Epithelial cell adhesion molecule promotes metastasis and multidrug resistance of breast cancer through induction of epithelial-mesenchymal transition / 中国药理学通报

ABSTRACT

Aim: To investigate the effect of epithelial cell adhesion molecule (EpCAM) on metastasis and multidrug resistance of breast cancer and its mechanism. Methods Immunohistochemical staining was employed to detect the expression of EpCAM in adjacent non-tumor tissues (ANTTs) and breast cancer tissues. siRNA was applied to knock down EpCAM expression in MDA-MB-231 cells. Transwell assay was used to detect the invasion and migration ability of breast cancer cells. Western blot analysis was performed to determine the protein expression of EpCAM, epithelial mesenchymal transition (EMT) markers E-cadherin, N-cadherin and vimentin, breast cancer resistance protein (BCRP), and β-catenin. Results EpCAM immunoreactivity was consistently stronger in primary breast cancer tissues and even higher in metastatic lesions than that in ANTTs. The expression of EpCAM was significantly upregulated in triple negative breast cancer MDA-MB-231 cells. EpCAM knockdown using siRNA decreased the invasion and migration ability and BCRP expression, and partially reversed the EMT phenotypes of MDA-MB-231 cells, β-catenin expression was upregulated in MDA-MB-231 cells. ICG-001, a specific Wnt/β-catenin pathway inhibitor, downregulated the expression levels of EpCAM, N-cadherin, and vimentin in MDA-MB-231 cells. Conclusions EpCAM could promote metastasis and drug resistance of breast cancer through the induction of EMT, which is related to the Wnt/β-catenin signaling pathway.