Project description:GATA6 is a zinc finger transcription factor that is required for the proliferation, development and specific gene regulation in the gastrointestinal tract. We have recently reported that GATA6-mediated induction of the intestinal stem cell marker LGR5 is required for the tumorigenicity of colon cancer cells. However, knockdown of LGR5, unlike GATA6, does not affect the proliferation of these cells under adherent conditions. Here we show that REG4, a member of the regenerating islet-derived (REG) family, is a target of GATA6. We further demonstrate that REG4 is downregulated by overexpression of miR-363, which suppresses GATA6 expression. Moreover, we show that GATA6-mediated activation of REG4 causes an acceleration of the growth of colon cancer cells under adherent conditions. These results suggest that GATA6 simultaneously activates the transcription of genes required for growth (REG4) and clonogenicity (LGR5), and the miR-363-GATA6-REG4/LGR5 pathway is critical for colorectal tumorigenesis. HT29 cells were transfected with a siRNA targeting GATA6.
Project description:GATA6 is a zinc finger transcription factor that is required for the proliferation, development and specific gene regulation in the gastrointestinal tract. We have recently reported that GATA6-mediated induction of the intestinal stem cell marker LGR5 is required for the tumorigenicity of colon cancer cells. However, knockdown of LGR5, unlike GATA6, does not affect the proliferation of these cells under adherent conditions. Here we show that REG4, a member of the regenerating islet-derived (REG) family, is a target of GATA6. We further demonstrate that REG4 is downregulated by overexpression of miR-363, which suppresses GATA6 expression. Moreover, we show that GATA6-mediated activation of REG4 causes an acceleration of the growth of colon cancer cells under adherent conditions. These results suggest that GATA6 simultaneously activates the transcription of genes required for growth (REG4) and clonogenicity (LGR5), and the miR-363-GATA6-REG4/LGR5 pathway is critical for colorectal tumorigenesis.
Project description:GATA6 is a zinc finger transcription factor that is required for the proliferation, development and specific gene regulation in the gastrointestinal tract. We have recently reported that GATA6-mediated induction of the intestinal stem cell marker LGR5 is required for the tumorigenicity of colon cancer cells. However, knockdown of LGR5, unlike GATA6, does not affect the proliferation of these cells under adherent conditions. Here we show that REG4, a member of the regenerating islet-derived (REG) family, is a target of GATA6. We further demonstrate that REG4 is downregulated by overexpression of miR-363, which suppresses GATA6 expression. Moreover, we show that GATA6-mediated activation of REG4 causes an acceleration of the growth of colon cancer cells under adherent conditions. These results suggest that GATA6 simultaneously activates the transcription of genes required for growth (REG4) and clonogenicity (LGR5), and the miR-363-GATA6-REG4/LGR5 pathway is critical for colorectal tumorigenesis. HT29 cells were transfected with a siRNA targeting LGR5.
Project description:GATA6 is a zinc finger transcription factor that is required for the proliferation, development and specific gene regulation in the gastrointestinal tract. We have recently reported that GATA6-mediated induction of the intestinal stem cell marker LGR5 is required for the tumorigenicity of colon cancer cells. However, knockdown of LGR5, unlike GATA6, does not affect the proliferation of these cells under adherent conditions. Here we show that REG4, a member of the regenerating islet-derived (REG) family, is a target of GATA6. We further demonstrate that REG4 is downregulated by overexpression of miR-363, which suppresses GATA6 expression. Moreover, we show that GATA6-mediated activation of REG4 causes an acceleration of the growth of colon cancer cells under adherent conditions. These results suggest that GATA6 simultaneously activates the transcription of genes required for growth (REG4) and clonogenicity (LGR5), and the miR-363-GATA6-REG4/LGR5 pathway is critical for colorectal tumorigenesis. HT29 cells were transfected with a siRNA targeting REG4.
Project description:Transcriptome analysis has uncovered a series of long noncoding RNAs (lncRNAs) transcribed during cell differentiation. Here, we uncovered lncRNA GATA6-AS1 is a functional lncRNA in definitive endoderm (DE) differentiation. We found GATA6-AS1 positively regulated the expression of endoderm key factor GATA6, which was different from previous reports in other biological contexts. Further investigation showed GATA6-AS1 interacted with SMAD2/3 and recruited SMAD2/3 to the promoter region of the GATA6 gene locus. In addition, overexpression of GATA6 was able to rescue the defect of DE differentiation due to the absence of GATA6-AS1, suggesting GATA6 was the functional target of GATA6-AS1 during endoderm differentiation. Ultimately, our study uncovers GATA6-AS1 is necessary for DE and pancreas differentiation, and reveals the detailed regulation mechanism between GATA6-AS1 and DE differentiation.
Project description:By studying a mouse model, as well as human tumors samples and cell lines, we have revealed a tumor suppressive role for Gata6 in the pathogenesis of pancreatic ductal adenocarcinoma (PDAC). In order to understand the mechanism underlying such tumor suppressive function, we analyzed the genome-wide DNA-binding of GATA6 in a human PDAC cell line (PaTu8988S). GATA6 is found to bind the promoter of genes involved in the epithelial differentiation programme, as well as of genes involved in the mesenchymal programme. With this we describe a novel GATA6-dependent mechanism of regulation of EMT. Examination of GATA6 binding to the DNA in a human PDAC cell line
Project description:Genome-wide cDNA array from HT29,HT29-shROR,HT29-Mock, AGS, AGS-shROR, AGS-Mock cells We used microarrays to detail the global programme of gene expression and identified significantly changed genes after ROR depletion.
Project description:In adult K14Î?NLef1 mouse, the overexpression of â??NLef1, a Ã?-catenin dominat negative, in basal keratinocytes leads to the conversion of hair follicles into multilayered epithelial cysts and ectopic sebaceous gland. â??NLef1 transcriptional activity led to Gata6 overexpression in the pilosebaceous unit in transgenic mice. To uncover direct target genes of Gata6 we performed ChIP-Seq experiments in primary mouse keratinocytes. Examination of Gata6 genomic targets in mouse primary keratinocytes
Project description:We describe the genome-wide DNA-binding of GATA6 in a human CRC cell line (LS174T). GATA6 is found to bind the promoter of genes involved in the maintenance of intestinal stem cells, including genes of the Wnt and TGFbeta/BMP pathways. With this we describe a novel GATA6-dependent mechanism of stem cell maintenance in colorectal tumors. Examination of GATA6 binding and H3K4me1, H3K4me3 and H3K27ac levels in a human CRC cell line by Chromatin immunoprecipitation followed by deep sequencing.
Project description:To characterize gene expression in Gata6 positive epidermal cells we analyzed a Gata6 reporter mouse in which the endogenous Gata6 promoter drives expression of mTomato. We performed flow cytometry followed by transcriptome analysis. We compared four subpopulations of telogen epidermal cells: Gata6+/Itga6+ cells, Gata6+/itga6- cells, CD34+/Itga6+ cells (which are Gata6-) and all remaining Itga6+ cells (Gata6-/CD34-). The RNA was isolated from age and sex matched mice.