Project description:Wnt inhibitory factor 1 (WIF1) is a marker of osteoblastic differentiation stage and is not silenced by DNA methylation in osteosarcoma
Project description:Therapeutic targeting of the Wnt pathway is of high clinical interest for treating bone loss disorders such as osteoporosis. These therapies inhibit the action of negative regulators of osteoblastic Wnt signaling. The observation that Wnt inhibitory factor 1 (WNT1) was epigenetic silencing in osteosarcoma (OS) raised concerns for such a treatment approach. In this study, genome-wide methylation profiling of OS derived from mouse models demonstrated Wif1 silencing in OS is not driven by DNA methylation. Treatment of mouse and human OS cells with methylation and HDAC inhibitors showed Wif1 was unresponsive to methylation inhibition but responded robustly to HDAC inhibition. Consistent with an HDAC dependent mechanism of silencing, the Wif1 locus in OS was characterized by low levels of acetylation and a bivalent H3K4/H3K27 trimethylation state. Wif1 expression marked late stages of normal osteoblast development and stratified OS tumours based on differentiation stage across species. Culture of human and mouse OS cells under differentiation inductive conditions increased expression of Wif1 in parallel with known osteoblast differentiation markers. Together these results demonstrate that Wif1 is not targeted for silencing by DNA methylation in OS. The reduced expression of Wif1 in OS cells is in context with their stage in differentiation. 3 cell lines derived from primary tumors from p53 Rb Osterix-Cre:lox OS model, 3 Osteoblasts (differentiated Kusa4b10 cells (21 days under osteoblastic differentiation conditions)
Project description:Wnt inhibitory factor 1 (WIF1) is a marker of osteoblastic differentiation stage and is not silenced by DNA methylation in osteosarcoma (methylation)
Project description:Wnt inhibitory factor 1 (WIF1) is not silenced by DNA methylation in osteosarcoma, and instead, represents a marker of osteoblastic differentiation stage (gene expression)
Project description:Therapeutic targeting of the Wnt pathway is of high clinical interest for treating bone loss disorders such as osteoporosis. These therapies inhibit the action of negative regulators of osteoblastic Wnt signaling. The observation that Wnt inhibitory factor 1 (WNT1) was epigenetic silencing in osteosarcoma (OS) raised concerns for such a treatment approach. In this study, genome-wide methylation profiling of OS derived from mouse models demonstrated Wif1 silencing in OS is not driven by DNA methylation. Treatment of mouse and human OS cells with methylation and HDAC inhibitors showed Wif1 was unresponsive to methylation inhibition but responded robustly to HDAC inhibition. Consistent with an HDAC dependent mechanism of silencing, the Wif1 locus in OS was characterized by low levels of acetylation and a bivalent H3K4/H3K27 trimethylation state. Wif1 expression marked late stages of normal osteoblast development and stratified OS tumours based on differentiation stage across species. Culture of human and mouse OS cells under differentiation inductive conditions increased expression of Wif1 in parallel with known osteoblast differentiation markers. Together these results demonstrate that Wif1 is not targeted for silencing by DNA methylation in OS. The reduced expression of Wif1 in OS cells is in context with their stage in differentiation.
Project description:Bone morphogenetic protein 4 (BMP4) is essential for lung development. To define its intracellular signaling mechanisms by which BMP4 regulates lung development, BMP-specific Smad1 or Smad5 was selectively knocked out in fetal mouse lung epithelial cells. Abrogation of lung epithelial-specific Smad1, but not Smad5, resulted in retardation of lung branching morphogenesis and reduced sacculation, accompanied by altered distal lung epithelial cell proliferation and differentiation, and consequently severe neonatal respiratory failure. By combining cDNA microarray with ChIP-chip analyses, Wnt inhibitory factor-1 (Wif1) was identified as a novel target gene of Smad1 in the developing mouse lung epithelial cells. Loss of Smad1 transcriptional activation of Wif1 expression was associated with reduced Wif1 expression and increased Wnt/beta-catenin signaling activity in lung epithelia, resulting in specific fetal lung abnormalities. Therefore, a novel regulatory loop of BMP4-Smad1-Wif1-Wnt/beta-catenin in coordinating BMP and Wnt pathways to control fetal lung development is suggested. mRNA profiling: Total RNA was isolated from left lobe lungs of three pair of E18.5 wild type and Smad1 lung epithelium-specific conditional knockout mice
Project description:Bone morphogenetic protein 4 (BMP4) is essential for lung development. To define its intracellular signaling mechanisms by which BMP4 regulates lung development, BMP-specific Smad1 or Smad5 was selectively knocked out in fetal mouse lung epithelial cells. Abrogation of lung epithelial-specific Smad1, but not Smad5, resulted in retardation of lung branching morphogenesis and reduced sacculation, accompanied by altered distal lung epithelial cell proliferation and differentiation, and consequently severe neonatal respiratory failure. By combining cDNA microarray with ChIP-chip analyses, Wnt inhibitory factor-1 (Wif1) was identified as a novel target gene of Smad1 in the developing mouse lung epithelial cells. Loss of Smad1 transcriptional activation of Wif1 expression was associated with reduced Wif1 expression and increased Wnt/beta-catenin signaling activity in lung epithelia, resulting in specific fetal lung abnormalities. Therefore, a novel regulatory loop of BMP4-Smad1-Wif1-Wnt/beta-catenin in coordinating BMP and Wnt pathways to control fetal lung development is suggested.
Project description:Glioblastoma is the most aggressive primary brain tumor in adults and due to the invasive nature it cannot be completely removed. We have recently shown that the WNT inhibitory factor 1 (WIF1), a secreted inhibitor of WNTs, is downregulated in glioblastoma and acts as strong tumor suppressor. In search of a mediator for this function differential gene expression profiles of WIF1-expressing cells were performed. MALAT1, a long non-coding RNA and key positive regulator of invasion, emerged as the top downregulated gene. Indeed, knock-down of MALAT1 reduced migration in glioblastoma cells, without effect on proliferation. LN-229 cells induced with Doxocyclin to express WIF1 were compared to the non-induced control (two biological replicates each)
Project description:Glioblastoma is the most aggressive primary brain tumor in adults and due to the invasive nature it cannot be completely removed. We have recently shown that the WNT inhibitory factor 1 (WIF1), a secreted inhibitor of WNTs, is downregulated in glioblastoma and acts as strong tumor suppressor. In search of a mediator for this function differential gene expression profiles of WIF1-expressing cells were performed. MALAT1, a long non-coding RNA and key positive regulator of invasion, emerged as the top downregulated gene. Indeed, knock-down of MALAT1 reduced migration in glioblastoma cells, without effect on proliferation.
Project description:The aim was to identify pathways and genes that are transcriptionally deregulated in osteosarcoma due to changes in CpG island DNA methylation. In order to identify candidates, we compared low passage cell cultures derived from a mouse model of osteosarcoma to mature osteoblasts derived by in vitro differentiation of the mouse bone marrow stromal cell line, Kusa4b10. Under cell culture osteoblastic differentiating conditions, Kusa4b10 cells acquire a mature osteoblastic phenotype (21 days). A potential role for DNA methylation in directing gene expression changes was established by integrating gene expression data with genome wide DNA methylation maps generated by methyl-DNA binding domain capture and NimbleGen promoter arrays (MBDCap-Chip). 3 cell lines derived from primary tumors from p53 Rb Osterix-Cre:lox OS model, 3 Osteoblasts (differentiated Kusa4b10 cells (21 days under osteoblastic differentiation conditions)