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Spontaneous Murine Model of Anaplastic Thyroid Cancer
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Activation of the mTOR pathway in primary medullary thyroid carcinoma and lymph node metastases

Anna Tamburrino1, Alfredo A Molinolo, Paolo Salerno

  • 1Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA.

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|July 4, 2012
PubMed
Abstract

Insights

The AKT/mTOR pathway is activated in medullary thyroid carcinoma (MTC), especially in lymph node metastases. Targeting this pathway may offer effective treatment for advanced MTC patients.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cancer Research

Background:

  • Medullary thyroid carcinoma (MTC) molecular pathogenesis is key for targeted therapy development.
  • Understanding signaling pathways involved in MTC progression is crucial for advanced disease treatment.

Purpose of the Study:

  • To investigate the activation status of RAS/MEK/ERK and PI3K/AKT/mTOR pathways in MTC.
  • To determine the role of the mTOR pathway in MTC cell behavior and tumorigenicity.

Main Methods:

  • Immunohistochemistry was used to assess protein phosphorylation in 53 MTC tissues and 21 matched lymph node metastases (LNMs).
  • Cell viability, motility, and tumorigenicity were measured in MTC cells following mTOR pathway inhibition.
  • Staining intensity was graded using an S score based on positive cell percentage.

Main Results:

  • High phosphorylation of ribosomal protein S6 (pS6), a downstream mTOR target, was observed in 96% of primary MTCs and 96% of LNMs.
  • AKT activation was present in 79% of MTC cases, correlating with pS6 activation.
  • LNMs showed significantly higher pS6 positivity compared to matched primary MTCs (P = 0.024).
  • mTOR blockade reduced MTC cell viability, motility, and tumorigenicity.

Conclusions:

  • The AKT/mTOR pathway is activated in MTC, with heightened activity in LNMs.
  • This pathway supports malignant characteristics in MTC cells.
  • Targeting the mTOR pathway presents a potential therapeutic strategy for advanced MTC.

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