5 research outputs found
Epigenetic regulation of angiogenesis
DNA methylation and histone deacetylation are two key epigenetic modifications that play central role in regulation of gene expression. Several studies have shown that histone deacetylases (HDAC) and DNA methyltransferases (DNMT) inhibitors are potent anti-angiogenic compounds. Though combination of HDAC and DNMT inhibitors are now being examined in clinical trials of hematological malignancies, little work has been done to understand the effect of this combination on physiological and tumoral angiogenesis. We designed a family of twin drugs with intrinsic HDAC and DNMT inhibitory activities and tested in relevant models of angiogenesis in vitro (Human Umbilical Vein Endothelial Cells – HUVEC and aortic ring) and in vivo (chick chorioallantoic membrane and Zebrafish). We have identified a lead compound (EPI) affecting global histone acetylation and having quantifiable anti-angiogenic action without cytotoxic and apoptotic effect. In order to elucidate its anti-angiogenic mechanism, we characterized gene expression pattern simultaneously with the methylation profile of HUVEC cells treated with EPI and reference epigenetic modulators. This approach based on parallel microarray analyses permitted us to underscore a list of genes exclusively affected by EPI but not by other HDAC or DNMT inhibitors. These genes were then analyzed using the Ingenuity Pathway Analysis software revealing potential involvement of a subset of genes in angiogenesis. Our present aim is to validate the expression levels of a series of genes with respect to epigenetic mechanisms (histone modifications and DNA methylation). Finally, the biological relevance of the target genes will be explored by RNA silencing. Hence, we are using these novel epigenetic modulators as a tool to understand the regulatory mechanism of angiogenesis and to develop effective approaches to treat cancer
Understanding angiogenesis through novel epigenetic modulators
DNA methylation and histone deacetylation are two key epigenetic modifications that play central role in regulation of gene expression. Several studies have shown that histone deacetylases (HDAC) and DNA methyltransferases (DNMT) inhibitors are potent anti-angiogenic compounds. Though combination of HDAC and DNMT inhibitors are now being examined in clinical trials of hematological malignancies, little work has been done to understand the effect of this combination on physiological and tumoral angiogenesis. We have designed and tested a family of twin drugs with intrinsic HDAC and DNMT inhibitory activities in relevant models of angiogenesis in vitro (Human Umbilical Vein Endothelial Cells – HUVEC and aortic ring) and in vivo (chick chorioallantoic membrane and Zebrafish). We have identified a lead compound having quantifiable anti-angiogenic effect without cytotoxicity affecting global histone acetylation and DNA methylation levels. In order to elucidate its anti-angiogenic mechanism, we characterized gene expression pattern simultaneously with the methylation profile of HUVEC cells treated with the lead compound and reference epigenetic modulators. This approach based on parallel microarray analyses permitted us to underscore a list of genes exclusively affected by the lead compound but not by other HDAC or DNMT inhibitors. These genes were then analyzed using the Ingenuity Pathway software revealing potential involvement of a subset of genes in angiogenesis. Our present work is focused on exploring the exact role of these genes on angiogenesis using RNA silencing and vectors cloned with genes of interest. We are using these novel epigenetic modulators as a tool to understand the regulatory mechanism of angiogenesis and to develop effective approaches to treat cancer
Novel HDAC/DNMT Twin inhibitors interfere with angiogenesis
DNA methylation and histone deacetylation are two key epigenetic modifications that play central role in regulation of gene expression. Several studies have shown that histone deacetylases (HDAC) and DNA methyltransferases (DNMT) inhibitors are potent anti-angiogenic compounds. Though combination of HDAC and DNMT inhibitors are now being examined in clinical trials of hematological malignancies, little work has been done to understand the effect of this combination on physiological and tumoral angiogenesis. We have designed and tested a family of twin drugs with intrinsic HDAC and DNMT inhibitory activities in relevant models of angiogenesis in vitro (Human Umbilical Vein Endothelial Cells – HUVEC and aortic ring) and in vivo (chick chorioallantoic membrane and Zebrafish). We have identified a lead compound having quantifiable anti-angiogenic effect without cytotoxicity affecting global histone acetylation and DNA methylation levels. In order to elucidate its anti-angiogenic mechanism, we characterized gene expression pattern simultaneously with the methylation profile of HUVEC cells treated with the lead compound and reference epigenetic modulators. This approach based on parallel microarray analyses permitted us to underscore a list of genes exclusively affected by the lead compound but not by other HDAC or DNMT inhibitors. These genes were then analyzed using the Ingenuity Pathway software revealing potential involvement of a subset of genes in angiogenesis. Our present aim is to validate the expression levels of a series of genes with respect to epigenetic mechanisms (histone modifications and DNA methylation). Finally, the biological relevance of the target genes will be explored by RNA silencing. Hence, we are using these novel epigenetic modulators as a tool to understand the regulatory mechanism of angiogenesis and to develop effective approaches to treat cancer
Novel HDAC/DNMT twin inhibitors interfere with angiogenesis
DNA methylation and histone deacetylation are two key epigenetic modifications that play central role in regulation of gene expression. Several studies have shown that histone deacetylases (HDAC) and DNA methyltransferases (DNMT) inhibitors are potent antiangiogenic compounds. Though combination of HDAC and DNMT inhibitors are now being examined in clinical trials of hematological malignancies, very little work has been done to understand the effect of this combination on normal and tumoral angiogenesis. We have designed and tested a family of twin drugs with intrinsic HDAC and DNMT inhibitory activities in relevant models of angiogenesis in vitro (endothelial cells, pericytes and the 3D aortic ring assay) and in vivo (the chick chorioallantoic membrane assay). We have identified a lead compound having quantifiable antiangiogenic effect without cytotoxicity associated with increased global acetylation and decreased DNA methylation levels. This compound is presently used to develop effective approaches to treat cancer by modulating the process of angiogenesis
Tyrosine Dephosphorylation of the Syndecan-1 PDZ Binding Domain Regulates Syntenin-1 Recruitment*
Heparan sulfate proteoglycan receptor syndecan-1 interacts with the
carboxyl-terminal LG4/5 domain in laminin 332 (α3LG4/5) and participates
in cell adhesion and spreading. To dissect the function of syndecan-1 in these
processes, we made use of a cell adhesion model in which syndecan-1
exclusively interacts with a recombinantly expressed α3LG4/5 fragment.
Plating HT1080 cells on this fragment induces the formation of
actin-containing protrusive structures in an integrin-independent manner. Here
we show that syndecan-1-mediated formation of membrane protrusions requires
dephosphorylation of tyrosine residues in syndecan-1. Accordingly, inhibition
of phosphatases with orthovanadate decreases cell adhesion to the
α3LG4/5 fragment. We demonstrate that the PDZ-containing protein
syntenin-1, known to connect cytoskeletal proteins, binds to syndecan-1 in
cells plated on the α3LG4/5 fragment and participates in the formation
of membrane protrusions. We further show that syntenin-1 recruitment depends
on the dephosphorylation of Tyr-309 located within syndecan-1 PDZ binding
domain EFYA. We propose that tyrosine dephosphorylation of syndecan-1 may
regulate its association with cytoskeleton components