TGF-β and RAS jointly unmask primed enhancers to drive metastasis (Mnase-Seq)
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ABSTRACT: Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. TGF-β and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here we demonstrate that both arms form a program for lung adenocarcinoma pulmonary metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-β and RAS dual inputs. RREB1 binds near H4K16ac histone marks and histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes IL11, PDGFB, and HAS2 and the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-β. These regulatory properties set the fibrogenic EMT program apart from RAS-independent TGF-β gene responses and illuminate the operation and vulnerabilities of a transcriptional program that promotes metastatic outgrowth.
Project description:Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. TGF-β and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here we demonstrate that both arms form a program for lung adenocarcinoma pulmonary metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-β and RAS dual inputs. RREB1 binds near H4K16ac histone marks and histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes IL11, PDGFB, and HAS2 and the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-β. These regulatory properties set the fibrogenic EMT program apart from RAS-independent TGF-β gene responses and illuminate the operation and vulnerabilities of a transcriptional program that promotes metastatic outgrowth.
Project description:Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. TGF-β and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here we demonstrate that both arms form a program for lung adenocarcinoma pulmonary metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-β and RAS dual inputs. RREB1 binds near H4K16ac histone marks and histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes IL11, PDGFB, and HAS2 and the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-β. These regulatory properties set the fibrogenic EMT program apart from RAS-independent TGF-β gene responses and illuminate the operation and vulnerabilities of a transcriptional program that promotes metastatic outgrowth.
Project description:Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. TGF-β and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here we demonstrate that both arms form a program for lung adenocarcinoma pulmonary metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-β and RAS dual inputs. RREB1 binds near H4K16ac histone marks and histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes IL11, PDGFB, and HAS2 and the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-β. These regulatory properties set the fibrogenic EMT program apart from RAS-independent TGF-β gene responses and illuminate the operation and vulnerabilities of a transcriptional program that promotes metastatic outgrowth.
Project description:Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. TGF-β and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here we demonstrate that both arms form a program for lung adenocarcinoma pulmonary metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-β and RAS dual inputs. RREB1 binds near H4K16ac histone marks and histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes IL11, PDGFB, and HAS2 and the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-β. These regulatory properties set the fibrogenic EMT program apart from RAS-independent TGF-β gene responses and illuminate the operation and vulnerabilities of a transcriptional program that promotes metastatic outgrowth.
Project description:Epithelial-to-mesenchymal transitions (EMT) play prominent roles during development, regeneration and tumor progression. EMTs are triggered by TGF-β, RAS and other signals that cooperatively induce the expression of master EMT transcription factors such as SNAIL. Here, we elucidate how the TGF-β and RAS pathways jointly trigger EMTs and tie them to broader developmental programs. We identify RAS response element binding protein 1 (RREB1) as a critical partner of TGF-β-activated SMAD transcription factors in driving SNAIL expression in pancreatic pre-malignant epithelial cells, lung adenocarcinoma cells, and embryonic stem cells. Moreover, SMADs and RREB1 also drive EMT-associated fibrogenic programs in epithelial cells and mesendoderm differentiation in pluripotent embryonic cells. These findings illuminate the orchestration of EMT associated programs in gastrulation, fibrosis, and cancer.
Project description:Epithelial-to-mesenchymal transitions (EMT) play prominent roles during development, regeneration and tumor progression. EMTs are triggered by TGF-β, RAS and other signals that cooperatively induce the expression of master EMT transcription factors such as SNAIL. Here, we elucidate how the TGF-β and RAS pathways jointly trigger EMTs and tie them to broader developmental programs. We identify RAS response element binding protein 1 (RREB1) as a critical partner of TGF-β-activated SMAD transcription factors in driving SNAIL expression and EMT program in mammary gland epithelial cells.
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. 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.