Project description:Epigenetic alterations appear to modulate Myc signaling. We investigated the role of the histone demethylase JMJD2B in Myc-mediated neuroblastoma pathogenesis. We demonstrate that Myc physically interacts with and recruits this epigenetic modifier, which removes repressive H3K9 methyl marks from Myc-target genes. JMJD2B regulates neuroblastoma proliferation and, together with MYCN amplification, identifies a subgroup of poor prognosis patients. We identify a novel histone demethylase inhibitor, ciclopirox, which targets JMJD2B and, consequently, Myc signaling, thereby inhibiting neuroblastoma proliferation and inducing differentiation. In xenograft studies, genetic and pharmacologic inhibition of JMJD2B resulted in significant tumor growth restriction. Our findings provide insight into epigenetic regulation of Myc via histone methylation and proof-of-concept for pharmacologic inhibition of histone demethylases to target Myc signaling in cancer. 8 samples were treated with vehicle or ciclopirox.
Project description:Epigenetic alterations appear to modulate Myc signaling. We investigated the role of the histone demethylase JMJD2B in Myc-mediated neuroblastoma pathogenesis. We demonstrate that Myc physically interacts with and recruits this epigenetic modifier, which removes repressive H3K9 methyl marks from Myc-target genes. JMJD2B regulates neuroblastoma proliferation and, together with MYCN amplification, identifies a subgroup of poor prognosis patients. We identify a novel histone demethylase inhibitor, ciclopirox, which targets JMJD2B and, consequently, Myc signaling, thereby inhibiting neuroblastoma proliferation and inducing differentiation. In xenograft studies, genetic and pharmacologic inhibition of JMJD2B resulted in significant tumor growth restriction. Our findings provide insight into epigenetic regulation of Myc via histone methylation and proof-of-concept for pharmacologic inhibition of histone demethylases to target Myc signaling in cancer. 8 samples were transfected with two different siRNAs for control, JMJD2B, MYCN and JARID1A.
Project description:Epigenetic alterations appear to modulate Myc signaling. We investigated the role of the histone demethylase JMJD2B in Myc-mediated neuroblastoma pathogenesis. We demonstrate that Myc physically interacts with and recruits this epigenetic modifier, which removes repressive H3K9 methyl marks from Myc-target genes. JMJD2B regulates neuroblastoma proliferation and, together with MYCN amplification, identifies a subgroup of poor prognosis patients. We identify a novel histone demethylase inhibitor, ciclopirox, which targets JMJD2B and, consequently, Myc signaling, thereby inhibiting neuroblastoma proliferation and inducing differentiation. In xenograft studies, genetic and pharmacologic inhibition of JMJD2B resulted in significant tumor growth restriction. Our findings provide insight into epigenetic regulation of Myc via histone methylation and proof-of-concept for pharmacologic inhibition of histone demethylases to target Myc signaling in cancer.
Project description:Epigenetic alterations appear to modulate Myc signaling. We investigated the role of the histone demethylase JMJD2B in Myc-mediated neuroblastoma pathogenesis. We demonstrate that Myc physically interacts with and recruits this epigenetic modifier, which removes repressive H3K9 methyl marks from Myc-target genes. JMJD2B regulates neuroblastoma proliferation and, together with MYCN amplification, identifies a subgroup of poor prognosis patients. We identify a novel histone demethylase inhibitor, ciclopirox, which targets JMJD2B and, consequently, Myc signaling, thereby inhibiting neuroblastoma proliferation and inducing differentiation. In xenograft studies, genetic and pharmacologic inhibition of JMJD2B resulted in significant tumor growth restriction. Our findings provide insight into epigenetic regulation of Myc via histone methylation and proof-of-concept for pharmacologic inhibition of histone demethylases to target Myc signaling in cancer.
