An expressional system of human cytochrome P-450 CYP1A1 gene transcription.

AIM: To explore an expressional system of human cytochrome P-450 CYP1A1 (CYP1A1) gene transcription. METHODS: The plasmid pMC 6.3 K containing human CYP1A1 promoter was transiently transfected into Hep G2 cells. The expression of chloramphenical acetyltransferase (CAT) reporter gene was detected by ELISA. RESULTS: Both the CAT expression and CYP1A1 activity increased with the concentrations of beta-naphthoflavone from 2.5 to 10 mumol.L-1. At 10 mumol.L-1 of beta-naphthoflavone, the levels of CAT and CYP1A1 were 94-fold and 2.8-fold those of the corresponding control, respectively. Using this method, the study of 8 glucosinolates with various side chains on the induction of CYP1A1 gene transcription showed that none of the parent glucosinolates increased CAT expression, whereas the breakdown products of indol-3-yl-methyl glucosinolate (glucobrassicin), rather than indole-3-carbinol, increased the CAT expression. CONCLUSION: The CYP1A1 gene transcriptional system was more reliable and sensitive.