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AKT is highly phosphorylated in pheochromocytomas but not in benign adrenocortical tumors

Martin Fassnacht1, Dirk Weismann, Silke Ebert

  • 1Department of Medicine, Endocrine and Diabetes Unit, University of Würzburg, 97080 Würzburg, Germany. Fassnacht_m@medizin.uni-wuerzburg.de

The Journal of Clinical Endocrinology and Metabolism
|April 28, 2005
PubMed
Abstract

Insights

Increased AKT activation is implicated in pheochromocytomas, a finding not observed in adrenocortical adenomas. This study investigated AKT

Area of Science:

  • Endocrinology
  • Oncology
  • Molecular Biology

Background:

  • Activation of AKT is a significant factor in numerous human cancers.
  • Pten gene heterozygous deletion in mice correlates with increased AKT activation and pheochromocytoma development.
  • Understanding AKT's role is crucial for diagnosing and treating adrenal tumors.

Purpose of the Study:

  • To investigate the role of AKT in the pathogenesis of pheochromocytomas.
  • To examine AKT's role in the development of adrenocortical tumors.

Main Methods:

  • Western blot analysis was used to quantify total AKT and phosphorylated AKT (pAKT) levels.
  • Immunohistochemistry was performed to assess AKT and pAKT expression in tumor tissues.
  • PTEN protein expression and loss of heterozygosity were analyzed in pheochromocytomas.

Main Results:

  • Total AKT expression was elevated in pheochromocytomas and adrenocortical carcinomas (ACC) compared to normal adrenals.
  • The pAKT/AKT ratio was significantly increased in pheochromocytomas but not in ACC or other adenomas.
  • No PTEN loss of heterozygosity or decreased PTEN protein was found in pheochromocytomas.

Conclusions:

  • Evidence suggests increased AKT activation in pheochromocytomas.
  • AKT activation is not significantly increased in common adrenocortical adenomas.
  • These findings differentiate the molecular pathways in pheochromocytomas versus adrenocortical adenomas.

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