Project description:TCF-1 is an HMG family transcription factor which is known to be critical for T cell development. We discovered that it has a unique role in suppressing malignant transformation of developing thymocytes at early stages. We identified ID2 and LEF-1 as key TCF-1 target genens in tumor suppression. We used microarrays to detect gene expression changes in WT and TCF-1 deficient DN3 thymocytes as well as T cell lymphoma cells developed in TCF-1 KO mice. DN3 thymocytes were directly sorted from WT or TCF-1 KO mice. T cell lymphoma blast cells were also sorted from TCF-1 KO mice that developed the disease. RNA was extracted and hybridized to GeneChip Mouse GENE 1.0 ST arrays (Affymetrix).
Project description:TCF-1 is an HMG family transcription factor which is known to be critical for T cell development. We discovered that it has a unique role in suppressing malignant transformation of developing thymocytes at early stages. We identified ID2 and LEF-1 as key TCF-1 target genens in tumor suppression. We used microarrays to detect gene expression changes in WT and TCF-1 deficient DN3 thymocytes as well as T cell lymphoma cells developed in TCF-1 KO mice.
Project description:Both TCF-1 and its coactivator β-catenin are known to be required for supporting normal double positive (DP) thymocyte survival through upregulating Bcl-xL. However, the downstream factors mediating this effect remained unknown. We used microarray to compare the global expression difference among WT, TCF-1-deficient, and β-catenin transgenic thymocytes to search for the genes that are down-regulated and up-regulated in TCF-1-deficient and β-catenin transgenic thymocytes, respectively.
Project description:Both TCF-1 and its coactivator β-catenin are known to be required for supporting normal double positive (DP) thymocyte survival through upregulating Bcl-xL. However, the downstream factors mediating this effect remained unknown. We used microarray to compare the global expression difference among WT, TCF-1-deficient, and β-catenin transgenic thymocytes to search for the genes that are down-regulated and up-regulated in TCF-1-deficient and β-catenin transgenic thymocytes, respectively. We focus on the genes that are significantly down-regulated and up-regulated in TCF-1-deficient and β-catenin transgenic thymocytes, respectively, to select for those genes that are potential target genes of β-catenin/TCF-1 pathway. And then those genes are subject to IPA pathway analysis searching for genes that are involved in thymocyte development and cell death.
Project description:Lineage negative, CD44 negative, CD25 positive thymocytes were isolated from wt mice or Miz1 POZ-domain knockout mice to analyze the effect of loss of Miz1 in the DN3 population of T-cells We used the mouse Affymetrix MOE430-2 microarray to characterize global gene expression changes of DN3 thymocytes from Miz1 knockout mice. We performed microarray based gene expression profiling to determine the effect of loss of Miz1 activity on the gene expression pattern of mouse DN3 thymocytes from wt and Miz1-delta-POZ mice.
Project description:T cell development is accompanied by epigenetic changes that ensure the silencing of stem cell-related, and the activation of lymphocyte-specific programs. How transcription factors influence these changes remains unclear. We show that the Ikaros transcription factor interacts with the Polycomb Repressive Complex 2 (PRC2) in CD4-CD8- thymocytes, and allows its binding to >200 developmentally-regulated genes, many of which are expressed in hematopoietic stem cells. Loss of Ikaros in CD4-CD8- cells leads to diminished histone H3 Lys27 (H3K27) trimethylation and ectopic expression of these genes. Ikaros binding triggers PRC2 recruitment and H3K27 trimethylation. Furthermore, Ikaros interacts with PRC2 independently of the Nucleosome Remodeling and Deacetylation complex. Our results identify Ikaros as a fundamental regulator of PRC2 function in developing T cells. Genome-wide comparison of different histone modifications, Ikaros, Suz12 and NuRD binding in different stages of T cell development in WT and Ikaros mutant mice. Profiling of H3K27me3 in DN1, DN2, DN3, DN4 and DP thymocytes and hematopoietic stem and progenitor cells (LSK cells) of WT and Ikaros mutant mice. Profiling of H3K4me3 and H3ac in WT and Ikaros mutant DP thymocytes. Global analysis of Ikaros binding in WT DN3, DN4 and DP cells, Suz12 binding in WT and Ikaros mutant DN3 cells, and Mta2 and Mi2beta binding in WT DN3 cells. Genome-wide profiling of Ikaros binding and H3K27me3 upon Ikaros activation in Ikaros-deficient leukemic T cells.