Project description:The microarray gene expression analysis revealed that TCF-4 isoforms activate different downstream target genes in HCC. TCF-4J upregulated genes associated with Wnt/beta-catenin, Notch, and insulin/IGF-1/IRS1 signal transduction pathway.
Project description:During canonical Wnt signalling the activity of nuclear beta-catenin is largely mediated by the TCF/LEF family of transcription factors. To challenge this view we used the CRISPR/Cas9 genome editing approach to generate HEK 293T cell clones simultaneously carrying loss-of-function alleles of all four TCF/LEF genes. Exploiting unbiased whole transcriptome sequencing studies, we found that a subset of beta-catenin transcriptional targets did not require TCF/LEF factors for their regulation. Consistent with this finding, we observed in a genome-wide analysis that beta-catenin occupied specific genomic regions in the absence of TCF/LEF. Finally, we revealed the existence of a transcriptional activity of beta-catenin that specifically appears when TCF/LEF factors are absent, and refer to this as beta-catenin-GHOST response. Collectively, this study uncovers a previously neglected modus operandi of beta-catenin that bypasses the TCF/LEF transcription factors.
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:The DNA binding factor Tcf-1 is one of the most prominently expressed genes in thymocytes yet it's global DNA binding pattern remained unknown. Here we have assessed by ChIP-seq the Tcf-1 binding pattern in murine thymocytes. Tcf-1 ChIP-seq of 1 sample and input control.
Project description:Mutations in several transcription factors lead to a subtype of type 2 diabetes called maturity-onset diabetes of the young (MODY), which are characterized by autosomal dominant inheritance, an early age of disease onset, and development of marked hyperglycemia with a progressive impairment in insulin secretion (Shih and Stoffel, 2002). The most frequent form of MODY is caused by mutations in the gene encoding hepatocyte nuclear factor-1a (HNF-1a, TCF1). Mutant mice with loss of Tcf1 function as well as transgenic mice expressing a naturally occurring dominant-negative form of human TCF1(P291fsinsC) in pancreatic beta cells develop progressive hyperglycemia due to impaired glucose-stimulated insulin secretion (Hagenfeldt-Johansson et al., 2001; Yamagata et al., 2002). Importantly, these mice exhibit a progressive reduction in beta cell number, proliferation rate, and pancreatic insulin content. These data indicate that Tcf-1 target genes are also required for maintenance of normal beta cell mass. In this study we sought to identify target genes of Tcf-1 that may be responsible of mediating beta cell growth by comparing gene expression profiles of Tcf-1 knock-out and wild-type littermates in isolated pancreatic islets.
Project description:In development, pioneer transcription factors access silent chromatin to reveal lineage-specific gene programs. The structured DNA-binding domains of pioneer factors have been well characterized, but whether and how low-complexity intrinsically disordered regions (IDRs) affect chromatin and control cell fate is unclear. Here, we report deletion of an IDR of the pioneer factor TCF-1, termed “L1”, leads to an early developmental block in T cells. The few T cells that develop from progenitors expressing TCF-1 lacking L1 exhibit lineage infidelity distinct from the lineage diversion of TCF-1 deficient cells. Mechanistically, L1 is required for activation of T cell genes and de-repression of GATA2 driven genes, normally reserved to the mast cell and dendritic cell lineages. Underlying this lineage diversion, L1 mediates binding of TCF-1 to its earliest target genes which are subject to repression as T cells develop. These data suggest TCF-1’s intrinsically disordered N-terminus maintains T cell lineage fidelity.
Project description:The DNA binding factor Tcf-1 is one of the most prominently expressed genes in thymocytes yet its global DNA binding pattern remained unknown. Here we have assessed by ChIP-seq the Tcf-1 binding pattern in murine thymocytes in WT B6 mice and in mice expressing a stabilized form of the Tcf-1 binding partner beta-Catenin (CAT mice).
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:Huntington's Disease (HD) is an inherited neurodegenerative disease caused by a glutamine repeat expansion in huntingtin protein. Transcriptional deregulation and altered energy metabolism have been implicated in HD pathogenesis. We report here that mutant huntingtin causes disruption of mitochondrial function by inhibiting expression of PGC-1a, a transcriptional coactivator that regulates several metabolic processes including mitochondrial biogenesis and respiration. Mutant huntingtin represses PGC-1a gene transcription by associating with the promoter and interfering with the CREB/TAF4-dependent transcriptional pathway critical for the regulation of PGC-1a gene expression. Crossbreeding of PGC-1a knockout mice with HD knock-in mice leads to increased neurodegeneration of striatal neurons and motor abnormalities in the HD mice. Importantly, expression of PGC-1a partially reverses the toxic effects of mutant huntingtin in cultured striatal neurons. Moreover, lentiviral-mediated delivery of PGC-1a in the striatum provides neuroprotection in the transgenic HD mice. These studies suggest a key role for PGC-1a in the control of energy metabolism in the early stages of HD pathogenesis. Experiment Overall Design: Total RNA was extracted from striata of 3 pgc1 KO mice and 3 littermate controls using the RNeasy Mini Kit (Qiagen) according to manufacturer's protocol. Samples were analyzed using RNA 6000 Nano LabChip kit on a 2100 Bioanalyzer (Agilent Technologies) to ensure integrity of RNA.
Project description:T Cell Factor-1, encoded by TCF-7, is a transcription factor that plays an essential role during T cell development and differentiation. In this manuscript we utilized a pre-clinical model provided evidence that TCF-7 is dispensable for the anti-tumor response, and that TCF-7 suppresses key transcriptional factors Eomes and T-bet and molecules responsible for peripheral CD8 T cell cytolytic function. We discovered that TCF-7 regulates NKG2D expression on naïve and activated mouse CD8 T cells, and that peripheral CD8 T cells from TCF-7 cKO utilize NKG2D to clear tumor cells. We also provide evidence that TCF-7 regulates key signaling molecules, including LCK, LAT, ITK, PLC-y1, P65, ERKI/II, and JAK/STATs required for peripheral CD8 T cell persistent function. Our data transcriptomic and protein data uncovered the mechanism of how TCF-7 impacting peripheral CD8 T cell inflammatory cytokine production, CD8 T cell activation, and apoptosis. Our pre-clinical model showed that CD8 T cells from TCF-7 cKO mice did not cause GVHD, but effectively cleared primary tumor cells.