eLife (Jul 2017)

Tsc2 disruption in mesenchymal progenitors results in tumors with vascular anomalies overexpressing Lgals3

  • Peter J Klover,
  • Rajesh L Thangapazham,
  • Jiro Kato,
  • Ji-an Wang,
  • Stasia A Anderson,
  • Victoria Hoffmann,
  • Wendy K Steagall,
  • Shaowei Li,
  • Elizabeth McCart,
  • Neera Nathan,
  • Joshua D Bernstock,
  • Matthew D Wilkerson,
  • Clifton L Dalgard,
  • Joel Moss,
  • Thomas N Darling

DOI
https://doi.org/10.7554/eLife.23202
Journal volume & issue
Vol. 6

Abstract

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Increased mTORC1 signaling from TSC1/TSC2 inactivation is found in cancer and causes tuberous sclerosis complex (TSC). The role of mesenchymal-derived cells in TSC tumorigenesis was investigated through disruption of Tsc2 in craniofacial and limb bud mesenchymal progenitors. Tsc2cKOPrrx1-cre mice had shortened lifespans and extensive hamartomas containing abnormal tortuous, dilated vessels prominent in the forelimbs. Abnormalities were blocked by the mTORC1 inhibitor sirolimus. A Tsc2/mTORC1 expression signature identified in Tsc2-deficient fibroblasts was also increased in bladder cancers with TSC1/TSC2 mutations in the TCGA database. Signature component Lgals3 encoding galectin-3 was increased in Tsc2-deficient cells and serum of Tsc2cKOPrrx1-cre mice. Galectin-3 was increased in TSC-related skin tumors, angiomyolipomas, and lymphangioleiomyomatosis with serum levels in patients with lymphangioleiomyomatosis correlating with impaired lung function and angiomyolipoma presence. Our results demonstrate Tsc2-deficient mesenchymal progenitors cause aberrant morphogenic signals, and identify an expression signature including Lgals3 relevant for human disease of TSC1/TSC2 inactivation and mTORC1 hyperactivity.

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