Prognostic significance of sphingosine kinase 2 expression in non-small cell lung cancer

Tumour Biol. 2014 Jan;35(1):363-8. doi: 10.1007/s13277-013-1051-1. Epub 2013 Aug 7.

Abstract

Sphingosine kinase 2 (SphK2) as a conserved lipid kinase has not been thoroughly elucidated in non-small cell lung cancer (NSCLC). The aim of the present study was to evaluate the expression of SphK2 in NSCLC tissues and to determine its correlation with clinicopathologic characteristics and its impact on patient prognosis. We assessed the expression of SphK2 and proliferating cell nuclear antigen (PCNA) (as a proliferative index) by immunohistochemistry in 180 NSCLC patient's formalin-fixed paraffin-embedded tissue blocks. Relationship between the expression of SphK2 and PCNA and various clinicopathological features in these patients was evaluated. We detected that expression of SphK2 was gradually upregulated from normal, metaplasia/dysplasia tissues to NSCLC tissues. At the same time, PCNA expression followed a similar pattern. Statistical analysis showed that expression of SphK2 in NSCLC tissues was strongly associated with PCNA expression, histology grade, live vaccine strain invasion, lymph node status, clinical stage, tumors size, and histology type. Patients with SphK2 overexpression in their tissues had lower overall survival (OS) and disease-free survival (DFS) rates than those with low SphK2 expression. Using uni- and multivariate analysis, we found that SphK2 overexpression was an independent prognostic factor for both OS and DFS. The expression of SphK2 parallels the progression of NSCLC, and SphK2 overexpression may represent a novel and potentially independent biomarker for the prognosis of patients with NSCLC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Female
  • Gene Expression
  • Humans
  • Immunohistochemistry
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology
  • Male
  • Middle Aged
  • Neoplasm Grading
  • Neoplasm Staging
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Prognosis
  • Proliferating Cell Nuclear Antigen / genetics
  • Proliferating Cell Nuclear Antigen / metabolism
  • Risk Factors
  • Tumor Burden

Substances

  • Proliferating Cell Nuclear Antigen
  • Phosphotransferases (Alcohol Group Acceptor)
  • sphingosine kinase