Project description:Cellular changes during an epithelial-mesenchymal transition (EMT) largely rely on global changes in gene expression orchestrated by transcription factors. Tead transcription factors and their co-factors Yap and Taz have been shown to be implicated in EMT, nevertheless, their direct target genes during EMT have remained elusive.We used genome-wide chromatin immunoprecipitation and next generation sequencing to identify diect Tead2 target genes during EMT. Py2T cells (murine breast cancer cell line) were treated with TGFβ for 5 days and subjected to ChIP using an antibody for Tead2 followed by next generation sequencing (Illumina HiSeq 2000; n=2)
Project description:Cellular changes during an epithelial-mesenchymal transition (EMT) largely rely on global changes in gene expression orchestrated by transcription factors. Tead transcription factors and their co-factors Yap and Taz have been shown to be implicated in EMT, nevertheless, their direct target genes during EMT have remained elusive.We used genome-wide chromatin immunoprecipitation and next generation sequencing to identify diect Tead2 target genes during EMT.
Project description:The Hippo pathway effectors yes-associated protein (YAP) and WW domain containing transcription regulator 1 (TAZ/WWTR1) support tumor initiation and progression in various cancer entities including hepatocellular carcinoma (HCC). However, to which extent YAP and TAZ contribute to liver tumorigenesis via common and exclusive molecular mechanisms is poorly understood. RNAinterference (RNAi) experiments illustrate that YAP and TAZ individually support HCC cell viability and migration, while for invasion additive effects were observed. Comprehensive expression profiling revealed partly overlapping YAP/TAZ target genes as well as exclusively regulated genes.
Project description:HCC is a highly vascular tumor, and many effective drug regimens target the tumor blood vessels. Prior bulk HCC subtyping data used bulk transcriptomes, which contained a mixture of parenchymal and stromal contributions. Using cell type–specific spatial transcriptomics techniques to separate cancer cells and endothelial cells applied to a set of 41 resected HCC tissue specimens, we report that the prior Hoshida bulk transcriptional subtyping schema is driven largely by an endothelial fraction, show an alternative tumor-specific schema has potential prognostic value, and use spatially paired ligand-receptor analyses to identify known and novel (LGALS9 tumor-HAVCR2 vessel) signaling relationships that drive HCC biology in a subtype-specific and potentially targetable manner. Our study leverages spatial gene expression profiling technologies to dissect HCC heterogeneity and identify heterogeneous sig- naling relationships between cancer cells and their endothelial cells. Future validation and expansion of these findings may validate novel cancer- endothelial cell interactions and related drug targets.
Project description:Background & Aims: Succinate dehydrogenase enzyme (SDH) is frequently found to be diminished in Hepatocellular carcinoma (HCC) patient samples, and SDH reduction is associated with elevated succinate level and poor prognosis in HCC patients. But the underlying mechanisms about how impaired SDH activity promotes HCC malignancy remain unclear. Approach & Results: In this study, we observed remarkable downregulations of SDH subunits A and B (SDHA/B) in chronic liver injury-induced murine HCC models and HCC patient samples. Subsequent RNA sequencing, hematoxylin & eosin (H&E) staining and immunohistochemistry (IHC) analyses of HCC samples revealed that Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) were significantly upregulated in HCC, with their levels inversely correlating with that of SDHA/B. The protein stability of YAP/TAZ was greatly enhanced in SDHA/B-depleted HCC cells along with accumulation of succinate. Further mechanistic analyses demonstrated that impaired activity of SDHA/B resulted in succinate accumulation which facilitated the removal of NEDDylation on cullin1, therefore disrupted the E3 ubiquitin ligase SCFβ-TrCP complex, consequently led to YAP/TAZ stabilization and activation in HCC cells. The accelerated in vitro cell proliferation and in vivo tumor growth caused by SDHA/B reduction or succinate exposure were largely dependent on the aberrant activation of YAP/TAZ. Conclusions: Our study demonstrated that SDHA/B reduction promotes HCC proliferation by preventing the proteasomal degradation of YAP/TAZ through modulating cullin1 NEDDylation, thus addicts SDH-deficient HCC cells to YAP/TAZ pathway and renders these cells vulnerable to YAP/TAZ inhibition. Our findings warrant further investigation on the therapeutic effects of targeting YAP/TAZ in HCC patients displaying reduced SDHA/B or elevated succinate levels.
Project description:The Hippo signaling pathway is evolutionarily well conserved, and all core components have one or more mammalian orthologs, including MST1/2 (Hippo), SAV1 (Salvador), LATS1/2 (Warts), MOB1 (Mats), YAP1/TAZ (Yorkie), and TEAD1/2/3/4 (Scalloped) (Halder and Johnson, 2011; Pan, 2007; Dong et al., 2007; Saucedo and Edgar, 2007). When Hippo signaling is active, YAP1/TAZ is phosphorylated by LATS1/2 and sequestered by 14-3-3 proteins in cytoplasm. When Hippo signaling is absent, unphosphorylated YAP1/TAZ enters the nucleus and increases transcriptional activation of genes involved in cell proliferation and survival. The indispensability of the Hippo pathway in restricting cell growth and proliferation has prompted speculation that many members of the pathway might be involved in tumorigenesis. To see the effect of YAP1 and TAZ in HCC cell, we generated gene expression profile.
Project description:The Hippo pathway plays an important role in regulating tissue homeostasis, and its effectors YAP and TAZ are responsible for mediating the vast majority of its physiological functions. Although YAP and TAZ are thought to be largely redundant and similarly regulated by Hippo signaling, they have developmental, structural, and physiological differences which suggest there may be differences in their regulation and downstream functions. To better understand the functions of YAP and TAZ in the Hippo pathway, we generated knockout cells and evaluated them in response to many conditions and stimuli. Here, we used RNA-seq to identify and compare differences in the transcriptional profiles between the YAP and TAZ.
Project description:To investigate the effect of TEAD2 acetylation in transcriptional regulation through profiling three groups of cells with different TEAD2 acetylaiton state.
Project description:Mouse embryonic stem cells (mESCs) cultured in 2i (MEK and GSK3 kinase inhibitor)/LIF and serum/LIF that we called 2i-ESCs and serum-ESCs represent ground and confused pluripotent states, respectively. However, the transcription factors that regulate ground pluripotency through chromatin-associated characteristics are not yet fully understood. By mapping chromatin accessibility and transcription factor regulatory networks during the interconversion of 2i-ESCs and serum-ESCs, we have identified TEAD2 as highly enriched in 2i-specific peaks. While Tead2 knockout did not affect the pluripotency or differentiation ability of either 2i-ESCs or serum-ESCs, it did prevent the establishment of the 2i-specific state and the exit from the serum-specific state. TEAD2 binds to active regions in 2i-specific genes and activates their expression by regulating enhancer-promoter (EP) interactions during serum-to-2i transition. Remarkably, TEAD2-mediated EP interactions were independent of chromatin architecture proteins YY1 and CTCF, but instead appear to be facilitated by TEAD2 homodimer formation.