Project description:The Epithelial–Mesenchymal Transition (EMT) and primary ciliogenesis induce stem cell properties in basal Mammary Stem Cells (MaSCs) to promote mammogenesis, but the underlying mechanisms remain incompletely understood. Here, we show that EMT transcription factors promote ciliogenesis upon intermediate EMT transition states by activating ciliogenesis inducers, including FGFR1. The resulting primary cilia promote BBS11-dependent ubiquitination and inactivation of a central signaling node, GLIS2. We show that GLIS2 inactivation promotes MaSC stemness, and GLIS2 is required for normal mammary gland development. Moreover, GLIS2 inactivation is required to induce the proliferative and tumorigenic capacities of the Mammary-Tumor-initiating cells (MaTICs) of claudin-low breast cancers. Claudin-low breast tumors can be segregated from other breast tumor subtypes based on a GLIS2-dependent gene expression signature. Collectively, our findings establish molecular mechanisms by which EMT programs induce ciliogenesis to control MaSC and MaTIC biology, mammary gland development, and claudin-low breast cancer formation.
Project description:Cancer stem cells (CSCs) are proposed to be responsible for metastatic dissemination and clinical relapse in a variety of cancers. Analogies between CSCs and normal tissue stem cells (SC) has led to the notion that CSCs often co-opt the normal SC program of their tissue-of-origin. The cell-biological program termed epithelial-mesenchymal transition (EMT) has been found to encourage entrance of normal and neoplastic mammary cells into the corresponding SC states. Using genetically engineered knock-in reporter mouse lines, we demonstrate that in the murine mammary lineage, the paralogous EMT-inducing transcription factors Snail and Slug, are selectively exploited by CSCs and normal SCs respectively. Slug, when expressed at physiological levels, only activates a partial EMT program and is dispensable in CSCs. In contrast, Snail drives a far more complete transition into the mesenchymal state and controls both tumor-initiation and metastatic dissemination. Consistent with their functional distinctions, Snail controls far more target genes than Slug, and their distinct functions are determined by their divergent N-terminal domains. Our findings underscore fundamental distinctions between the SC program operating in normal and neoplastic SCs, and hint for potential avenues of selective therapeutic elimination of breast CSCs. We sought to understand differential ability to activate the EMT program in breast cancer cells by transcription factors Snail and Slug. Hence, we mapped genome-wide Snail and Slug binding sites in murine MMTV-PyMT breast cancer cell lines that express high level of Snail or high level of Slug respectively. Specifically, we performed Snail ChIP seq in the mesenchymal pBl.3G cells, and Slug ChIP-seq in the epithelial pBl.1G cells.
Project description:Cancer stem cells (CSCs) are proposed to be responsible for metastatic dissemination and clinical relapse in a variety of cancers. Analogies between CSCs and normal tissue stem cells (SC) has led to the notion that CSCs often co-opt the normal SC program of their tissue-of-origin. The cell-biological program termed epithelial-mesenchymal transition (EMT) has been found to encourage entrance of normal and neoplastic mammary cells into the corresponding SC states. Using genetically engineered knock-in reporter mouse lines, we demonstrate that in the murine mammary lineage, the paralogous EMT-inducing transcription factors Snail and Slug, are selectively exploited by CSCs and normal SCs respectively. Slug, when expressed at physiological levels, only activates a partial EMT program and is dispensable in CSCs. In contrast, Snail drives a far more complete transition into the mesenchymal state and controls both tumor-initiation and metastatic dissemination. Consistent with their functional distinctions, Snail controls far more target genes than Slug, and their distinct functions are determined by their divergent N-terminal domains. Our findings underscore fundamental distinctions between the SC program operating in normal and neoplastic SCs, and hint for potential avenues of selective therapeutic elimination of breast CSCs.
Project description:Molecular/cellular events that associate with epithelial-to-mesenchymal transition (EMT) are linked to acquisition of cancer stem cell traits, but whether EMT mechanisms regulate tissue epithelial cell fate and stem cell activity in vivo remains ambiguous. Using single-cell RNA sequencing, we detect heterogeneous EMT gene expression in stem cell-containing mammary basal/myoepithelial cells that normally possess both epithelial and smooth muscle characteristics. We show that EMT-inducing transcription factor Zeb1 is required within the mammary epithelium for ductal branching morphogenesis and regeneration, and that it promotes basal cell fate and regulates stem cell proliferation dynamics. We provide genetic and molecular evidence for EMT-dependent and -independent mechanisms of Zeb1 function, and show that Zeb1 cooperates with YAP to directly activate targets that inhibit Wnt signaling or control cell cycle. Together, our findings underscore Zeb1-mediated EMT control in governing mammary basal cell fate and proliferative activity, but with an interesting turn that involves mechanisms beyond EMT.
Project description:Molecular/cellular events that associate with epithelial-to-mesenchymal transition (EMT) are linked to acquisition of cancer stem cell traits, but whether EMT mechanisms regulate tissue epithelial cell fate and stem cell activity in vivo remains ambiguous. Using single-cell RNA sequencing, we detect heterogeneous EMT gene expression in stem cell-containing mammary basal/myoepithelial cells that normally possess both epithelial and smooth muscle characteristics. We show that EMT-inducing transcription factor Zeb1 is required within the mammary epithelium for ductal branching morphogenesis and regeneration, and that it promotes basal cell fate and regulates stem cell proliferation dynamics. We provide genetic and molecular evidence for EMT-dependent and -independent mechanisms of Zeb1 function, and show that Zeb1 cooperates with YAP to directly activate targets that inhibit Wnt signaling or control cell cycle. Together, our findings underscore Zeb1-mediated EMT control in governing mammary basal cell fate and proliferative activity, but with an interesting turn that involves mechanisms beyond EMT.
Project description:Molecular/cellular events that associate with epithelial-to-mesenchymal transition (EMT) are linked to acquisition of cancer stem cell traits, but whether EMT mechanisms regulate tissue epithelial cell fate and stem cell activity in vivo remains ambiguous. Using single-cell RNA sequencing, we detect heterogeneous EMT gene expression in stem cell-containing mammary basal/myoepithelial cells that normally possess both epithelial and smooth muscle characteristics. We show that EMT-inducing transcription factor Zeb1 is required within the mammary epithelium for ductal branching morphogenesis and regeneration, and that it promotes basal cell fate and regulates stem cell proliferation dynamics. We provide genetic and molecular evidence for EMT-dependent and -independent mechanisms of Zeb1 function, and show that Zeb1 cooperates with YAP to directly activate targets that inhibit Wnt signaling or control cell cycle. Together, our findings underscore Zeb1-mediated EMT control in governing mammary basal cell fate and proliferative activity, but with an interesting turn that involves mechanisms beyond EMT.
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: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:In this study, we explored the molecular basis of site-specific metastasis of breast cancer to the lungs in a clinically relevant model based on the JygMC(A) cell line. In this dataset, we include expression data from JygMC(A) primary mammary tumors (carcinoma and EMT-like areas), lung metastases, normal mammary glands and normal lung parenchyma. In total, 36 laser microdissected samples were analyzed. We built a customized NanoString nCounter® Gene Expression Codeset of 104 genes and controls that contained significant embryonic core stem cell genes and EMT-MET markers. This customized assay was performed to target gene expression profiling on the following samples: primary tumor carcinoma, primary tumor EMT, lung metastasis, normal mammary gland and normal lung parenchyma.
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.