Monoclonal antibodies to glutathione S‐Transferase π–immunohistochemical analysis of human tissues and cancers

Mouse monoclonal antibodies (MAb) have been generated against the anionic isozyme of human glutathione S-transferase (GST pi). MAb AGST I can inhibit 50-70% of GST pi enzymatic activity and reacts with a 3-dimensional epitope which includes a putative glutathione binding site on GST pi. A sandwich enzyme-immunoassay established using MAb AGST I and a polyclonal antibody displayed a sensitivity of 0.5 ng/ml. Immunohistochemical analysis of human tissues demonstrated marked increases in GST pi levels in cancers of the brain, cervix, endometrium, colon, rectum and testis and in fibro- and chondrosarcomas.