Estradiol and mTORC2 cooperate to enhance prostaglandin biosynthesis and tumorigenesis in TSC2-deficient LAM cells

J Exp Med. 2014 Jan 13;211(1):15-28. doi: 10.1084/jem.20131080. Epub 2014 Jan 6.

Abstract

Lymphangioleiomyomatosis (LAM) is a progressive neoplastic disorder that leads to lung destruction and respiratory failure primarily in women. LAM is typically caused by tuberous sclerosis complex 2 (TSC2) mutations resulting in mTORC1 activation in proliferative smooth muscle-like cells in the lung. The female predominance of LAM suggests that estradiol contributes to disease development. Metabolomic profiling identified an estradiol-enhanced prostaglandin biosynthesis signature in Tsc2-deficient (TSC(-)) cells, both in vitro and in vivo. Estradiol increased the expression of cyclooxygenase-2 (COX-2), a rate-limiting enzyme in prostaglandin biosynthesis, which was also increased at baseline in TSC-deficient cells and was not affected by rapamycin treatment. However, both Torin 1 treatment and Rictor knockdown led to reduced COX-2 expression and phospho-Akt-S473. Prostaglandin production was also increased in TSC-deficient cells. In preclinical models, both Celecoxib and aspirin reduced tumor development. LAM patients had significantly higher serum prostaglandin levels than healthy women. 15-epi-lipoxin-A4 was identified in exhaled breath condensate from LAM subjects and was increased by aspirin treatment, indicative of functional COX-2 expression in the LAM airway. In vitro, 15-epi-lipoxin-A4 reduced the proliferation of LAM patient-derived cells in a dose-dependent manner. Targeting COX-2 and prostaglandin pathways may have therapeutic value in LAM and TSC-related diseases, and possibly in other conditions associated with mTOR hyperactivation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analysis of Variance
  • Animals
  • Aspirin / pharmacology
  • Breath Tests
  • Carcinogenesis / metabolism*
  • Carrier Proteins / genetics
  • Cell Proliferation / drug effects
  • Cyclooxygenase 2 / metabolism
  • Estradiol / metabolism*
  • Female
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / physiology*
  • Gene Knockdown Techniques
  • Humans
  • Immunoblotting
  • Immunohistochemistry
  • Lipoxins / analysis
  • Lymphangioleiomyomatosis / metabolism*
  • Mechanistic Target of Rapamycin Complex 2
  • Metabolomics
  • Mice
  • Mice, SCID
  • Microscopy, Confocal
  • Multiprotein Complexes / metabolism*
  • Naphthyridines / pharmacology
  • Prostaglandins / biosynthesis*
  • Prostaglandins / blood
  • Rapamycin-Insensitive Companion of mTOR Protein
  • Real-Time Polymerase Chain Reaction
  • TOR Serine-Threonine Kinases / metabolism*
  • Tuberous Sclerosis Complex 2 Protein
  • Tumor Suppressor Proteins / deficiency

Substances

  • 1-(4-(4-propionylpiperazin-1-yl)-3-(trifluoromethyl)phenyl)-9-(quinolin-3-yl)benzo(h)(1,6)naphthyridin-2(1H)-one
  • Carrier Proteins
  • Lipoxins
  • Multiprotein Complexes
  • Naphthyridines
  • Prostaglandins
  • RICTOR protein, human
  • Rapamycin-Insensitive Companion of mTOR Protein
  • TSC2 protein, human
  • Tsc2 protein, mouse
  • Tuberous Sclerosis Complex 2 Protein
  • Tumor Suppressor Proteins
  • lipoxin A4
  • Estradiol
  • Cyclooxygenase 2
  • Mechanistic Target of Rapamycin Complex 2
  • TOR Serine-Threonine Kinases
  • Aspirin