Glutathione and glutathione S-transferases as early markers for ovarian carcinomas: case series

To determine the activity of glutathione (GSH) and concentrations of glutathione S-transferases (GST), urokinase type plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI-1), and to evaluate their diagnostic and prognostic value and possible correlation with clinical and histopathological prognostic factors for ovarian carcinomas.

The concentrations of GSH, uPA, PAI-1, and activity of GST were analyzed in 35 tissue samples taken from 10 normal ovaries, 10 benign, 10 primary malignant, and 5 metastatic ovarian tumors. The GSH level and GST activity were determined by spectrophotometric methods, and uPA and PAI-1 concentrations by ELISA commercial kits.

GSH concentrations were significantly higher in primary malignant (126.3+/-12.8 nmol/mg protein) and metastatic (160.5+/-24.3 nmol/mg protein) ovarian tumor specimens than in normal ovarian tissue (48.9+/-8.1 nmol/mg protein, p<0.003 for both carcinoma groups) or benign ovarian tumor samples (35.2+/-5.0 nmol/mg protein, p=0.001). The GST activity was significantly higher in primary malignant (245.8+/-22.7 nmol/min/mg protein) and metastatic (303.7+/-48.8 nmol/min/mg protein) ovarian tumor tissues than in benign tumor specimens (105.9+/-16.2 nmol/min/mg protein, p<0.004 for both carcinoma groups) or normal ovarian tissue samples (133.2+/-32.0 nmol/min/mg protein, p<0.044 for both carcinoma groups). There were no statistical differences in uPA and PAI-1 concentrations between normal, benign, and malignant tumor samples. Concentrations of GSH, uPA and PAI-1, and activity of GST were independent from histopathological and clinical prognostic factors.

Increased GSH concentration and GST activity found in primary malignant and metastatic ovarian tumor samples were independent of histopathological and clinical prognostic factors, suggesting that they could be early markers for ovarian carcinomas.