Project description:We have demonstrated that the oncogenic activation of B-RAF (using a truncated delta-BRAF-ER version inducible with tamoxifen) in the melan-a melanocyte cell line triggers the activation of Zeb1 and Twist1 at the expanse of Zeb2 and Snail2. Enforced maintenance of Zeb2 or Snail2 expression reduces the B-RAF oncogenic potential while ectopic expression of Zeb1 or Twist1 cooperates with B-RAF in melan-a cell transformation. To get an insight into the properties of these embryonic transcription factors, gene expression profiles of melan-a-derived cell lines either expressing a non-activated B-RAF (- tamoxifen) or an activated BRAF (+ tamoxifen) alone or in combination with Snail2, Zeb2, Twist1 or Zeb1 have been established. Melan-a cells were transduced with an activated version of BRAF(delta-BRAF-ER, inducible with tamoxifen) alone or in combination with SNAIL2, ZEB2, ZEB1 or TWIST1. Gene expression profiles before or following BRAF activation (alone or in combination with the embryonic transcription factors) were determined. Ectopic expression of SNAIL2, ZEB2, ZEB1 or TWIST1 on BRAF-target genes in the murine melanocytic melan-a cell line.
Project description:We have demonstrated that the oncogenic activation of B-RAF (using a truncated delta-BRAF-ER version inducible with tamoxifen) in the melan-a melanocyte cell line triggers the activation of Zeb1 and Twist1 at the expanse of Zeb2 and Snail2. Enforced maintenance of Zeb2 or Snail2 expression reduces the B-RAF oncogenic potential while ectopic expression of Zeb1 or Twist1 cooperates with B-RAF in melan-a cell transformation. To get an insight into the properties of these embryonic transcription factors, gene expression profiles of melan-a-derived cell lines either expressing a non-activated B-RAF (- tamoxifen) or an activated BRAF (+ tamoxifen) alone or in combination with Snail2, Zeb2, Twist1 or Zeb1 have been established.
Project description:The newly identified claudin-low subtype of cancer is believed to represent the most primitive breast malignancies, having arisen from transformation of an early epithelial precursor with inherent stemness properties and metaplastic features. Challenging this hypothesis, we show both in vitro and in vivo that transcription factors inducing epithelial-mesenchymal transition can drive the development of claudin-low tumors from differentiated mammary epithelial cells, by playing a dual role in cell transformation and dedifferentiation. Human mammary epithelial cells (HMEC) were sequentially immortalized by hTert (HMEC-hTert), transduced with Twist1 or Zeb2 or Zeb1 and then with H-RasG12V. The gene expression profiles of the resulting HMEC-hTert-Twist1+Ras, HMEC-hTert-Zeb1+Ras and HMEC-hTert-Zeb2+Ras cell lines were defined. HMEC-hTert-Twist1+Ras and HMEC-hTert-Zeb2+Ras cell lines were additionally cultured in presence of TGFM-CM-^C? and their gene expression profiles were determined. The parental HMEC-hTert, the luminal MCF7 and the basal B MDMB157cell lines were used as controls.
Project description:Throughout most of pregnancy, uterine quiescence is maintained by increased progesterone receptor (PR) transcriptional activity, while spontaneous labor is initiated/facilitated by a concerted series of biochemical events that activate inflammatory pathways and negatively impact PR function. In this study, we uncovered a new regulatory pathway whereby miRNAs serve as hormonally-modulated and conserved mediators of contraction-associated genes in the pregnant uterus from mouse to human. Using miRNA and gene expression microarray analyses of uterine tissues, we identified a conserved family of miRNAs, the miR-200 family, that is highly induced at term in both mice and humans, as well as two coordinately downregulated targets, zinc finger E-box binding homeobox proteins, ZEB1 and ZEB2, which act as transcriptional repressors. We also observed upregulation of the miR-200 family and downregulation of ZEB1 and ZEB2 in two different mouse models of preterm labor. We further demonstrated that ZEB1 is directly upregulated by the action of P4/PR at the ZEB1 promoter. Excitingly, we observed that ZEB1 and ZEB2 inhibit expression of the contraction- associated genes, oxytocin receptor and connexin-43 and block oxytocin-induced contractility in human myometrial cells. Together, these findings implicate the miR-200 family and their targets ZEB1 and ZEB2 as novel progesterone/PR- mediated regulators of uterine quiescence and contractility during pregnancy and labor, and shed new light on the molecular mechanisms involved in preterm birth. RNA was purified from mouse myometrium (miRNeasy kit, Qiagen). miRNA microarray was performed (LC Sciences) on 18 biological replicates of murine myometrium at 15.5 dpc and an equal number of replicates at 18.5 dpc. Gene expression microarray assays were performed (UT Southwestern Medical Center) on the same 36 samples as detailed further in SI Materials and Methods.
Project description:EMT was induced using stable overexpression of 1 of 4 EMT transcription factors (FOXQ1, TWIST1, ZEB2, and SNAI1) in the HMLE cell line. HMLE cells with ectopic LACZ expression were used as control cells.
