Strong expression of glutathione S-transferase placental form in early preneoplastic lesions and decrease with progression in hamster buccal pouch carcinogenesis

The objective of this work was to investigate the expression of glutathione S-transferase placental form (GST-P) in 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Lesions were classified histopathologically into four categories, simple hyperplasia, papillary and nodular (PN) hyperplasia, papilloma and squamous cell carcinoma (SCC). Respective mean percentage GST-P positive areas were 81.6±7.3%, 76.1±7.3%, 25.8±4.9% and 1.9±1.2%, with significant (P<0.001) differences confirmed between each of the lesions. These results indicate that GST-P is a useful positive marker for neoplastic lesions and that a decreased expression occurs with progression so that it may be predictive of future development of malignancy.