Project description:Our group is interested in epithelial-to-mesenchymal transition (EMT), in particular, TGF-beta induced EMT. TGF-beta signalling has been shown to be an important factor in the induction of EMT and it has been demonstrated that adding TGF-beta to epithelial cells in culture is a convenient way to study the process of EMT. In response to TGF-beta, Smad2 and 3 are activated, and form complexes with Smad4, which then regulate transcription of target genes through interactions with other DNA binding transcription factors. In the induction of EMT, the activated Smads mediate transcriptional regulation through three families of transcription factors, resulting in repression of epithelial marker gene expression and activation of mesenchymal gene expression (Xu J, et al. 2009) <br></br> Also investigated in this study is the role of H2A.Z in EMT. H2A.Z is an evolutionary conserved and a metazoan essential histone variant of the H2A class. Mice deficient in H2A.Z die during early development but the reason for this is unknown (Faast et al. 2001). Previously, our laboratory showed that the loss of H2A.Z in Xenpous laevis impaired cell movement required for the formation of the mesoderm and neural crest (Ridgway et al. 2004). Given that mesoderm formation is critically dependent upon EMT, we therefore wondered whether H2A.Z might be a chromatin regulator of EMT. We transfected MDCK cells with a lentiviral vector to express a construct encoding an shRNA targeting canine H2A.Z as we wanted to test the hypothesis that H2A.Z is involved in the maintenance of cellular identity and that its loss might trigger de-differentiation. <br></br> In order to investigate changes in histone variant H2A.Z occupancy associated with TGF-beta induced epithelial-to-mesenchymal transition (EMT) we performed H2A.Z ChIP-Seq in untreated and TGFb-treated MDCK cells. The MDCK cell line has been extensively used as a model system for EMT because they convert fully from the epithelial to the mesenchymal state in response to TGF-beta. <br></br>Please note that RNA-seq data generated in conjunction to this ChIP-seq data set were also deposited at ArrayExpress under accession number E-MTAB-5628 ( https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-5628 ).
Project description:Our group is interested in epithelial-to-mesenchymal transition (EMT), in particular, TGF-beta induced EMT. TGF-beta signalling has been shown to be an important factor in the induction of EMT and it has been demonstrated that adding TGF-beta to epithelial cells in culture is a convenient way to study the process of EMT. âIn response to TGF-beta, Smad2 and 3 are activated, and form complexes with Smad4, which then regulate transcription of target genes through interactions with other DNA binding transcription factors. In the induction of EMT, the activated Smads mediate transcriptional regulation through three families of transcription factors, resulting in repression of epithelial marker gene expression and activation of mesenchymal gene expressionâ (Xu J, et al. 2009) <br></br> Also investigated in this study is the role of H2A.Z in EMT. H2A.Z is an evolutionary conserved and a metazoan essential histone variant of the H2A class. Mice deficient in H2A.Z die during early development but the reason for this is unknown (Faast et al. 2001). Previously, our laboratory showed that the loss of H2A.Z in Xenpous laevis impaired cell movement required for the formation of the mesoderm and neural crest (Ridgway et al. 2004). Given that mesoderm formation is critically dependent upon EMT, we therefore wondered whether H2A.Z might be a chromatin regulator of EMT. We transfected MDCK cells with a lentiviral vector to express a construct encoding an shRNA targeting canine H2A.Z as we wanted to test the hypothesis that H2A.Z is involved in the maintenance of cellular identity and that its loss might trigger de-differentiation. <br></br> In order to investigate changes in gene expression associated with TGF-beta induced epithelial-to-mesenchymal transition (EMT) we performed paired end RNA-Seq of poly-A selected mRNA in untreated and TGFb-treated MDCK cells. The MDCK cell line has been extensively used as a model system for EMT because they convert fully from the epithelial to the mesenchymal state in response to TGF-beta. Gene expression profiles were also generated from MDCK cells in which H2A.Z was knocked down using shRNA.<br></br>Please note that ChIP-seq data generated in conjunction to this RNA-seq data set were also deposited at ArrayExpress under accession number E-MTAB-5637 ( https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-5637 ).
