Project description:Sezary syndrome is an aggressive cutaneous T cell lymphoma with pruritic skin inflammation and immune dysfunction, driven by neoplastic, clonal memory T cells in both peripheral blood and skin. To gain insight into how abnormal gene expression in Sezary syndrome promotes T cell dysfunction, lymphoproliferation and transformation, we first compared functional transcriptomic profiles of both resting and activated memory T cells from Sezary syndrome patients and normal donors. To differentiate gene expression associated with malignancy vs. benign inflammation and proliferation, we performed a within-platform meta-analysis of our data for Sezary syndrome and a GEO data set (GSE12079) for lymphocytic variant hypereosinophilic syndrome (L-HES). L-HES is a benign lymphoproliferation of clonal memory T cells that produces skin symptoms very similar to Sezary syndrome. This approach revealed gene expression changes unique to either Sezary syndrome or L-HES, and a subset of genes dysregulated in both SS and L-HES. L-HES patient 1 progressed to peripheral T cell lymphoma, and acquired Sezary-like gene expression during progression, suggesting that these genes contribute to neoplastic transformation.
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:Comparative transcriptome profiles of patient-derived Sezary cells and cultured Sezary cell line (Hut78) mycosis fungoides cell line (Hut 102) and non-Sezary T cell leukemia cell line (Jurkat) relative to benign CD4+ T cells from individuals with no T cell malignancy. There are three goals. The first and primary goal is to establish a list of genes with differential expression between Sezary cells and the benign CD4+ T cell counter part from individuals without Sezary syndrome. A secondary goal is to examine if these differentially expresses genes in clinical samples of Sezary cells are preserved in Hut78 and Hut102 cells, which are the two most frequently used experimental cell models of Sezary cells in the research community. The third goal is to examine if these Sezary cell specific genes are also present in a non-Sezary T cell malignancy, such as Jurkat cells, which is derived from a non-Sezary cell T cell leukemia patient. Two color experiment, 6 biological replicates (6 unique patients) with Sezary syndrome, 1 Hut78 cell,1 Hut102 cell and 1 Jurkat cell lines as the experimental samples, each compared with a distinct individual with no T cell malignancy of the skin or the blood.
