Table 1

Induction of CYP1 mRNAs by DIM and TCDD

DoseFold inductionExpression level (% GAPDH)Ratio
DIM10 μmol/L89214.14.40.03020.34.6
DIM30 μmol/L3104911.015.50.07154.43.5
TCDD50 pmol/L182716.39.10.10231.13.4
TCDD100 pmol/L54415410.127.20.21950.21.8
TCDD10 nmol/L1,8191,03716.9911.48840.9

NOTE: RNA isolated from MCF-7 cells treated for 18 h with the indicated doses of DIM or TCDD was analyzed by real-time PCR to assess the level of CYP1A1, CYP1A2, CYP1B1, and GAPDH RNA. The fold induction was calculated as the ratio of induced CYP1 RNA to basal CYP1 RNA after GAPDH normalization. The expression level was calculated as (CYP1 RNA level/GAPDH RNA level) × 100. The ratio 1B1/1A1 was calculated as (CYP1B1 RNA level/CYP1A1 RNA level) × 100. The results represent an average of two independent samples.