Clinical and functional characterization of germline PIK3CA variants in patients with PIK3CA-related overgrowth spectrum disorders

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragen

Beitragende

  • Jessica A Cooley Coleman - , Greenwood Genetic Center (Autor:in)
  • Jennifer M Gass - , Greenwood Genetic Center (Autor:in)
  • Sujata Srikanth - , Greenwood Genetic Center (Autor:in)
  • Rini Pauly - , Greenwood Genetic Center (Autor:in)
  • Catherine A Ziats - , Greenwood Genetic Center (Autor:in)
  • David B Everman - , Greenwood Genetic Center (Autor:in)
  • Steven A Skinner - , Greenwood Genetic Center (Autor:in)
  • Shannon Bell - , Greenwood Genetic Center (Autor:in)
  • Raymond J Louie - , Greenwood Genetic Center (Autor:in)
  • Lauren Cascio - , Greenwood Genetic Center (Autor:in)
  • Wesley G Patterson - , Greenwood Genetic Center (Autor:in)
  • Julie R Jones - , Greenwood Genetic Center (Autor:in)
  • Nataliya Di Donato - , Institut für Klinische Genetik, Universitäts KrebsCentrum Dresden (Autor:in)
  • Roger E Stevenson - , Greenwood Genetic Center (Autor:in)
  • Luigi Boccuto - , Greenwood Genetic Center (Autor:in)

Abstract

Mosaic variants in the PIK3CA gene, encoding the catalytic subunit of phosphoinositide 3-kinase (PI3K), produce constitutive PI3K activation, which causes PIK3CA-related overgrowth spectrum disorders. To date, fewer than 20 patients have been described with germline alterations in PIK3CA. In this study, we describe three unrelated individuals with overgrowth and germline PIK3CA variants. These variants were discovered through whole-exome sequencing and confirmed as germline by testing multiple tissue types, when available. Functional analysis using Patient 1's fibroblast cell line and two previously reported patients' cell lines showed increased phosphorylation of AKT during cellular starvation revealing constitutive activation of the phosphoinositide-3-kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) pathway. Alternatively, stimulation of the cells by fetal bovine serum produced a reduced response, indicating an activated status of the PI3K complex reducing the pathway response to further external stimulation. Additional studies utilizing Biolog Phenotype Microarray technology indicated reduced energy production when cells were exposed to growth factors stimulating the PI3K/AKT/mTOR pathway, confirming the trend observed in the AKT phosphorylation test after stimulation. Furthermore, treatment with inhibitors of the PI3K/AKT/mTOR pathway rescued the normal energy response in the patients' cells. Collectively, these data demonstrate that disease-causing germline PIK3CA variants have a functional consequence, similar to mosaic variants in the PI3K/AKT/mTOR pathway.

Details

OriginalspracheEnglisch
Seiten (von - bis)1457-1465
Seitenumfang9
FachzeitschriftHuman molecular genetics
Jahrgang32
Ausgabenummer9
PublikationsstatusVeröffentlicht - 20 Apr. 2023
Peer-Review-StatusNein

Externe IDs

Scopus 85153410695
WOS 000912831000001

Schlagworte

Schlagwörter

  • Class I Phosphatidylinositol 3-Kinases/genetics, Germ Cells/metabolism, Mutation, Phosphatidylinositol 3-Kinases/genetics, Proto-Oncogene Proteins c-akt/genetics, TOR Serine-Threonine Kinases/genetics, Genetic Diseases, Inborn/genetics, Germ-Line Mutation, Phosphorylation, Pros, Mutations, Diagnosis

Bibliotheksschlagworte