Fig. 6.

LA CS induces binding of c-Fos/c-Jun to endogenous Pgp promoter. Cross-linked chromatin was isolated from untreated (control) and LA CS-treated Caco-2 cells subsequent to formaldehyde treatment. Chromatin immunoprecipitation assays were performed with c-Fos or c-Jun antibody. Coimmunoprecipitated DNA as template and primers were used to amplify the Pgp promoter region (see materials and methods). A: amplified PCR products of expected size resolved on 1% agarose gel. B: quantification of binding of AP1 cis elements of Pgp promoter with c-Fos or c-Jun immunoprecipitates (IP) in the presence and absence of LA CS utilizing primers spanning the AP1 binding sites (primer 1, −172/+1 bp) or ∼0.8 kb away from the AP1 binding sites (primer 2, −973/+801 bp). Results represent 3 separate experiments. *P < 0.05 vs. control.