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Suppression of Peutz-Jeghers polyposis by targeting mammalian target of rapamycin signaling

Chongjuan Wei1, Christopher I Amos, Nianxiang Zhang

  • 1Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|February 19, 2008
PubMed

Insights

Rapamycin treatment significantly reduced polyposis in a mouse model of Peutz-Jeghers syndrome (PJS). This mTOR inhibitor suppressed tumor burden, indicating potential as a targeted therapy for PJS.

Area of Science:

  • Gastroenterology
  • Oncology
  • Molecular Biology

Background:

  • Peutz-Jeghers syndrome (PJS) is a genetic disorder linked to LKB1 mutations, characterized by gastrointestinal hamartomas and increased cancer risk.
  • Hyperactivation of mammalian target of rapamycin (mTOR) signaling is implicated in PJS pathogenesis.
  • Lkb1+/- mice serve as a valuable model for studying human PJS.

Purpose of the Study:

  • To investigate the efficacy of mTOR inhibition using rapamycin in suppressing polyposis in Lkb1+/- mice.
  • To evaluate rapamycin's potential as a targeted therapy for Peutz-Jeghers syndrome.

Main Methods:

  • Lkb1+/- mice with established polyposis were treated with rapamycin (2 mg/kg/d) for 2 months.
  • Efficacy was assessed by measuring polyp size and overall tumor burden.
  • mTOR signaling inhibition was confirmed by evaluating S6 phosphorylation levels via immunostaining.

Main Results:

  • Rapamycin treatment led to a significant decrease in both mean and total tumor burden compared to controls (P = 0.023).
  • Rapamycin effectively reduced the burden of large polyps (> 8 mm).
  • A decrease in phosphorylated S6 levels within polyps correlated with rapamycin treatment.

Conclusions:

  • Rapamycin demonstrates significant efficacy in suppressing Peutz-Jeghers polyposis in a relevant mouse model.
  • These findings suggest that rapamycin and its analogues hold promise as a novel targeted therapy for PJS.
Abstract

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