Project description:Systemic lupus erythematosus (SLE) damages multiple organs by producing various autoantibodies. Insufficient interleukin-2 (IL-2) production causes decreased regulatory T cells and permits expansion of autoreactive T cells in the development of SLE. We here show that decreased miR-200a-3p causes IL-2 hypoproduction through directly recruiting ZEB1 or ZEB2 and CtBP2 (ZEB1/ZEB2-CtBP2) complex in SLE T cells. First, we performed RNA sequencing with Illumina Hiseq to obtain the candidate miRNAs and mRNAs involved in the pathogenesis of SLE. We found that miR-200a-3p was significantly downregulated, while its putative targets, ZEB2 and CtBP2 were upregulated in CD4+ T cells in MRL/lpr lupus model mice compared with those of C57BL/6J control mice. ZEB1 and ZEB2 compose ZEB family and suppress various genes including IL-2 by recruiting CtBP2. IL-2 plays a critical role in immune tolerance and IL-2 defect has been recognized in SLE pathogenesis. Therefore, we hypothesized that decreased miR-200a-3p cause IL-2 defect through ZEB1/ZEB2-CtBP2 complex in SLE CD4+T cells. Overexpression of miR-200a-3p induced IL-2 production though downregulating ZEB1, ZEB2 and CtBP2 in EL4 cell lines. We further revealed that miR-200a-3p promote IL-2 expression by reducing the bindings of suppressive ZEB1/ZEB2-CtBP2 complex on NRE-A of IL-2 promoter in SLE murine T cells. Interestingly, ZEB1/ZEB2-CtBP2 complex on NRE-A (a negative regulatory element) were significantly upregulated after phorbol-12-myristate-13-acetate and ionomycin (PMA/Iono) stimulation in lupus T cells. Our findings provide a new insight for the epigenetic regulation of IL-2 defect in SLE.
Project description:Purpose: Characterize the gene expression profile of gastrocnemius muscle in wild type, ZEB1 and ZEB2 knock out mice subjected to 36 hours of fasting Methods: RNA sequencing of RNA from total gastrocnemius muscle after 36h of fasting from the three genotypes used in this study: ZEB1-control, ZEB1-KO, ZEB2-control, ZEB2-KO. Males and females were used from the four genotype (ZEB1flx/flx, ZEB1flx/flx;HSACre, ZEB2flx/flx, ZEB2flx/flx;HSACre). Results: Knockout of ZEB1 or ZEB2 results in differential gene expression in atrophic gastrocnemius muscle Conclusions: Comparison of wild type, ZEB1 and ZEB2 KO muscles displayed differential gene expression profiles after fasting
Project description:Throughout most of pregnancy, uterine quiescence is maintained by increased progesterone receptor (PR) transcriptional activity, while spontaneous labor is initiated/facilitated by a concerted series of biochemical events that activate inflammatory pathways and negatively impact PR function. In this study, we uncovered a new regulatory pathway whereby miRNAs serve as hormonally-modulated and conserved mediators of contraction-associated genes in the pregnant uterus from mouse to human. Using miRNA and gene expression microarray analyses of uterine tissues, we identified a conserved family of miRNAs, the miR-200 family, that is highly induced at term in both mice and humans, as well as two coordinately downregulated targets, zinc finger E-box binding homeobox proteins, ZEB1 and ZEB2, which act as transcriptional repressors. We also observed upregulation of the miR-200 family and downregulation of ZEB1 and ZEB2 in two different mouse models of preterm labor. We further demonstrated that ZEB1 is directly upregulated by the action of P4/PR at the ZEB1 promoter. Excitingly, we observed that ZEB1 and ZEB2 inhibit expression of the contraction- associated genes, oxytocin receptor and connexin-43 and block oxytocin-induced contractility in human myometrial cells. Together, these findings implicate the miR-200 family and their targets ZEB1 and ZEB2 as novel progesterone/PR- mediated regulators of uterine quiescence and contractility during pregnancy and labor, and shed new light on the molecular mechanisms involved in preterm birth.
Project description:Purpose: Characterize the gene expression profile of knocked-down ZEB1 and ZEB2 H9 cells during myogenic differentiation through RNA sequencing Methods: RNA sequencing of RNA from cell cultures treated for 2 days with CHIR from the three genotypes used in this study: H9shCTL, H9shZEB1 and H9shZEB2 Results: Knock-down of ZEB1 and ZEB2 in H9 cells results in differential gene expression upon differentiation. Conclusions: Compairson of knocked-down ZEB1 and ZEB2 H9 cells display differences in gene expression at day 2 of the differentiation protocol.
Project description:This SuperSeries is composed of the SubSeries listed below. Zinc finger E-box binding protein 1 (ZEB1) and ZEB2 induce epithelial-mesenchymal transition (EMT) and cancer progression. However, little is known about global picture of transcriptional regulation by ZEB1 and ZEB2. Here we identified an inflammatory phenotype regulated by ZEB1 using chromatin immunoprecipitation-sequencing (ChIP-seq) and RNA-sequencing (RNA-seq) in basal type breast cancer cells, followed by gene set enrichment analysis (GSEA) of ZEB1-bound genes.