FIGURE 2.

Inability to bind to DNA prevents AHR from inducing IL6 synergy. A, MCF-7 cells were transfected with control or AHR targeting siRNA oligonucleotides, with or without pcDNA3 vector. The vectors used were control (lane C), WT cDNA synthetic hAHR-pcDNA3, or AHR-GS-pcDNA3. 24 h after transfection, the cells were serum-starved for 18 h, whole cell extracts were prepared, and protein levels of AHR and p23 (control) were assessed by immunoblot. B and C, MCF-7 cells were electroporated, plated into 6-well dishes, and then serum-starved before being treated for 2 h with vehicle, 10 ng/ml IL1β, 1 nm TCDD, or TCDD+IL1β. The relative IL6 and CYP1A1 mRNA levels were determined by quantitative real time PCR. WT, wild type. CV, control vector.