title: Somatic Activating PIK3CA Mutations Cause Venous Malformation.
abstract: Somatic mutations in TEK, the gene encoding endothelial cell tyrosine kinase receptor TIE2, cause more than half of sporadically occurring unifocal venous malformations (VMs). Here, we report that somatic mutations in PIK3CA, the gene encoding the catalytic p110α subunit of PI3K, cause 54% (27 out of 50) of VMs with no detected TEK mutation. The hotspot mutations c.1624G>A, c.1633G>A, and c.3140A>G (p.Glu542Lys, p.Glu545Lys, and p.His1047Arg), frequent in PIK3CA-associated cancers, overgrowth syndromes, and lymphatic malformation (LM), account for >92% of individuals who carry mutations. Like VM-causative mutations in TEK, the PIK3CA mutations cause chronic activation of AKT, dysregulation of certain important angiogenic factors, and abnormal endothelial cell morphology when expressed in human umbilical vein endothelial cells (HUVECs). The p110α-specific inhibitor BYL719 restores all abnormal phenotypes tested, in PIK3CA- as well as TEK-mutant HUVECs, demonstrating that they operate via the same pathogenic pathways. Nevertheless, significant genotype-phenotype correlations in lesion localization and histology are observed between individuals with mutations in PIK3CA versus TEK, pointing to gene-specific effects.
authors.affiliation: Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium.
authors.forename: Nisha
authors.initials: N
authors.lastname: Limaye
authors.affiliation: Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, 90014 Oulu, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kangas
authors.affiliation: Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium.
authors.forename: Antonella
authors.initials: A
authors.lastname: Mendola
authors.affiliation: Clermont Université, Université d'Auvergne, 63000 Clermont-Ferrand, France; Service d'Anatomopathologie, Hôpital Gabriel Montpied, Centre Hospitalier Universitaire Clermont-Ferrand, 63000 Clermont-Ferrand, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Godfraind
authors.affiliation: Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium.
authors.forename: Matthieu J
authors.initials: MJ
authors.lastname: Schlögel
authors.affiliation: Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium.
authors.forename: Raphael
authors.initials: R
authors.lastname: Helaers
authors.affiliation: Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, 90014 Oulu, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Eklund
authors.affiliation: Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium; Center for Vascular Anomalies, Division of Plastic Surgery, Cliniques Universitaires Saint-Luc and Université Catholique de Louvain, 1200 Brussels, Belgium.
authors.forename: Laurence M
authors.initials: LM
authors.lastname: Boon
authors.affiliation: Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium. Electronic address: miikka.vikkula@uclouvain.be.
authors.forename: Miikka
authors.initials: M
authors.lastname: Vikkula
mesh_terms: D000483:Alleles; D058534:Class I Phosphatidylinositol 3-Kinases; D005786:Gene Expression Regulation; D005787:Gene Frequency; D056726:Genetic Association Studies; D059014:High-Throughput Nucleotide Sequencing; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D006801:Humans; D009154:Mutation; D009389:Neovascularization, Pathologic / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D042787:Receptor, TIE-2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013844:Thiazoles / Q000494:pharmacology; D014162:Transfection; D054079:Vascular Malformations / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D014680:Veins / Q000201:enzymology / Q000473:pathology
chemical_list: D058534:Class I Phosphatidylinositol 3-Kinases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D042787:Receptor, TIE-2; D013844:Thiazoles; C585539:Alpelisib; C484760:PIK3CA protein, human