Expression and localisation of Akt-1, Akt-2 and Akt-3 correlate with clinical outcome of prostate cancer patients

Br J Cancer. 2006 Jun 19;94(12):1906-12. doi: 10.1038/sj.bjc.6603184. Epub 2006 May 23.

Abstract

We investigated the correlation between the expression and localisation of Akt-1, Akt-2, Akt-3, phospho-Akt proteins and the clinicopathological parameters in 63 prostate cancer specimens. More than 60% of cancerous tissues overexpressed Akt-1, Akt-2 or Akt-3. Cytoplasmic Akt-1 expression was correlated with a higher risk of postoperative prostate-specific antigen (PSA) recurrence and shorter PSA recurrence interval. Cytoplasmic Akt-2 did not show any significant correlation with clinicopathological parameters predicting outcomes. Cytoplasmic Akt-3 was associated with hormone-refractory disease progression and extracapsular invasion. Nuclear Akt-1 and Akt-2 expression were correlated with favourable outcome parameters such as absence of lymph node and perineural invasion. Kaplan-Meier analysis and Cox regression model also showed that Akt-1 and Akt-2, but not Akt-3 or phospho-Akt was associated with a significantly higher risk of PSA recurrence. In contrast, nuclear Akt-1 was significantly associated with a lower risk of PSA recurrence. Multivariate analysis revealed that clinical stage, Gleason score and the combined cytoplasmic nuclear Akt-1 marker in cancerous tissues were significant independent prognostic factors of PSA recurrence. This is the first report demonstrating in patients with prostate cancer and the particular role of Akt-1 isoform expression as a prognostic marker depending of its localisation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers, Tumor / analysis
  • Blotting, Western
  • Humans
  • Immunohistochemistry
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Prognosis
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology*
  • Protein Isoforms / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Tissue Array Analysis

Substances

  • Biomarkers, Tumor
  • Protein Isoforms
  • Proto-Oncogene Proteins c-akt
  • Prostate-Specific Antigen