GLUTATHIONE CONCENTRATIONS AND GLUTATHIONE-S-TRANSFERASE ACTIVITY IN HUMAN COLONIC NEOPLASMS

Tissue concentrations of glutathione (GSH) and the activity of glutath ione S-transferases (GST) are relevant to the inactivation of a variet y of xenobiotics including carcinogens and anti-neoplastic drugs. In t his study, GSH concentrations and GST activity were determined in 25 a denomatous polyps removed at colonoscopy, and in cancer and uninvolved 'normal' mucosa from 58 operative specimens containing colon cancer. We also examined the relationship between GSH concentrations, GST acti vity and rates of cell proliferation as assessed by flow cytometry. Co ncentrations of GSH were significantly higher in adenomas (P = 0.001) and cancer (P = 0.001) than in uninvolved mucosa while GST activity wa s significantly higher in cancer (P =0.007). There was a positive rela tionship between GSH concentrations and GST activity in adenomas (P = 0.001) but not in uninvolved mucosa (P = 0.06) or cancer (P = 0.4). Co ncentrations of GSH and GST activity were independent of results from flow cytometry. The higher concentrations of GSH in colonic neoplasms and the raised activity of GST in cancer may contribute to their resis tance to anti-neoplastic drugs.