Enzymatic activity of gluthatione S-transferase p and GST-P gene expression in tumor tissues of human thyroid gland

Expression of glutathione S-transferase P-form (GST-P) in tissues of diffuse-nodular goiter (DNG) and papillary thyroid cancer was studied. Enzymatic activity of GST-P was determined using ethacrynic acid substrate (19 patients) and the level of GST-P gene expression was determined by a multiplex PCR method (30 patients). It was shown that in DNG tissues, 2–4-fold increase in GST-P enzymatic activity was observed in 7 of 10 patients, whereas in cases with papillary thyroid cancer, this activity was 1,5–2-fold decreased in 8 of 10 patients. These results were confirmed by findings on the study of the gene expression level. Most patients with DNG had increased level of hGST-P gene in tumor tissue as compared to the normal limits (from 1,35 to 8 times). In cases of thyroid cancer, decrease in the level of hGST-P gene expression in thyroid tumor tissue was observed more frequently (at the average 1,5–3 times).