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. This dataset includes expression data obtained from exposing colon carcinoma cells to hypoxia in combination with siRNA-mediated knockdown of the hypoxia-inducible histone demethylases JMJD1A and JMJD2B.
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 in RCC4 with siRNA-mediated knockdown of JMJD1A and JMJD2B. This dataset includes expression data obtained from renal cell Carcinoma being loss or mutation of the von Hippel-Lindau (VHL) tumor suppressor gene combination with siRNA-mediated knockdown of histone demethylases JMJD1A and JMJD2B.
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: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:Patient-derived TIC cultures T6 and T18 were used to study the effect of normoxic vs. hypoxic culture conditions The main focus of the study was the identification and validation of new hypoxia-responsive miRNAs and target genes in such colon TICs
Project description:Hypoxia is one of the major driving forces mediating tumor angiogenesis, aggressiveness, as well as resistance to chemo- and radiotherapy. It has also been suggested to play important roles in stem cell maintenance for both normal and cancer tissues. However, the mechanisms by which hypoxia-driven epigenetic changes modulate tumorigenesis remain poorly understood. As the histone H3 lysine 9 (H3K9) demethylase Jmjd1a and methyltransferase G9a are upregulated downstream targets of hypoxia, we focused on these two catalytically opposing epigenetic modifiers to address this question. Through the use of homozygous Jmjd1a and G9a knockout mouse embryonic stem (ES) cells, we found that Jmjd1a was not required for stem cell self-renewal and that anti-angiogenesis related genes were epigenetically dysregulated in both Jmjd1a- and G9a deficient ES cells under hypoxic conditions, accompanied by corresponding changes in H3K9 dimethylation and H3K4 trimethylation levels in the proximal promoter regions of these target genes. Most importantly, these genetic alterations led to opposing tumor phenotypes: loss of Jmjd1a results in increased tumor growth, whereas loss of G9a produces smaller tumors. These findings provide new insights on the importance of hypoxia signalling in regulating the epigenetic status and expression of angiogenesis genes that promote tumor progression.
Project description:Hypoxia is one of the major driving forces mediating tumor angiogenesis, aggressiveness, as well as resistance to chemo- and radiotherapy. It has also been suggested to play important roles in stem cell maintenance for both normal and cancer tissues. However, the mechanisms by which hypoxia-driven epigenetic changes modulate tumorigenesis remain poorly understood. As the histone H3 lysine 9 (H3K9) demethylase Jmjd1a and methyltransferase G9a are upregulated downstream targets of hypoxia, we focused on these two catalytically opposing epigenetic modifiers to address this question. Through the use of homozygous Jmjd1a and G9a knockout mouse embryonic stem (ES) cells, we found that Jmjd1a was not required for stem cell self-renewal and that anti-angiogenesis related genes were epigenetically dysregulated in both Jmjd1a- and G9a deficient ES cells under hypoxic conditions, accompanied by corresponding changes in H3K9 dimethylation and H3K4 trimethylation levels in the proximal promoter regions of these target genes. Most importantly, these genetic alterations led to opposing tumor phenotypes: loss of Jmjd1a results in increased tumor growth, whereas loss of G9a produces smaller tumors. These findings provide new insights on the importance of hypoxia signalling in regulating the epigenetic status and expression of angiogenesis genes that promote tumor progression. 63 microarray samples consisting of 7 mouse ES cell lines of which 2 are wild type (control), 2 Jmjd1a knockout, 2 G9a knockout and 1 G9a knockout that was reconstituted for G9a (G9a control). Each cell line and condition was seeded at 3 different densities (2X10^5, 4X10^5 and 6X10^5) in 6 cm dishes to control for the effects of cell confluency on gene expression. 18 hours after plating, the cells were subjected to normoxia (21% O2) for 24 hours (control), normoxia 20 hours followed by hypoxia (1% O2) for 4 hours (acute hypoxia) and 24 hours hypoxia (chronic treatment). Total RNA was harvested from all samples for microarrays after the 24 hour treatments.