Dynamic intracellular survivin in oral squamous cell carcinoma: underlying molecular mechanism and potential as an early prognostic marker

J Pathol. 2007 Apr;211(5):532-40. doi: 10.1002/path.2134.

Abstract

Survivin functions as an apoptosis inhibitor and a regulator of cell division in many tumours. The intracellular localization of survivin in tumours has been suggested as a prognostic marker. However, current reports are inconsistent and the underlying molecular mechanisms are not understood. The present study has examined the localization and prognostic value of nuclear and cytoplasmic survivin in the pre-therapeutic biopsies from 71 oral and oropharyngeal squamous carcinoma (OSCC) patients. Statistical analysis indicated that preferential nuclear versus cytoplasmic survivin correlated with favourable versus unfavourable disease outcome. Uni- and multi-variate analysis showed that in contrast to total survivin expression, the difference between nuclear and cytoplasmic survivin was a strong predictor for relapse-free survival (p=0.0003). As a potential underlying molecular mechanism, it is shown in OSCC cell lines that predominantly cytoplasmic survivin mediates protection against chemo- and radio-therapy-induced apoptosis. Importantly, the cytoplasmic localization of survivin is regulated by its nuclear export signal (NES), and export-deficient nuclear survivin is not cytoprotective. This study suggests that the difference between cytoplasmic and nuclear survivin is an indicator for survivin activity in tumour cells. Thus, this difference may serve as a predictive marker of outcome in OSCC patients undergoing multi-modality therapy. The pharmacogenetic interference with survivin's cytoplasmic localization is also to be pursued as a potential therapeutic strategy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology
  • Biomarkers, Tumor / analysis*
  • Carcinoma, Squamous Cell / chemistry*
  • Carcinoma, Squamous Cell / drug therapy
  • Carcinoma, Squamous Cell / radiotherapy
  • Cell Line, Tumor
  • Cell Nucleus / chemistry
  • Cysteine Proteinase Inhibitors / analysis*
  • Cytoplasm / chemistry
  • Head and Neck Neoplasms / chemistry*
  • Head and Neck Neoplasms / drug therapy
  • Head and Neck Neoplasms / radiotherapy
  • Humans
  • Immunohistochemistry / methods
  • Inhibitor of Apoptosis Proteins
  • Kaplan-Meier Estimate
  • Karyopherins / analysis
  • Microtubule-Associated Proteins / analysis*
  • Mouth Neoplasms / chemistry
  • Mouth Neoplasms / drug therapy
  • Mouth Neoplasms / radiotherapy
  • Neoplasm Proteins / analysis*
  • Nuclear Export Signals / physiology
  • Oropharyngeal Neoplasms / chemistry
  • Oropharyngeal Neoplasms / drug therapy
  • Oropharyngeal Neoplasms / radiotherapy
  • Prognosis
  • Receptors, Cytoplasmic and Nuclear / analysis
  • Survivin

Substances

  • BIRC5 protein, human
  • Biomarkers, Tumor
  • Cysteine Proteinase Inhibitors
  • Inhibitor of Apoptosis Proteins
  • Karyopherins
  • Microtubule-Associated Proteins
  • Neoplasm Proteins
  • Nuclear Export Signals
  • Receptors, Cytoplasmic and Nuclear
  • Survivin
  • exportin 1 protein