Time filter

Source Type

Saint-Sauveur-en-Rue, France

Allain B.,University of Paris Descartes | Jarray R.,University of Paris Descartes | Borriello L.,University of Paris Descartes | Leforban B.,Tragex Pharma | And 10 more authors.
Cellular Signalling | Year: 2012

Recently, we identified a new Vascular Endothelial Growth Factor (VEGF)-A 165-induced gene Phactr-1, (Phosphatase Actin Regulator-1). We reported that Phactr-1 gene silencing inhibited tube formation in human umbilical endothelial cells (HUVECs) indicating a key role for Phactr-1 in tubulogenesis in vitro. In this study, we investigated the role of Phactr-1 in several cellular processes related to angiogenesis. We found that neuropilin-1 (NRP-1) and VEGF-R1 depletion inhibited Phactr-1 mRNA expression while NRP-2 and VEGF-R2 depletion had no effect. We described a new interaction site of VEGF-A 165 to VEGF-R1 in peptides encoded by exons 7 and 8 of VEGF-A 165. The specific inhibition of VEGF-A 165 binding on NRP-1 and VEGF-R1 by ERTCRC and CDKPRR peptides decreased the Phactr-1 mRNA levels in HUVECs indicating that VEGF-A 165-dependent regulation of Phactr-1 expression required both NRP-1 and VEGF-R1 receptors. In addition, upon VEGFA 165-stimulation Phactr-1 promotes formation and maintenance of cellular tubes through NRP-1 and VEGFR1. Phactr-1 was previously identified as protein phosphatase 1 (PP1) α-interacting protein that possesses actin-binding domains. We showed that Phactr-1 depletion decreased PP1 activity, disrupted the fine-tuning of actin polymerization and impaired lamellipodial dynamics. Taken together our results strongly suggest that Phactr-1 is a key component in the angiogenic process. © 2011 Elsevier Inc.

Liu W.-Q.,University of Paris Descartes | Megale V.,University of Paris Descartes | Borriello L.,University of Paris Descartes | Leforban B.,University of Paris Descartes | And 15 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2014

Neuropilins (NRPs) are VEGF-A165 co-receptors over-expressed in tumor cells, and considered as targets in angiogenic-related pathologies. We previously identified compound 1, the first non-peptidic antagonist of the VEGF-A165/NRP binding, which exhibits in vivo anti-angiogenic and anti-tumor activities. We report here the synthesis and biological evaluations of new antagonists structurally-related to compound 1. Among these molecules, 4a, 4c and 4d show cytotoxic effects on HUVEC and MDA-MB-31 cells, and antagonize VEGF-A165/NRP-1 binding. This study confirmed our key structure-activity relationships hypothesis and paved the way to compound 1 'hit to lead' optimization. © 2014 Elsevier Ltd. All rights reserved.

Borriello L.,University of Paris Descartes | Montes M.,French National Conservatory of Arts and Crafts | Lepelletier Y.,French Institute of Health and Medical Research | Lepelletier Y.,Paris-Sorbonne University | And 15 more authors.
Cancer Letters | Year: 2014

Neuropilin-1/-2 (+33 NRPs), VEGF-A165 co-receptors, are over-expressed during cancer progression. Thus, NRPs targeted drug development is challenged using a multistep in silico/in vitro screening procedure. The first fully non-peptidic VEGF-A165/NRPs protein-protein interaction antagonist (IC50=34μM) without effect on pro-angiogenic kinases has been identified (compound-1). This hit showed breast cancer cells anti-proliferative activity (IC50=0.60μM). Compound-1 treated NOG-xenografted mice significantly exerted tumor growth inhibition, which is correlated with Ki-67low expression and apoptosis. Furthermore, CD31+/CD34+ vessels are reduced in accordance with HUVEC-tube formation inhibition (IC50=0.20μM). Taking together, compound-1 is the first fully organic inhibitor targeting NRPs. © 2014 Elsevier Ireland Ltd.

Goldwaser E.,The Saints | Goldwaser E.,University Pierre and Marie Curie | de Courcy B.,University Pierre and Marie Curie | Demange L.,The Saints | And 6 more authors.
Journal of Molecular Modeling | Year: 2014

We investigate the conformational properties of a potent inhibitor of neuropilin-1, a protein involved in cancer processes and macular degeneration. This inhibitor consists of four aromatic/conjugated fragments: a benzimidazole, a methylbenzene, a carboxythiourea, and a benzene-linker dioxane, and these fragments are all linked together by conjugated bonds. The calculations use the SIBFA polarizable molecular mechanics procedure. Prior to docking simulations, it is essential to ensure that variations in the ligand conformational energy upon rotations around its six main-chain torsional bonds are correctly represented (as compared to high-level ab initio quantum chemistry, QC). This is done in two successive calibration stages and one validation stage. In the latter, the minima identified following independent stepwise variations of each of the six main-chain torsion angles are used as starting points for energy minimization of all the torsion angles simultaneously. Single-point QC calculations of the minimized structures are then done to compare their relative energies ΔEconf to the SIBFA ones. We compare three different methods of deriving the multipoles and polarizabilities of the central, most critical moiety of the inhibitor: carboxythiourea (CTU). The representation that gives the best agreement with QC is the one that includes the effects of the mutual polarization energy Epol between the amide and thioamide moieties. This again highlights the critical role of this contribution. The implications and perspectives of these findings are discussed. © 2014, Springer-Verlag Berlin Heidelberg.

Jarray R.,University of Paris Descartes | Allain B.,University of Paris Descartes | Borriello L.,University of Paris Descartes | Biard D.,French Atomic Energy Commission | And 8 more authors.
Biochimie | Year: 2011

Using suppression subtractive hybridisation (SSH), we identified a hitherto unreported gene PHACTR-1 (Phosphatase Actin Regulating Protein-1) in Human Umbilical Vascular Endothelial Cells (HUVECs). PHACTR-1 is an actin and protein phosphatase 1 (PP1) binding protein which is reported to be highly expressed in brain and which controls PP1 activity and F-actin remodelling. We have also reported that its expression is dependent of Vascular Endothelial Growth Factor (VEGF-A 165). To study its function in endothelial cells, we used a siRNA strategy against PHACTR-1. PHACTR-1 siRNA-treated HUVECs showed a major impairment of tube formation and stabilisation. PHACTR-1 depletion triggered apoptosis through death receptors DR4, DR5 and FAS, which was reversed using death receptor siRNAs or with death receptor-dependent caspase-8 siRNA. Our findings suggest that PHACTR-1 is likely to be a key regulator of endothelial cell function properties. Because of its central role in the control of tube formation and endothelial cell survival, PHACTR-1 may represent a new target for the development of anti-angiogenic therapy. © 2011 Elsevier Masson SAS. All rights reserved.

Discover hidden collaborations