Evidence for different expression profiles for c-Met, EGFR, PTEN and the mTOR pathway in low and high grade endometrial carcinomas in a cohort of consecutive women. Occurrence of PIK3CA and K-Ras mutations and microsatellite instability

Histol Histopathol. 2014 Nov;29(11):1455-66. doi: 10.14670/HH-29.1455. Epub 2014 May 8.

Abstract

Molecular and genetic investigations in endometrial carcinogenesis may have prognostic and therapeutic implications. We studied the expression of EGFR, c-Met, PTEN and the mTOR signalling pathway (phospho-AKT/phospho-mTOR/phospho-RPS6) in 69 consecutive tumours and 16 tissue microarrays. We also analysed PIK3CA, K-Ras mutations and microsatellite instability (MSI). We distinguished two groups: group 1 (grade 1 and 2 endometrioid cancers) and group 2 (grade 3 endometrioid and type II clear and serous cell cancers). We hypothesised that these histological groups might have different features. We found that a) survival was higher in group 1 with less aggressive tumours (P⟨0.03); b) EGFR (P=0.01), PTEN and the AKT/mTOR/RPS6 signalling pathway were increased in group 1 versus group 2 (P=0.05 for phospho-mTOR); c) conversely, c-Met was higher (P⟨0.03) in group 2 than in group 1; d) In group 1, EGFR was correlated with c-Met, phospho-mTOR, phospho-RPS6 and the global activity of the phospho-AKT/phospho-mTOR/phospho-RPS6 pathway. In group 2, EGFR was correlated only with the phospho-AKT/phospho-mTOR/phospho-RPS6 pathway, whereas c-Met was correlated with PTEN; e) survival was higher for tumours with more than 50% PTEN-positive cells; f) K-RAS and PIK3CA mutations occurred in 10-12% of the available tumours and MSI in 40.4%, with a loss of MLH1 and PMS2 expression. Our results for endometrial cancers provide the first evidence for a difference in status between groups 1 and 2. The patients may benefit from different targeted treatments, anti-EGFR agents and rapamycin derivatives (anti-mTOR) for group 1 and an anti c-MET/ligand complex for group 2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma / genetics
  • Carcinoma / metabolism*
  • Class I Phosphatidylinositol 3-Kinases
  • DNA Mutational Analysis
  • Endometrial Neoplasms / genetics
  • Endometrial Neoplasms / metabolism*
  • ErbB Receptors / genetics*
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic
  • Genes, ras
  • Humans
  • Immunohistochemistry
  • Ki-67 Antigen / metabolism
  • Ligands
  • Microsatellite Instability*
  • Microsatellite Repeats / genetics
  • Middle Aged
  • Mutation
  • PTEN Phosphohydrolase / genetics*
  • Phosphatidylinositol 3-Kinases / genetics
  • Proto-Oncogene Proteins c-met / genetics*
  • Retrospective Studies
  • TOR Serine-Threonine Kinases / genetics*

Substances

  • Ki-67 Antigen
  • Ligands
  • MTOR protein, human
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human
  • EGFR protein, human
  • ErbB Receptors
  • Proto-Oncogene Proteins c-met
  • TOR Serine-Threonine Kinases
  • PTEN Phosphohydrolase
  • PTEN protein, human