INCREASE IN PLACENTAL GLUTATHIONE-S-TRANSFERASE IN HUMAN OVAL EPITHELIAL DYSPLASTIC LESIONS AND SQUAMOUS-CELL CARCINOMAS

This study investigated the immunohistochemical expression of human pl acental glutathione S-transferase (GST-pi) in the epithelium of oral p remalignant and malignant lesions. Epithelial lining of normal oral mu cosa, hyperplastic lesions and oral epithelium exhibiting mild dysplas ia showed weak to moderate GST-pi staining. Moderate epithelial dyspla sia revealed an increased antibody content while severe dysplasia, car cinoma-in-situ (CIS) and squamous cell carcinoma (SCC) demonstrated ma rkedly increased antibody binding. The GST-pi staining was evident mai nly in the cytoplasm. Severe dysplasia, CIS and SCC were also characte rized by areas of cells with intensive nuclear GST-pi staining. These findings support the hypothesis that GST-pi plays a role in human oral carcinogenesis and may be used as a tumor marker for human oral prema lignant and malignant lesions.