Claudin 1 Promotes Migration and Increases Sensitivity to Tamoxifen and Anticancer Drugs in Luminal-like Human Breast Cancer Cells MCF7

Downregulation of claudin 1, a critical tight junction protein, has been correlated with increased invasiveness in breast cancer. However, recent studies suggest that claudin 1 contributes to the progression of some molecular subtypes of breast cancer. In this study, claudin 1 promotes migration in luminal-like MCF7 human breast cancer cells and increases their sensitivity to tamoxifen, etoposide, and cisplatin. We also observed an inverse relationship between upregulation of claudin 1 and TGF beta. Collectively, our results suggest that claudin 1 has the potential to be used as a predictive marker for treatment efficacy for specific breast cancer patient subgroups.