DIFFERENTIAL EXPRESSION OF CYTOCHROME P4502E1 (CYP2E1) IN MORRIS HEPATOMAS AND LIVERS OF TUMOR-BEARING RATS

The objective of this investigation was to determine if the decrease o f cytochrome P4502E1 (CYP2E1) in hepatomas is related to the tumor gro wth rate. There was a significant correlation between N-nitrosodimethy lamine (NDMA) demethylase activities and CYP2E1 protein levels in rat liver and hepatomas. The levels of NDMA demethylase activities and CYP 2E1 protein content were lower in hepatomas than in the corresponding host livers. NDMA demethylase activities and CYP2E1 protein levels wer e greater in hepatomas of slow and intermediate growth rate than in fa st growing hepatomas. A similar trend was also observed with CYP2E1 mR NA levels. The results demonstrated an inverse relationship between gr owth rate of rat hepatomas and the expression of CYP2E1.