Glutathione and glutathione S-transferases in human squamous cell carcinomas of the larynx and GSTM1 dependent risk

Anticancer Res. Jan-Feb 1998;18(1A):107-11.

Abstract

Background: The aim of the present study was to establish the risk of squamous cell carcinoma (SCC) of the larynx associated with the congenital absence of glutathione S-transferase M1 (GSTM1), and to describe the expression of the isoenzymes GSTA1/2, GSTP1-1, and GSTM1 and glutathione (GSH) content in healthy and tumoral larynx tissue.

Material and methods: Blood samples from 160 SCC male patients and 158 controls were phenotyped for GSTM1 by ELISA. Using 37 paired samples (normal and tumour specimens) from cancer patients we carried out a descriptive study of enzyme activity by ELISA (GSTs) and Ellman's as say (GSH) RESULTS: GSTM1 null phenotype was more common in the SCC group than in controls (OR 1.9, CIs 1.18-3.05, p = 0.004). Total GST activity was higher in tumour samples than in matched healthy tissue (2.2-fold, p-0.00001), being largely determined by GSTP1-1 (1.9-fold increased in malignant tissue; p = 0.0003). The GSH content was also significantly higher in SCC than in normal mucosa (1.9-fold, p = 0.0007).

Conclusions: We confirmed the GSTM1-dependent risk for larynx cancer among smokers. The overexpression of the GST/GSH system in tumours reported here indicates their possible role in chemoresistance to pharmacological therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Squamous Cell / enzymology
  • Carcinoma, Squamous Cell / metabolism*
  • Glutathione / metabolism*
  • Glutathione Transferase / metabolism*
  • Humans
  • Isoenzymes / metabolism*
  • Laryngeal Neoplasms / enzymology
  • Laryngeal Neoplasms / metabolism*
  • Male
  • Risk Factors

Substances

  • Isoenzymes
  • Glutathione Transferase
  • Glutathione