Project description:Epithelial cells possess remarkable plasticity, having the ability to become mesenchymal cells through alterations in adhesion and motility (epithelial-to-mesenchymal transition or EMT). Recent studies suggest that EMT endows differentiated epithelial cells with stem cell traits, posing the interesting question of how epithelial plasticity is properly restricted to ensure epithelial differentiation during tissue morphogenesis. Here we identify zinc-finger transcription factor Ovol2 as a key suppressor of EMT of mammary epithelial cells. Epithelia-specific deletion of Ovol2 completely arrests mammary ductal morphogenesis, and depletes epithelial stem/progenitor cell reservoirs. Further, Ovol2-deficient epithelial cells undergo EMT in vivo to become non-epithelial cell types, and that Ovol2 directly represses key EMT inducers such as Zeb1 and regulates stem/progenitor cell responsiveness to TGF-beta. We also provide evidence for a suppressive role of Ovol2 in breast cancer progression. Our findings underscore the critical importance of exquisitely regulating epithelial plasticity to balance stemness with epithelial differentiation in development and cancer. We report ChIPseq data illustrating Ovol2 genome-wide targets in mouse mammary epithelial cells, suggesting that Ovol2 regulates a plethora of genes associated with the EMT process. Immunoprecipitated samples from HC11 mouse mammary epithelial cells with antibodies against Ovol2 and control IgG respectively were used for ChIP-seq experiments.
Project description:Somatic DNA alteration underlies tumor development and progression, and gives rise to tumors with diverse genetic contexts. Here, we identify in a collection of 29 colorectal cancer cell lines and 226 primary colorectal tumors recurrent amplification of chromosome 13, an alteration highly restricted to colorectal-derived cancers. A minimal region of amplification on 13q12.2 pinpoints caudal type homeobox transcription factor CDX2, a master regulator of anterior-posterior patterning, midgut development, and intestinal epithelial cell differentiation and maintenance. In contrast to its described role as a colorectal tumor suppressor, we show that in the context of genomic amplification, CDX2 is required for proliferation and anchorage-independent growth of colorectal cancer cells. By genome-wide expression and location analysis, we reveal that CDX2 directly promotes expression of Wnt pathway genes. Further results suggest that CDX2 induces expression of intestinal differentiation markers and modulates β-catenin transcriptional activity. These data characterize CDX2 as a novel lineage-survival oncogene deregulated in colorectal cancer. ChIP-seq analysis of CDX2 binding sites in COLO320 cells
Project description:Epithelial cells possess remarkable plasticity, having the ability to become mesenchymal cells through alterations in adhesion and motility (epithelial-to-mesenchymal transition or EMT). Recent studies suggest that EMT endows differentiated epithelial cells with stem cell traits, posing the interesting question of how epithelial plasticity is properly restricted to ensure epithelial differentiation during tissue morphogenesis. Here we identify zinc-finger transcription factor Ovol2 as a key suppressor of EMT of mammary epithelial cells. Epithelia-specific deletion of Ovol2 completely arrests mammary ductal morphogenesis, and depletes epithelial stem/progenitor cell reservoirs. Further, Ovol2-deficient epithelial cells undergo EMT in vivo to become non-epithelial cell types, and that Ovol2 directly represses key EMT inducers such as Zeb1 and regulates stem/progenitor cell responsiveness to TGF-beta. We also provide evidence for a suppressive role of Ovol2 in breast cancer progression. Our findings underscore the critical importance of exquisitely regulating epithelial plasticity to balance stemness with epithelial differentiation in development and cancer. We report ChIPseq data illustrating Ovol2 genome-wide targets in mouse mammary epithelial cells, suggesting that Ovol2 regulates a plethora of genes associated with the EMT process.
Project description:Background: DNA hypermethylation at promoter CpG islands (CGIs) is a hallmark of cancers and could lead to dysregulation of gene expression in the development of cancers, however, its dynamics and regulatory mechanisms remain elusive. Bivalent genes, that direct development and differentiation of stem cells, are found to be frequent targets of hypermethylation in cancers. Results: Here we performed comprehensive analysis across multiple cancer types and identified that the decrease in H3K4me1 levels coincides with DNA hypermethylation at the bivalent promoter CGIs during tumorigenesis. Removal of DNA hypermethylation leads to increment of H3K4me1 at promoter CGIs with preference for bivalent genes. Nevertheless, the alteration of H3K4me1 by overexpressing or knockout LSD1, the demethylase of H3K4, doesn't change the level or pattern of DNA methylation. Moreover, LSD1 was found to regulate the expression of a bivalent gene OVOL2 to promote tumorigenesis. Knockdown of OVOL2 in LSD1 knockout HCT116 cells restored the cancer cell phenotype. Conclusion: In summary, our work identified a universal indicator that can pre-mark DNA hypermethylation in cancer cells, and dissected the interplay between H3K4me1 and DNA hypermethylation in detail. Current study also reveals a novel mechanism underlying the oncogenic role of LSD1, providing clues for cancer therapies.
