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Rare PIK3CA hotspot mutations in carcinomas of the biliary tract

Marc-Oliver Riener1, Marion Bawohl, Pierre-Alain Clavien

  • 1Department of Pathology, Institute of Surgical Pathology, University Hospital Zurich, 8091 Zurich, Switzerland.

Genes, Chromosomes & Cancer
|January 9, 2008
PubMed

Insights

Somatic PIK3CA mutations are rare in biliary tract and liver cancers but can activate the PI3K/AKT pathway. This pathway activation is common in these cancers, suggesting its role in disease progression.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • Somatic mutations in PIK3CA are common in many cancers.
  • PIK3CA encodes a key enzyme in the PI3K pathway.
  • PIK3CA mutations in biliary tract and gallbladder cancers were previously unreported.

Purpose of the Study:

  • To investigate PIK3CA hotspot mutations in biliary tract and liver carcinomas.
  • To assess PI3K pathway activation in these cancers.

Main Methods:

  • Analysis of 118 carcinomas (cholangiocarcinomas, gallbladder, hepatocellular carcinomas) for PIK3CA mutations using PCR and DNA sequencing.
  • Immunohistochemistry for downstream PI3K pathway targets (eIF4-E, p-4E-BP1) on tissue microarrays.

Main Results:

  • PIK3CA mutations were found in intrahepatic cholangiocarcinoma (9%), gallbladder carcinoma (4%), and hepatocellular carcinoma (2%).
  • PI3K pathway activation, indicated by eIF4-E expression and 4E-BP1 phosphorylation, was frequently observed across all analyzed hepato-biliary carcinomas.

Conclusions:

  • Somatic PIK3CA mutations are infrequent in biliary tract and liver cancers.
  • The PI3K/AKT pathway is frequently activated in these cancers, suggesting a role beyond PIK3CA mutations.

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