Serum trace element levels and activity of enzymes associated with oxidative stress in endometriosis and endometrial cancer.

Endometriosis and endometrial cancer are closely related with oxidative stress. However, the direct relationship between copper and zinc levels and oxidative stress in the extracellular and intracellular space remains unclear. The presented study is focused on determination of serum Zn and Cu levels, glutathione concentration and enzyme activity in three groups: patients diagnosed with endometrial cancer (EC), patients diagnosed with endometriosis (EM) and a healthy control group. Spectrophotometric determination of trace elements revealed that levels of zinc and copper were lower in blood plasma of patients with endometriosis as compared with the other groups; however, there were no significant differences in the Cu/Zn ratio. Furthermore, significantly increased blood serum glutathione levels were detected in both EM and EC groups compared to the control group. While the activity of superoxide dismutase (SOD) was similar across the studied groups, we observed differences in the activity of other enzymes associated with oxidative stress, including glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), between the control group and the EM and EC patients. Additionally, analysis of gene expression based on free circulating mRNA indicated significant differences in the expression of SOD isoenzymes between the patient groups and the control group; expression of GPx isoenzymes was also altered. Our results may have potential application in diagnostics as well as monitoring of endometriosis and endometrial cancer.