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Nature ; 558(7711): 540-546, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29899452


CLOVES syndrome (congenital lipomatous overgrowth, vascular malformations, epidermal naevi, scoliosis/skeletal and spinal syndrome) is a genetic disorder that results from somatic, mosaic gain-of-function mutations of the PIK3CA gene, and belongs to the spectrum of PIK3CA-related overgrowth syndromes (PROS). This rare condition has no specific treatment and a poor survival rate. Here, we describe a postnatal mouse model of PROS/CLOVES that partially recapitulates the human disease, and demonstrate the efficacy of BYL719, an inhibitor of PIK3CA, in preventing and improving organ dysfunction. On the basis of these results, we used BYL719 to treat nineteen patients with PROS. The drug improved the disease symptoms in all patients. Previously intractable vascular tumours became smaller, congestive heart failure was improved, hemihypertrophy was reduced, and scoliosis was attenuated. The treatment was not associated with any substantial side effects. In conclusion, this study provides the first direct evidence supporting PIK3CA inhibition as a promising therapeutic strategy in patients with PROS.

Nephrol Ther ; 13 Suppl 1: S155-S156, 2017 Apr.
Artigo em Francês | MEDLINE | ID: mdl-28577738


This review presents an overview of a recently characterized spectrum of overgrowth syndrome: phosphoinositide-3 kinase (PI3K)-related overgrowth spectrum (PROS). This spectrum encompasses overgrowth syndromes associated with somatic mosaic activating PIK3CA mutations such as megalencephaly-capillary malformation (MCAP) syndrome, dysplatic megalencephaly (DMEG), congenital lipomatous asymmetric overgrowth of the trunk, lymphatic, capillary, venous, and combined-type vascular malformations, epidermal nevi, skeletal and spinal anomalies (CLOVES) syndrome, hemihyperplasia-multiple lipomatosis (HHML), fibroadipose overgrowth and Klippel-Trenaunay syndrome. Mosaic gain of function mutation in PIK3CA gene leads to abnormal AKT-mTOR pathway activation and is responsible of the clinical manifestations. Here, we summarize the current knowledge on this disorder.

Anormalidades Múltiplas/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Transtornos do Crescimento/genética , Mutação , Anormalidades Múltiplas/diagnóstico , Biomarcadores/sangue , Transtornos do Crescimento/diagnóstico , Humanos , Lipomatose/genética , Anormalidades Musculoesqueléticas/genética , Fenótipo , Síndrome , Malformações Vasculares/genética
PLoS One ; 11(1): e0146962, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26789121


ABCB4/MDR3, a member of the ABC superfamily, is an ATP-dependent phosphatidylcholine translocator expressed at the canalicular membrane of hepatocytes. Defects in the ABCB4 gene are associated with rare biliary diseases. It is essential to understand the mechanisms of its canalicular membrane expression in particular for the development of new therapies. The stability of several ABC transporters is regulated through their binding to PDZ (PSD95/DglA/ZO-1) domain-containing proteins. ABCB4 protein ends by the sequence glutamine-asparagine-leucine (QNL), which shows some similarity to PDZ-binding motifs. The aim of our study was to assess the potential role of the QNL motif on the surface expression of ABCB4 and to determine if PDZ domain-containing proteins are involved. We found that truncation of the QNL motif decreased the stability of ABCB4 in HepG2-transfected cells. The deleted mutant ABCB4-ΔQNL also displayed accelerated endocytosis. EBP50, a PDZ protein highly expressed in the liver, strongly colocalized and coimmunoprecipitated with ABCB4, and this interaction required the QNL motif. Down-regulation of EBP50 by siRNA or by expression of an EBP50 dominant-negative mutant caused a significant decrease in the level of ABCB4 protein expression, and in the amount of ABCB4 localized at the canalicular membrane. Interaction of ABCB4 with EBP50 through its PDZ-like motif plays a critical role in the regulation of ABCB4 expression and stability at the canalicular plasma membrane.

Subfamília B de Transportador de Cassetes de Ligação de ATP/biossíntese , Membrana Celular/metabolismo , Regulação da Expressão Gênica/fisiologia , Hepatócitos/metabolismo , Fosfoproteínas/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Motivos de Aminoácidos , Membrana Celular/genética , Células HEK293 , Células Hep G2 , Hepatócitos/citologia , Humanos , Domínios PDZ , Fosfoproteínas/genética , Trocadores de Sódio-Hidrogênio/genética