Stimulation of the Estrogen Axis Induces Epithelial-Mesenchymal Transition in Human Salivary Cancer cells.

BACKGROUND Salivary gland cancer is a common type of head and neck cancer characterized by occasional deep invasion and lung metastasis. The precise role of sex steroid hormones in salivary gland cancer is unclear. To address this issue, we investigated whether the estrogen axis modulates salivary adenocarcinoma (SAC) and whether hormone therapy can be an effective treatment. MATERIALS AND METHODS The estrogen receptor (ER) was overexpressed in HSG human SAC cells that lack endogenous ER and the cells were treated with and without 17β-estradiol (E2). RESULTS E2 enhanced malignant phenotypes. Moreover, E2 treatment reduced E-cadherin expression, while increasing that of N-cadherin, vimentin, and inhibitor of differentiation 1 proteins that are associated with the epithelial-mesenchymal transition. Cell invasion was enhanced through activation of matrix metalloproteinase-9. CONCLUSION These results indicate that hormone therapy used in breast cancer may also be effective for ER-positive SAC.