Project description:Endothelial cells play an important role in maintenance of the vascular system and the repair after injury. Under pro-inflammatory conditions, endothelial cells can acquire a mesenchymal phenotype by a process named endothelial-to-mesenchymal transition (EndMT), which affects the functional properties of endothelial cells. Here, we investigated the epigenetic control of EndMT. We show that the histone demethylase JMJD2B is induced by EndMT promoting pro-inflammatory and hypoxic conditions. Silencing of JMJD2B reduced TGF-β2-induced expression of mesenchymal genes and prevented the alterations in endothelial morphology and impaired endothelial barrier function. Endothelial-specific deletion of JMJD2B in vivo confirmed a reduction of EndMT after myocardial infarction. EndMT did not affect global H3K9me3 levels but induced a site-specific reduction of repressive H3K9me3 marks at promoters of mesenchymal genes, such as Calponin (CNN1), and genes involved in TGF-β signaling, such as AKT Serine/Threonine Kinase 3 (AKT3) and sulfatase 1 (SULF1). Silencing of JMJD2B prevented the EndMT-induced reduction of H3K9me3 marks at these promotors and further repressed these EndMT-related genes. Our study reveals that endothelial identity and function is critically controlled by the histone demethylase JMJD2B, which is induced by EndMT-promoting pro-inflammatory and hypoxic conditions and support the acquirement of a mesenchymal phenotype.
Project description:Endothelial cells play an important role in maintenance of the vascular system and the repair after injury. Under pro-inflammatory conditions, endothelial cells can acquire a mesenchymal phenotype by a process named endothelial-to-mesenchymal transition (EndMT), which affects the functional properties of endothelial cells. Here, we investigated the epigenetic control of EndMT. We show that the histone demethylase JMJD2B is induced by EndMT promoting pro-inflammatory and hypoxic conditions. Silencing of JMJD2B reduced TGF-β2-induced expression of mesenchymal genes and prevented the alterations in endothelial morphology and impaired endothelial barrier function. Endothelial-specific deletion of JMJD2B in vivo confirmed a reduction of EndMT after myocardial infarction. EndMT did not affect global H3K9me3 levels but induced a site-specific reduction of repressive H3K9me3 marks at promoters of mesenchymal genes, such as Calponin (CNN1), and genes involved in TGF-β signaling, such as AKT Serine/Threonine Kinase 3 (AKT3) and sulfatase 1 (SULF1). Silencing of JMJD2B prevented the EndMT-induced reduction of H3K9me3 marks at these promotors and further repressed these EndMT-related genes. Our study reveals that endothelial identity and function is critically controlled by the histone demethylase JMJD2B, which is induced by EndMT-promoting pro-inflammatory and hypoxic conditions and support the acquirement of a mesenchymal phenotype.
Project description:The Hypoxia-Inducible Factors induce the expression of the histone demethylases JMJD1A (KDM3A) and JMJD2B (KDM4B), linking the hypoxic tumor microenvironment to epigenetic mechanisms that may foster tumor progression. Using transcript profiling, we have identified genes that are regulated by JMJD1A and JMJD2B in both normoxic and hypoxic conditions in SKOV3ip.1 ovarian cancer cells. This dataset includes expression data obtained from exposing ovarian cancer cells to hypoxia in combination with siRNA-mediated knockdown of the hypoxia-inducible histone demethylases JMJD1A and JMJD2B. These data were used to both identify functional overlap between each histone demethylase, as well as identify effectors of tumor growth mediated by JMJD2B (KDM4B) in normoxia and hypoxia.
Project description:p53 inactivation occurs only rarely in neuroblastoma, although miR-34, a transcriptional target of p53, is often deleted in neuroblastoma, suggesting another way in which p53 signaling might be impaired. In this study we show that miR-34 directly targets and downregulates the Polycomb Repressive Complex 2 (PRC2) and its associated histone demethylase, JARID1A, in a p53-dependent manner, 8 samples were transfected with siRNA control or JMJD2B, MYCN, JARID1A into NB1691 cells.