Effect of N,N'-dinitrosopiperazine on in vitro expression of human cytochrome P450 2E1

Abstract

Objective: To establish an in vitro heterogeneous expression model of human CYP2E1 (hCYP2E1) cDNA and investigate the effect of the chemical carcinogenic N, N'-dinitrosopiperazine (DNP) on the expression of CYP2E1.

Methods: Exogenous hCYP2E1 was introduced into the mouse derived NIH3T3 cells using the lipofectamine transfection technique. Integration of exogenous hCYP2E1 gene was identified by PCR and Southern blot. After treatment with various concentration of ethanol and DNP on the transfected NIH3T3 cell cultures, RT-PCR and Western blot was applied to detect the expression level of CYP2E1.

Results: Two cell clones with integration and stable expression of exogenous hCYP2E1 were obtained and designated as NIH3T3-2E1-A4 and NIH3T3-2E1-A8 respectively. The expression of both hCYP2E1 mRNA and protein products was promoted after either ethanol or DNP treatment.

Conclusion: The results suggested that the promoted expression of hCYP2E1 induced by DNP and /or ethanol is due to enhanced transcription. The mechanism of DNP carcinogenes is might be related to this in situ activated metabolism by CYP2E1.