Glutathione S-transferase in human endometrium: quantitation and interindividual variability in isoform content

The goals of the present study were to determine whether human endometrium contains glutathione S-transferases (GSTs), to identify the isoforms present (if any) and to assess the causes of any intersubject variability which was observed.

Hysterectomy patients (n = 32, 13 with endometrial carcinoma) were examined in the core study. The ability of cytosol from these endometria to conjugate 1-chloro-2,4-dinitrobenzene was measured. Additional studies with chemical inhibitors and monoclonal antibodies to GSTpi were also performed.

The pattern of inhibition caused by ethacrynic acid and cibacron blue strongly suggests substantial interindividual variability in type (alpha and pi dominant) and amount ( approximately 10-fold) of this important group of enzymes. Significantly lower GST activity was seen in cancer patients who were smokers when compared with all other subjects (p < 0.05).

There are substantial interindividual differences in the GST content of human endometrium. Furthermore, lower GST activity in tissues from endometrial carcinoma patients with a history of smoking may have contributed to the neoplastic transformation of this tissue.