Overexpression of Aquaporin-1 Promotes Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties via Wnt/β-Catenin Signaling Pathway in Advanced Breast Cancer Cells.

Tumor metastasis and the persistence of cancer stem cells (CSCs) are the main factors contributing to tumor malignancy, particularly in breast cancer. Uncovering the critical molecular mechanisms and therapeutic targets is essential for addressing this challenge. The present study revealed that aquaporin-1 (AQP1) was highly expressed in breast cancer and was closely associated with poor patient prognosis. AQP1 overexpression significantly enhanced multiple cellular processes in breast cancer cells, including cell proliferation, migration, invasion, spheroid formation, and three-dimensional (3D) spheroid invasion. Moreover, AQP1 activated the Wnt/β-catenin signaling pathway, and promoted the expression of epithelial-mesenchymal transition (EMT)-related markers (N-cadherin and vimentin) and CSC markers (SOX2 and c-Myc). Furthermore, small hairpin (sh)RNA-mediated downregulation of β-catenin confirmed the mechanism by which AQP1 promoted EMT and CSC properties through the activation of the Wnt/β-catenin signaling pathway. In conclusion, the present study elucidated the molecular mechanism through which AQP1 advanced breast cancer progression via the Wnt/β-catenin signaling pathway, providing insights into the mechanisms underlying breast cancer progression and offering valuable implications for developing novel therapeutic strategies.