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.
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 cancerpatients 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.
Authors: G Cadoni; S Boccia; L Petrelli; P Di Giannantonio; D Arzani; A Giorgio; E De Feo; M Pandolfini; P Gallì; G Paludetti; G Ricciardi Journal: Acta Otorhinolaryngol Ital Date: 2012-02 Impact factor: 2.124