ABSTRACT: Grainyhead genes are involved in wound healing and developmental neural tube closure. In light of the high degree of similarity between the epithelial-mesenchymal transitions (EMTs) occurring in wound healing processes and the cancer stem cell-like compartment of tumors, including TGF-β-dependence, we investigated the role of a Grainyhead gene (GRHL2) in oncogenic EMT. Grainyhead was specifically down-regulated in the claudin-low subclass of mammary tumors and in the basal-B subclass of breast cancer cell lines. Functionally, GRHL2 suppressed TGF-β-induced, Twist-induced or spontaneous EMT, enhanced anoikis-sensitivity, and suppressed mammosphere generation in mammary epithelial cells. These effects were mediated, in part, by its suppression of ZEB1 expression, through direct repression of the ZEB1 promoter. GRHL2 also inhibited Smad-mediated transcription, and up-regulated mir200b/c as well as the TGF-β receptor antagonist, BMP2. The expression of GRHL2 in the breast cancer cell line MDA-MB-231 triggered a mesenchymal-to-epithelial transition and sensitized the cells to anoikis. These results indicate that GRHL2 is a suppressor of the oncogenic EMT. 3 biologic replicates for each cell line. Comparison of HMLE+Twist-ER cells expressing GRHL2/pMIG vs. HMLE+Twist-ER cells expressing empty pMIG.
Project description:Grainyhead genes are involved in wound healing and developmental neural tube closure. In light of the high degree of similarity between the epithelial-mesenchymal transitions (EMTs) occurring in wound healing processes and the cancer stem cell-like compartment of tumors, including TGF-β-dependence, we investigated the role of a Grainyhead gene (GRHL2) in oncogenic EMT. Grainyhead was specifically down-regulated in the claudin-low subclass of mammary tumors and in the basal-B subclass of breast cancer cell lines. Functionally, GRHL2 suppressed TGF-β-induced, Twist-induced or spontaneous EMT, enhanced anoikis-sensitivity, and suppressed mammosphere generation in mammary epithelial cells. These effects were mediated, in part, by its suppression of ZEB1 expression, through direct repression of the ZEB1 promoter. GRHL2 also inhibited Smad-mediated transcription, and up-regulated mir200b/c as well as the TGF-β receptor antagonist, BMP2. The expression of GRHL2 in the breast cancer cell line MDA-MB-231 triggered a mesenchymal-to-epithelial transition and sensitized the cells to anoikis. These results indicate that GRHL2 is a suppressor of the oncogenic EMT.
Project description:Twist is a key EMT inducer, expression of Twist will induce EMT in HMLE and breast tumor T47D cells By expressing Twist in HMLE and T47D cells, which lack the expression of Twist, will identify the genes regulated by Twist
Project description:Twist is a key EMT inducer, expression of Twist will induce EMT in HMLE and breast tumor T47D cells By expressing Twist in HMLE and T47D cells, which lack the expression of Twist, will identify the genes regulated by Twist Expressing Twist in HMLE and T47D cells, stable clones were selected and treated with BET inhibitor JQ1 and RNA were prepared for microarray analysis
Project description:Snail and Twist are two EMT inducer, expression of Snail or Twist will induce EMT in HMLE and MCF10A cells. By introducing Snail or Twist in HMLE and MCF10A cells, which lack the expression of these two proteins, will identify the genes are induced during EMT. We used microarray analysis to compare the gene expression profiles between the mammamry epithleial cells and the cells undergone EMT.
Project description:We quantified protein expression changes between epithelial and mesechymal stages in immortalized human mammary epithelial cells (HMLE). Epithelial–mesenchymal transition is induced by expressing an EMT-TF, Twist.
Project description:Epithelial-to-mesenchymal transition (EMT) gives rise to cells with properties similar to cancer stem cells (CSCs) that drive tumor metastasis. Recently, a screening of a large compound library on a breast EMT model has identified salinomycin, a K+/H+ ionophore, as a highly selective drug towards CSCs. We used the same EMT model to show that salinomycin targets Golgi apparatus. We have performed RNA-seq analysis on HMLE-Twist and HMLE-pBp cells (EMT and non-EMT) that were either mock treated or treated for 24h with micro molar concentration (0.2uM) of salinomycin. Salinomycin induced expression of genes enriched by known ER and Golgi stressors.
