Figure 4.

Over-expression of MUC1 reduces CagA/β-catenin co-immunoprecipitation. AGS cells were transfected with the pcDNA empty vector or the pMUC1 expression plasmid. At 24 h post-transfection, the cells were untreated or were treated with H. pylori (Hp) at an MOI of 100. At 24 h post-infection, the cells were washed and cell lysates were immunoprecipitated with antibodies to β-catenin (A) or CagA (B). Immunoprecipitated proteins were resolved by SDS-PAGE, transferred to PVDF membranes, and processed for immunoblotting with antibodies to CagA (A) or β-catenin (B). To control for to control for protein loading and transfer, blots were stripped and reprobed with the same antibody used for immunoprecipitation. Molecular weight markers are indicated on the left in kilodaltons (kDa). (C) Densitometry of the blots in (A). (D) Densitometry of the blots in (B). Each bar represents the mean ± SEM value of the density of the CagA band normalized to the β-catenin band [from (A)], or the β-catenin band normalized to the CagA band [from (B)], in Hp-treated cells (n = 3). (E) Increased MUC1 expression in AGS cells transfected with the pMUC1 plasmid. The results are representative of two experiments.