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:Sézary syndrome (SS) is a rare variant of primary cutaneous T-cell lymphoma. Little is known about the underlying pathogenesis of S. To address this issue, we used Affymetrix 10K SNP microarray to analyse 13 DNA samples isolated from 8 SS patients and qPCR with ABI TaqMan SNP genotyping assays for the validation of the SNP microarray results. In addition, we tested the impact of SNP loss of heterozygosity (LOH) identified in SS cases on the gene expression profiles of SS cases detected with Affymetrix GeneChip U133A. The results showed: (1) frequent SNP copy number change and LOH involving 1, 2p, 3, 4q, 5q, 6, 7p, 8, 9, 10, 11, 12q, 13, 14, 16q, 17, and 20, (2) reduced SNP copy number at FAT gene (4q35) in 75% of SS cases, and (3) the separation of all SS cases from normal control samples by SNP LOH gene clusters at chromosome regions of 9q31q34, 10p11q26, and 13q11q12. These findings provide some intriguing information for our current understanding of the molecular pathogenesis of this tumour and suggest the possibility of presence of functional SNP LOH in SS tumour cells.
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.
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.
Project description:Sezary syndrome (SS) is a rare, aggressive leukemic variant of cutaneous T cell lymphoma (CTCL) that lacks adequate therapeutic options and representative small animal models. Here we demonstrate that IL-15 is a critical CTCL growth and survival factor. Importantly, a genetically engineered immunodeficient mouse model expressing human IL-15 uniquely supported the growth of patient derived Sezary cells relative to conventional immunodeficient mouse strains. Patient derived xenograft (PDX) SS models recapacitated the pathologic features of the human disease, including skin infiltration and spread of leukemic cells to the periphery, and maintained the dependence on human IL-15 upon serial in vivo passaging. Detailed molecular characterization of the engrafted cells by single cell transcriptome analysis revealed tissue specific regulation of gene expression and distinct clonal engraftment patterns. Overall, we document an important dependence of Sezary cell survival and proliferation on IL-15 signaling and the utility of the humanized IL-15, immunodeficient mice for SS PDX model generation. Furthermore, these studies advocate for the thorough molecular understanding of the resultant PDX models to maximize their translational impact.
Project description:Sezary syndrome (SS) is a rare, aggressive leukemic variant of cutaneous T cell lymphoma (CTCL) that lacks adequate therapeutic options and representative small animal models. Here we demonstrate that IL-15 is a critical CTCL growth and survival factor. Importantly, a genetically engineered immunodeficient mouse model expressing human IL-15 uniquely supported the growth of patient derived Sezary cells relative to conventional immunodeficient mouse strains. Patient derived xenograft (PDX) SS models recapacitated the pathologic features of the human disease, including skin infiltration and spread of leukemic cells to the periphery, and maintained the dependence on human IL-15 upon serial in vivo passaging. Detailed molecular characterization of the engrafted cells by single cell transcriptome analysis revealed tissue specific regulation of gene expression and distinct clonal engraftment patterns. Overall, we document an important dependence of Sezary cell survival and proliferation on IL-15 signaling and the utility of the humanized IL-15, immunodeficient mice for SS PDX model generation. Furthermore, these studies advocate for the thorough molecular understanding of the resultant PDX models to maximize their translational impact.
Project description:<p>Sezary syndrome is a leukemic and aggressive form of cutaneous T-cell lymphoma (CTCL) resulting from the malignant transformation of skin-homing central memory CD4+ T cells. To identify new genetic alterations involved in Sezary syndrome and CTCL transformation we performed whole-exome sequencing of tumor-normal sample pairs from 26 Sezary syndrome and 16 CTCL patients. These analyses revealed a distinctive pattern of somatic copy number alterations in Sezary syndrome including highly prevalent recurrent chromosomal deletions involving the TP53, RB1, PTEN, DNMT3A, and CDKN1B tumor suppressor genes. Mutation analysis identified a broad spectrum of somatic mutations involving key genes involved in epigenetic regulation (TET2, CREBBP, MLL3, BRD9, SMARCA4 and CHD3) and signaling, including mutations in MAPK1, BRAF, CARD11 and PRKG1 driving increased MAPK, NFKB and NFAT activity upon T-cell receptor stimulation. Collectively, our findings provide new insights into the genetics of Sezary syndrome and CTCL and support the development of personalized therapies targeting key oncogenically activated signaling pathways for the treatment of these diseases.</p>
Project description:AHI-1 is an oncogene often targeted by provirus insertional mutagenesis in murine leukemias and lymphomas. Aberrant expression of human AHI-1 occurs in cutaneous T-cell lymphoma (CTCL) cells and in CD4+CD7- Sezary cells from patients with Sezary syndrome (SS). Stable knockdown of AHI-1 using retroviral-mediated RNA interference in CTCL cells inhibits their transforming activity in vitro and in vivo. To identify genes involved in AHI-1-mediated transformation, microarray analysis was performed to identify differentially expressed genes in AHI-1 suppressed CTCL cells. Fifteen up-regulated and six down-regulated genes were identified and confirmed by Q-RT-PCR. Seven were further confirmed in a microarray analysis of CD4+CD7- Sezary cells from SS patients. HCK and BIN1 emerged as new candidate cooperative genes, with differential protein expression which correlates with observed transcript changes. Interestingly, changes in HCK phosphorylation and biological response to its inhibitor, dasatinib, were observed in AHI-1 suppressed or overexpressed cells. The tumor suppressor BIN1 physically interacts with MYC in CTCL cells, which also exhibit differential MYC protein expression. In addition, aberrant expression of alternative splicing forms of BIN1 was observed in primary and transformed CTCL cells. These findings indicate that HCK and BIN1 may play critical roles in AHI-1-mediated leukemic transformation of human CTCL cells. Experiment Overall Design: Two groups, each with two subgroups, subgroups having 2 or 3 replicates each