Immunohistochemistry of omega class glutathione S-transferase in human tissues.

Omega class glutathione transferase (GSTO) has been recently described in a number of mammalian species. We used immunohistochemistry to determine the cellular and tissue distribution of GSTO1-1 in humans. Expression of GSTO1-1 was abundant in a wide range of normal tissues, particularly liver, macrophages, glial cells, and endocrine cells. We also found nuclear staining in several types of cells, including glial cells, myoepithelial cells of the breast, neuroendocrine cells of colon, fetal myocytes, hepatocytes, biliary epithelium, ductal epithelium of the pancreas, Hoffbauer cells of the placenta, and follicular and C-cells of the thyroid. These observations and the known activity of GSTO1-1 suggest biological functions that are not shared with other GSTs.