Endotoxin Triggers Tumor Initiation Events in Nontumorigenic Breast Epithelial Cells and Enhances Invasion-Related Phenotype in Pretumorigenic and Tumorigenic Breast Epithelial Cells

Figure 6

Long-term endotoxin treatment alters β-catenin localization in 3D cultures of human breast epithelial S1 cells. (a) Representative S1 acini immunostained for β-catenin (red) and counterstained with Hoechst (blue). The upper lane shows a control untreated S1 acinus with undisrupted monolayered lumen and apicolateral β-catenin localization. The lower lane shows an S1 acinus following ET treatment at 10 μg/ml revealing relocalization of β-catenin from the apicolateral to the lateral and basolateral domain while maintaining undisrupted monolayered lumen. (b) Quantification data of β-catenin localization shows significant redistribution of β-catenin from the apicolateral to the basolateral domain in S1 acini with monolayered lumen after long-term ET treatment at 10 μg/ml. Localization of β-catenin was evaluated under confocal microscopy. One hundred acini with monolayered lumen from every replicate were visualized, and each acinus was scored for polarity based on the β-catenin (red) localization as apicolateral versus basolateral. Each bar represents triplicate analyses of mean ± SD. compared to the untreated control.

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