PMID- 26312899
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20160301
LR  - 20220129
IS  - 1474-547X (Electronic)
IS  - 0140-6736 (Linking)
VI  - 385 Suppl 1
DP  - 2015 Feb 26
TI  - Phosphoinositide 3-kinase-related overgrowth: cellular phenotype and future 
      therapeutic options.
PG  - S77
LID - S0140-6736(15)60392-0 [pii]
LID - 10.1016/S0140-6736(15)60392-0 [doi]
AB  - BACKGROUND: Somatic activating mutations in PIK3CA, which encodes the p110alpha 
      catalytic subunit of phosphoinositide-3-kinase (PI3K) are frequently found in 
      cancers and have been identified in a spectrum of mosaic overgrowth disorders 
      ranging from isolated digit enlargement to more extensive overgrowth of the body, 
      brain, or vasculature. We aimed to study affected dermal fibroblasts with a view 
      to inform therapeutic studies, and to observe cancer-associated mutations in 
      isolation. METHODS: We measured PIP3 concentrations in dermal fibroblasts with 
      endogenous PIK3CA mutations and in wild type fibroblasts using mass spectrometry, 
      and we measured downstream signalling events with ELISA and immunoblotting. 
      Cellular proliferation was evaluated with 5-bromo-2'-deoxyuridine incorporation, 
      and cell size assessed by fluorescence-activated cell sorting (FACS). Glycolysis 
      and mitochondrial tests were performed with an extracellular flux analyser 
      (Seahorse Bioscience, Billerica, MA, USA), and mitochondrial potential was 
      measured by FACS-based JC1 staining. Experiments were repeated after exposure to 
      5 nmol everolimus for 72 h. FINDINGS: Mutant fibroblasts had two times higher 
      basal PIP3 concentrations than wild-type fibroblasts (p=0.0017), with concomitant 
      AKT and p70S6 activation downstream. The rate of cellular proliferation was 
      higher in mutant cells under low serum conditions, but median cell size was not 
      statistically different. Glycolytic capacity was similar between mutant and wild 
      type fibroblasts, but subtle differences in mitochondrial function were detected 
      with blunted responses to uncoupling agents and reduced membrane potentials. 
      Treatment with everolimus reversed aberrant AKT(ser473) and p70S6 signalling, 
      slowed cellular proliferation, and reversed mitochondrial abnormalities, but was 
      associated, paradoxically, with increases in PIP3 concentrations. INTERPRETATION: 
      These experiments demonstrate activation of the PI3K-AKT pathway in affected 
      fibroblasts with increased proliferation, but no hypertrophy. Moreover, we 
      identified changes in mitochondrial function in keeping with the known propensity 
      of AKT to modulate elements of the Warburg effect. These results suggest that 
      inhibitors of the mammalian target of rapamycin (mTOR) might be beneficial, but 
      these inhibitors will require formal evaluation in clinical trials. More targeted 
      therapy with p110alpha inhibitors is an enticing future option. FUNDING: Wellcome 
      Trust, Sackler Fund, National Instititute for Health Research.
CI  - Copyright (c) 2015 Elsevier Ltd. All rights reserved.
FAU - Parker, Victoria E R
AU  - Parker VE
AD  - Institute of Metabolic Science, Metabolic Research Laboratories, University of 
      Cambridge, Cambridge, UK. Electronic address: verp2@medschl.cam.ac.uk.
FAU - Knox, Rachel G
AU  - Knox RG
AD  - Institute of Metabolic Science, Metabolic Research Laboratories, University of 
      Cambridge, Cambridge, UK.
FAU - Zhang, Qifeng
AU  - Zhang Q
AD  - Babraham Institute, Cambridge, UK.
FAU - Wakelam, Michael J O
AU  - Wakelam MJ
AD  - Babraham Institute, Cambridge, UK.
FAU - Semple, Robert K
AU  - Semple RK
AD  - Institute of Metabolic Science, Metabolic Research Laboratories, University of 
      Cambridge, Cambridge, UK.
LA  - eng
GR  - 098498/WT_/Wellcome Trust/United Kingdom
GR  - BB/H024824/1/BB_/Biotechnology and Biological Sciences Research Council/United 
      Kingdom
GR  - BBS/E/B/000C0415/BB_/Biotechnology and Biological Sciences Research 
      Council/United Kingdom
GR  - BBS/E/B/000C0419/BB_/Biotechnology and Biological Sciences Research 
      Council/United Kingdom
PT  - Journal Article
PL  - England
TA  - Lancet
JT  - Lancet (London, England)
JID - 2985213R
EDAT- 2015/08/28 06:00
MHDA- 2015/08/28 06:01
CRDT- 2015/08/28 06:00
PHST- 2015/08/28 06:00 [entrez]
PHST- 2015/08/28 06:00 [pubmed]
PHST- 2015/08/28 06:01 [medline]
AID - S0140-6736(15)60392-0 [pii]
AID - 10.1016/S0140-6736(15)60392-0 [doi]
PST - ppublish
SO  - Lancet. 2015 Feb 26;385 Suppl 1:S77. doi: 10.1016/S0140-6736(15)60392-0.