Project description:Epithelial-to-mesenchymal transitions (EMT) play prominent roles during development, regeneration and tumor progression. EMTs are triggered by TGF-β, RAS and other signals that cooperatively induce the expression of master EMT transcription factors such as SNAIL. Here, we elucidate how the TGF-β and RAS pathways jointly trigger EMTs and tie them to broader developmental programs. We identify RAS response element binding protein 1 (RREB1) as a critical partner of TGF-β-activated SMAD transcription factors in driving SNAIL expression and EMT program in mammary gland epithelial cells.
Project description:TGF-β is a major tumor suppressor in gastrointestinal (GI) and squamous carcinomas, which exhibit frequent genetic inactivation of Smad4, a key TGF-β signaling component. Apoptosis is implicated as an important mediator of the tumor suppressive function of TGF-β, although this process remains poorly understood. To address this long-standing question, we dissected the tumor suppressive action of TGF-β in naïve pancreatic ductal adenocarcinoma (PDA) cells. Here we show that TGF-β/Smad4 signaling triggers an EMT in Kras-mutant pancreatic progenitor cells but turns this process into a trigger of apoptosis by converting the progenitor cell transcription factor Sox4 from an enforcer of epithelial progenitor identity into an activator of apoptosis. This occurs as a result of the EMT-linked repression of the endodermal master regulator Klf5, which cooperates with Sox4 to promote epithelial progenitor identity, and loss of which unmasks a latent apoptotic transcriptional program driven by Sox4. By losing Smad4, Kras-mutant PDA cells avoid this fate and instead use Sox4 as a TGF-β-dependent enforcer of the epithelial progenitor cell state.
Project description:Epithelial-to-mesenchymal transitions (EMT) play prominent roles during development, regeneration and tumor progression. EMTs are triggered by TGF-β, RAS and other signals that cooperatively induce the expression of master EMT transcription factors such as SNAIL. Here, we elucidate how the TGF-β and RAS pathways jointly trigger EMTs and tie them to broader developmental programs. We identify RAS response element binding protein 1 (RREB1) as a critical partner of TGF-β-activated SMAD transcription factors in driving SNAIL expression in pancreatic pre-malignant epithelial cells, lung adenocarcinoma cells, and embryonic stem cells. Moreover, SMADs and RREB1 also drive EMT-associated fibrogenic programs in epithelial cells and mesendoderm differentiation in pluripotent embryonic cells. These findings illuminate the orchestration of EMT associated programs in gastrulation, fibrosis, and cancer.
Project description:The goal of this study is to characterize time course gene expression profiles during TGF-beta induced EMT. In particular, we aim to identify and characterize master transcription factors regulate the transition into partial-EMT state. A time series mRNA profile in A549 cells is generated from TGF-beta induced EMT samples during 0h,6h,12h,24h,36h,48h,72h and 96h by deep sequencing, in duplicate, using Illumina HiSeq 2500
Project description:Extracellular matrix (ECM) tumorigenic alterations resulting in high matrix deposition and stiffening are hallmarks of adenocarcinomas and are collectively defined as desmoplasia. Here, we thoroughly analysed primary prostate cancer tissues obtained from numerous patients undergoing radical prostatectomy to highlight reproducible structural changes in the ECM leading to the loss of the glandular architecture. Starting from patient cells, we established prostate cancer tumoroids (PCTs) and demonstrated they require TGF-β signalling pathway activity to preserve phenotypical and structural similarities with the tissue of origin. By modulating TGF-β signalling pathway in PCTs, we unveiled its role in ECM accumulation and remodelling in prostate cancer. We also found that TGF-β-induced ECM remodelling is responsible for the initiation of prostate cell epithelial-to-mesenchymal transition (EMT) and the acquisition of a migratory, invasive phenotype. Our findings highlight the cooperative role of TGF-β signalling and ECM desmoplasia in prompting prostate cell EMT and promoting tumour progression and dissemination.
Project description:To gain more information about EMT induced by oncogenic Ras in MDCK cells, we performed RNA-seq of MDCK and MDCK-Ras cells and compared their genome-wide gene expression profiles.