Project description:Epithelial ovarian cancer (EOC) is clinically heterogeneous, comprising different histological and biological subtypes. Multiple studies have implicated epithelial-mesenchymal transition (EMT), a biological process by which polarized epithelial cells convert into a mesenchymal phenotype, to contribute significantly to this molecular heterogeneity of EOC. From gene expression analyses of a collection of EMT-characterized EOC cell lines, we found that the expression of the transcription factor Grainyhead-like 2 (GRHL2) correlates with E-cadherin expression and the epithelial phenotype. EOC tumors with lower levels of GRHL2 are associated with the Mes (mesenchymal) molecular subtype and show poorer overall survival in patients. Here, we demonstrate that shRNA-mediated knockdown of GRHL2 in EOC cells with an epithelial phenotype resulted in EMT changes, with increased cell migration, invasion and motility. By ChIP-sequencing and gene expression microarray, we identified a variety of target genes regulated by GRHL2, including protein-coding and non-coding genes. Our data suggest that GRHL2 maintains the epithelial phenotype of EOC cells through the regulatory networks of miR-200b/a, ZEB1 and E-cadherin. These findings support GRHL2 as a crucial player in the molecular heterogeneity of EOC. 7 samples were analyzed (shNon control in duplicates; shGRHL2 #10 in duplicates, shGRHL2 #12 in triplicates)
Project description:The Grainyhead family of transcription factors controls morphogenesis and differentiation of epithelial cell layers in multicellular organisms by regulating cell junction- and proliferation-related genes. Grainyhead-like 2 (Grhl2) is expressed in developing mouse lung epithelium and is required for normal lung organogenesis. The specific epithelial cells expressing Grhl2 and the genes regulated by Grhl2 in normal lungs are mostly unknown. In these studies, we identified the NK2 homeobox 1 transcription factor (Nkx2-1) as a direct transcriptional target of Grhl2. By binding and transcriptional assays, and by confocal microscopy we showed that these two transcription factors form a positive feed-back loop in vivo and in cell lines, and are co-expressed in lung bronchiolar and alveolar type II cells. The morphological changes observed in flattening lung alveolar type II cells in culture are associated with down-regulation of Grhl2 and Nkx2-1. Reduction of Grhl2 in lung epithelial cell lines results in lower expression levels of Nkx2-1 and of known Grhl2 target genes. By microarray analysis we identified that in addition to Cadherin1 and Claudin4, Grhl2 regulates other cell interaction genes such as semaphorins and their receptors, which also play a functional role in developing lung epithelium. Impaired collective cell migration observed in Grhl2 knockdown cell monolayers is associated with reduced expression of these genes and may contribute to the altered epithelial phenotype reported in Grhl2 mutant mice. Thus, Grhl2 functions at the nexus of a novel regulatory network, connecting lung epithelial cell identity, migration and cell-cell interactions. To identify genes regulated by GRHL2 in lung epithelial cells, we performed cDNA microarray analyses in MLE15 cells transduced with Grhl2-shRNA and compared to a non-silencing control. Independent transductions of MLE15 cells using Grhl2-shRNA (n=3) and a non-silencing control (n=2) were analyzed.
Project description:Ovarian cancer (OC) cells exhibit varying extents of epithelial/mesenchymal phenotype, forming an EMT spectrum based on their EMT scores. Combining 450K DNA methylation array, ChIP-sequencing of five histone H3 marks (H3K4me1, H3K4me3, H3K27Ac, H3K27me3 and H3K9me3) and transcriptomic analyses, we examined the genome-wide epigenetic profiles of OC cell lines with progressive EMT phenotypes, including a knockdown model of EMT suppressor Grainyhead-like 2 (GRHL2) which showed intermediate state transition. We identified differentially methylated CpG sites (DMCs) associated with EMT genes, found mainly at the promoters of epithelial genes including CDH1, GRHL2 and genes with GRHL2 binding sites. This prompted us to further study the epigenetic role of GRHL2. GRHL2-knockdown resulted in CpG methylation gain at GRHL2 binding sites and at DMCs associated with epithelial genes. Importantly, the changes of histone modifications occurred in GRHL2-knockdown cells are also more prominent among epithelial genes and at GRHL2 binding sites—reduction in permissive marks H3K4me3 and H3K27ac; elevated repressive mark H3K27me3—similar to the transitions observed in a four-cell-line model representing the EMT spectrum. We tested the effects of GRHL2 overexpression in conjunction with epigenetic drugs 5-azacitidine, GSK126 and mocetinostat, all of which exerted MET effects to different extents, depending on the existing cell state. Overall, GRHL2 is required for the epigenetic and chromatin remodeling of epithelial genes during EMT/MET that control intermediate phenotype switching.