Induction and expression of GST-Pi foci in the liver of Cyclophosphamide-administered rats.

Anticancer drug Cyclophosphamide (CY) is metabolized to phosphoramide mustard and acrolein by the hepatic P450 enzymes. GST-Pi is a biochemical feature which occurs in carcinogen induced preneoplastic foci and it plays an important role in the detoxification pathway of acrolein metabolism. Administration of CY induces GST-Pi positive single cells and foci expression in rat liver and these can be considered as precursors of preneoplastic foci leading to hepatocarcinogenesis. The expression of GST-Pi in CY-treated rats on different days of treatment was confirmed by immunohistochemistry, immunoblot, RT-PCR and by ELISA. We also advocate that epigenetic mechanism could be accounted for the GST-Pi induction in the hepatocytes of CY-treated rats.