Project description:Aberrant expression of SOX9 in human colorectal cancer cells suggests its roles in the development of colorectal cancer. To gain insight into SOX9-mediated transcriptional regulation in colorectal cancer cells, we attempted to identify its physiological targets on a genome-scale using chromatin immunoprecipitation (ChIP) followed by sequencing (ChIP-seq) in HT-29, human colorectal cancer cells. SOX9 CHIP-seq was carried out using HT-29 cells.
Project description:Epithelial cells possess remarkable plasticity, having the ability to become mesenchymal cells through alterations in adhesion and motility (epithelial-to-mesenchymal transition or EMT). Recent studies suggest that EMT endows differentiated epithelial cells with stem cell traits, posing the interesting question of how epithelial plasticity is properly restricted to ensure epithelial differentiation during tissue morphogenesis. Here we identify zinc-finger transcription factor Ovol2 as a key suppressor of EMT of mammary epithelial cells. Epithelia-specific deletion of Ovol2 completely arrests mammary ductal morphogenesis, and depletes epithelial stem/progenitor cell reservoirs. Further, Ovol2-deficient epithelial cells undergo EMT in vivo to become non-epithelial cell types, and that Ovol2 directly represses key EMT inducers such as Zeb1 and regulates stem/progenitor cell responsiveness to TGF-beta. We also provide evidence for a suppressive role of Ovol2 in breast cancer progression. Our findings underscore the critical importance of exquisitely regulating epithelial plasticity to balance stemness with epithelial differentiation in development and cancer. TEBs from control and conditional Ovol2-knockout mammary glands were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify primary changes, we analyzed TEBs from 24-25-day-old mice, when morphological differences between control and Ovol2 SSKO were still minimal.
Project description:The hypothesis that the onset and development of colorectal cancer result from the alteration of the close cooperation of mRNA-miRNA has gained increasing popularity. We performed a multifaceted enrichment analysis of hypernetworks, taking advantage of the simultaneous evaluation of transcriptome and miRNAome, to search deregulated micro-societies of mRNAs and miRNAs involved in signaling pathways that become critical when altered in colorectal carcinogenesis.
Project description:Somatic DNA alteration underlies tumor development and progression, and gives rise to tumors with diverse genetic contexts. Here, we identify in a collection of 29 colorectal cancer cell lines and 226 primary colorectal tumors recurrent amplification of chromosome 13, an alteration highly restricted to colorectal-derived cancers. A minimal region of amplification on 13q12.2 pinpoints caudal type homeobox transcription factor CDX2, a master regulator of anterior-posterior patterning, midgut development, and intestinal epithelial cell differentiation and maintenance. In contrast to its described role as a colorectal tumor suppressor, we show that in the context of genomic amplification, CDX2 is required for proliferation and anchorage-independent growth of colorectal cancer cells. By genome-wide expression and location analysis, we reveal that CDX2 directly promotes expression of Wnt pathway genes. Further results suggest that CDX2 induces expression of intestinal differentiation markers and modulates b-catenin transcriptional activity. These data characterize CDX2 as a novel lineage-survival oncogene deregulated in colorectal cancer.
Project description:Somatic DNA alteration underlies tumor development and progression, and gives rise to tumors with diverse genetic contexts. Here, we identify in a collection of 29 colorectal cancer cell lines and 226 primary colorectal tumors recurrent amplification of chromosome 13, an alteration highly restricted to colorectal-derived cancers. A minimal region of amplification on 13q12.2 pinpoints caudal type homeobox transcription factor CDX2, a master regulator of anterior-posterior patterning, midgut development, and intestinal epithelial cell differentiation and maintenance. In contrast to its described role as a colorectal tumor suppressor, we show that in the context of genomic amplification, CDX2 is required for proliferation and anchorage-independent growth of colorectal cancer cells. By genome-wide expression and location analysis, we reveal that CDX2 directly promotes expression of Wnt pathway genes. Further results suggest that CDX2 induces expression of intestinal differentiation markers and modulates β-catenin transcriptional activity. These data characterize CDX2 as a novel lineage-survival oncogene deregulated in colorectal cancer.
Project description:Somatic DNA alteration underlies tumor development and progression, and gives rise to tumors with diverse genetic contexts. Here, we identify in a collection of 29 colorectal cancer cell lines and 226 primary colorectal tumors recurrent amplification of chromosome 13, an alteration highly restricted to colorectal-derived cancers. A minimal region of amplification on 13q12.2 pinpoints caudal type homeobox transcription factor CDX2, a master regulator of anterior-posterior patterning, midgut development, and intestinal epithelial cell differentiation and maintenance. In contrast to its described role as a colorectal tumor suppressor, we show that in the context of genomic amplification, CDX2 is required for proliferation and anchorage-independent growth of colorectal cancer cells. By genome-wide expression and location analysis, we reveal that CDX2 directly promotes expression of Wnt pathway genes. Further results suggest that CDX2 induces expression of intestinal differentiation markers and modulates b-catenin transcriptional activity. These data characterize CDX2 as a novel lineage-survival oncogene deregulated in colorectal cancer.