Glutathione S-transferase activity as an early marker for malignant tumors of corpus uteri.

Glutathione (GSH) concentrations and glutathione S-transferase (GST) activities were determined in 30 paired malignant human corpus uteri tumor samples and in samples of adjacent normal tissues. For GSH concentrations no difference was found between normal (126.0 +/- 52.4 nmol/mg protein) and tumor tissues (110.1 +/- 46.4 nmol/min/mg protein; p = 0.219). The GST activities were significantly higher in tumor tissues (322.4 +/- 135.54 nmol/min/mg protein) than in corresponding normal tissues (224.6 +/- 95.64 nmol/min/mg protein; p = 0.005). This activities were independent on the pathohistological and clinical factors, except for positive lymphovascular invasion and myometrial invasion (over 50%), where significantly lower GST activities were found. For normal tissues the positive correlation between GSH concentrations and GST activities was found (correlation coefficient = 0.50, p = 0.005), but not for tumor tissue (correlation coefficient = 0.20, p = 0.281). The prognosis of patients (according to the well established prognostic factors, such as tumor type, myometrial invasion and grades) who had lower GSH concentration and GST activity in normal tissue was similar to those with higher GSH concentration and GST activity. In conclusion, higher GST activities found in tumor of corpus uteri suggest, that GST activity could be used as a tumor marker for the early stages of these malignant tumors.