Project description:The epithelial-mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induced mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reversed these changes; as did silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibited similar metastases levels, but the cells with re-expressed H2A.X exhibited substantially elevated levels. We surmise that H2A.X re-expression led to partial EMT reversal and increased robustness in the HCT116 cells, permitting them to both form tumors and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlated inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a novel regulator of EMT. 9 samples in total including 4 replicates of control shRNA and 5 replicates of shH2A.X.
Project description:The epithelial-mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induced mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reversed these changes; as did silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibited similar metastases levels, but the cells with re-expressed H2A.X exhibited substantially elevated levels. We surmise that H2A.X re-expression led to partial EMT reversal and increased robustness in the HCT116 cells, permitting them to both form tumors and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlated inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a novel regulator of EMT.
Project description:The epithelial-mesenchymal transition (EMT) is thought to be essential for cancer metastasis. While chromatin remodeling is involved in EMT, histone variants contribution in EMT remains poorly investigated. Recently, we showed that silencing or removal of the histone variant H2A.X induced mesenchymal-like characteristics, including activation of the EMT transcription factors, Slug and ZEB1, in human colon cancer cells. Here, we provide the evidence that H2A.X loss in human non-tumorigenic breast cell line MCF10A results in a robust EMT activation, as substantiated by a genome-wide expression analysis. Cells deficient for H2A.X exhibit enhanced migration and invasion, along with an activation of a set of mesenchymal genes and a concomitant repression of epithelial genes. In the breast model, the EMT-related transcription factor Twist1 cooperates with Slug to regulate EMT upon H2A.X loss. Of interest, H2A.X expression level tightly correlates with Twist1, and to a lesser extent with Slug in the panel of human breast cancer cell lines of the NCI-60 datasets. These new findings indicate that H2A.X is involved in the EMT processes in cells of different origins but pairing with transcription factors for EMT may be tissue specific.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
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:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs. One-condition experment, gene expression of 3A6
Project description:The NFkB subunit RELA is a master transcriptional regulator of the committed epithelial-mesenchymal transition in airway epithelial cells
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.