a comprehensive genome-wide miRNA expression profiling (MEP) of extranodal nasal-type Natural Killer/T-cell lymphoma (NKTL) using formalin fixed paraffin-embedded tissue (FFPE) (n=30) and NK cell lines (n=6) in comparison with normal NK cells, with the objective of understanding the pathogenetic role of miRNA deregulation in NKTL.
