Project description:Epithelial stem cells self-renew while maintaining multipotency, but the dependence of stem cell properties on maintenance of the epithelial phenotype is unclear. We previously showed that trophoblast stem (TS) cells lacking the protein kinase MAP3K4 maintain properties of both stemness and epithelial-mesenchymal transition (EMT). Here, we show that MAP3K4 controls the activity of the histone acetyltransferase CBP, and that acetylation of histone H2B by CBP is specifically required to maintain the epithelial phenotype. Combined loss of MAP3K4/CBP activity represses expression of epithelial genes and causes TS cells to undergo EMT while maintaining their self-renewal and multipotency properties. The expression profile of MAP3K4 deficient TS cells defines an H2B acetylation regulated gene signature that closely overlaps with that of human breast cancer cells. Taken together, our data define an epigenetic switch that maintains the epithelial phenotype in TS cells and reveal previously unrecognized genes potentially contributing to breast cancer. Three separate trophoblast stem (TS) cell conditions were compared to define the gene expression changes that occur with the induction of epithelial-mesenchymal transition (EMT) in TS cells. These conditions were TS cells differentiated for 4 days (T^Diff), TS cells differentiated for 4-days and isolated following invasion through Matrigel (T^Inv), and TS cells with an inactive MAP3K4 (TS^KI4). All conditions were normalized to wild-type control TS cells (TS^WT). T^Diff and T^Inv were analyzed in triplicate. TS^KI4 was analyzed in duplicate in two independent biological replicates.
Project description:Epithelial stem cells self-renew while maintaining multipotency, but the dependence of stem cell properties on maintenance of the epithelial phenotype is unclear. We previously showed that trophoblast stem (TS) cells lacking the protein kinase MAP3K4 maintain properties of both stemness and epithelial-mesenchymal transition (EMT). Here, we show that MAP3K4 controls the activity of the histone acetyltransferase CBP, and that acetylation of histone H2B by CBP is specifically required to maintain the epithelial phenotype. Combined loss of MAP3K4/CBP activity represses expression of epithelial genes and causes TS cells to undergo EMT while maintaining their self-renewal and multipotency properties. The expression profile of MAP3K4 deficient TS cells defines an H2B acetylation regulated gene signature that closely overlaps with that of human breast cancer cells. Taken together, our data define an epigenetic switch that maintains the epithelial phenotype in TS cells and reveal previously unrecognized genes potentially contributing to breast cancer.
Project description:MAP3K4 is a serine/threonine kinase that regulates epithelial to mesenchymal transition (EMT). Trophoblast stem (TS) cells lacking MAP3K4 kinase activity (TSKI4 cells) are in an intermediate state of EMT, having reduced epithelial and increased mesenchymal marker expression. Reduced epithelial gene expression in TSKI4 cells was due to loss of H2BK5 promoter acetylation catalyzed by the histone acetyltransferase CBP. Herein, we show that MAP3K4 also regulates the ubiquitination and degradation of the deacetylase HDAC6. Due to the loss of MAP3K4 kinase activity, TSKI4 cells have elevated HDAC6 expression and activity. Knockdown of HDAC6 in TSKI4 cells restores epithelial features, defining HDAC6 as a key regulator of EMT controlled by MAP3K4. HDAC6 promotes EMT by directly deacetylating H2BK5 on promoters of tight junction genes claudin6 and occludin, inhibiting their expression. Thus, MAP3K4 is a master regulator that coordinates chromatin modifiers, CBP and HDAC6, to regulate the transition between epithelial and mesenchymal states.
Project description:MAP3K4 is a serine/threonine kinase that regulates epithelial to mesenchymal transition (EMT). Trophoblast stem (TS) cells lacking MAP3K4 kinase activity (TSKI4 cells) are in an intermediate state of EMT, having reduced epithelial and increased mesenchymal marker expression. Reduced epithelial gene expression in TSKI4 cells was due to loss of H2BK5 promoter acetylation catalyzed by the histone acetyltransferase CBP. Herein, we show that MAP3K4 also regulates the ubiquitination and degradation of the deacetylase HDAC6. Due to the loss of MAP3K4 kinase activity, TSKI4 cells have elevated HDAC6 expression and activity. Knockdown of HDAC6 in TSKI4 cells restores epithelial features, defining HDAC6 as a key regulator of EMT controlled by MAP3K4. HDAC6 promotes EMT by directly deacetylating H2BK5 on promoters of tight junction genes claudin6 and occludin, inhibiting their expression. Thus, MAP3K4 is a master regulator that coordinates chromatin modifiers, CBP and HDAC6, to regulate the transition between epithelial and mesenchymal states.
Project description:Trophoblast stem cells lack MAP3K4 activity (TSKI4 cells) switch from epithelial phenotype to intermediate phenotype. Loss of epithelial phenotype is due to the loss of CBP histone acetyltransferase activity and the gain of histone deacetylase HDAC6 expression and activity. In our work, we identify a small network of 183 genes whose expression is co-regulated by MAP3K4, CBP, and HDAC6. Further, we define the key role of one of these co-regulated genes, Rel, in inducing epithelial phenotype in intermediate TSKI4 cells. We used microarrays to compare gene expression betweeen mesenchymal TS cells with inactive MAP3K4 (TSKI4 cells) and epithelial TSKI4 cells re-expressing REL (TSKI4R cells)
Project description:Trophoblast stem cells lack MAP3K4 activity (TSKI4 cells) switch from epithelial phenotype to intermediate phenotype. Loss of epithelial phenotype is due to the loss of CBP histone acetyltransferase activity and the gain of histone deacetylase HDAC6 expression and activity. In our work, we identify a small network of 183 genes whose expression is co-regulated by MAP3K4, CBP, and HDAC6. Further, we define the key role of one of these co-regulated genes, Rel, in inducing epithelial phenotype in intermediate TSKI4 cells.
Project description:The present study is aimed at detecting and measuring mRNA levels of genes involved in epithelial to mesenchymal transition (EMT) in biological samples, i.e. in peripheral blood samples of colorectal cancer (CRC) patients and healthy controls, to determine the presence of disease, its progression and risk of recurrence.
Project description:This work details the first global mass spectrometric analysis of histone H2B variants as cells undergo arsenic-mediated epithelial to mesenchymal transition.
Project description:MAP3K4 Kinase Activity Controls Chromatin Remodelers for Transitions Between Epithelial and Mesenchymal Phenotypes in Trophoblast Stem Cells
Project description:Histone acetylation is important for the activation of gene transcription but little is known about its direct ‘read/write’ mechanisms. Here, we report cryo-electron microscopy structures in which a p300/CBP multidomain monomer recognizes histone H4 N-terminal tail (NT) acetylation (ac) in a nucleosome and acetylates non-H4 histone NTs within the same nucleosome. p300/CBP not only recognized H4NTac via the bromodomain pocket responsible for ‘reading’, but also interacted with the DNA minor grooves via the outside of that pocket. This directed the catalytic center of p300/CBP to one of the non-H4 histone NTs. The primary target that p300 ‘writes’ by ‘reading’ H4NTac was H2BNT, and H2BNTac promoted H2A-H2B dissociation from the nucleosome. We propose a model in which p300/CBP ‘replicates’ histone NT acetylation within the H3-H4 tetramer to inherit epigenetic storage, and ‘transcribes’ it from the H3-H4 tetramer to the H2B-H2A dimers to activate context-dependent gene transcription through local nucleosome destabilization.