LAUSR

OBJECTIVE Breast cancer is one of the most common malignant and highly heterogeneous tumors in women. MicroRNAs (miRNAs), such as miR-1246, play important roles in various types of malignant cancers, including triple-negative breast cancer (TNBC). However, the biological role of miR-1246 in TNBC has not yet been fully elucidated. In this study, we studied the role of miR-1246 in the occurrence and development of TNBC and its mechanism of action. METHODS Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays were performed to observe the effects of miR-1246 on TNBC cell proliferation, migration, and invasion, respectively. The expression of epithelial-mesenchymal transition (EMT) markers was detected by western blotting. Dual luciferase reporter assays were performed to determine whether DYRK1A is a novel target of miR-1246. In addition, an immunoprecipitation experiment was performed to verify the binding of DYRK1A to PGRN. Rescue experiments were performed to determine whether DYRK1A is a novel target of miR-1246 and whether miR-1246 suppresses the metastasis of breast cancer cells by targeting the DYRK1A/PGRN axis to prevent the epithelial-mesenchymal transition. RESULTS Our results show that miR‑1246 suppresses the proliferation, migration, and invasion of TNBC cells, DYRK1A is a novel target of miR-1246 and Importin-8 mediated miR-1246 nuclear translocation. MiR‑1246 plays a suppressive role in the regulation of the EMT of TNBC cells by targeting DYRK1A. DYRK1A mediates the metastasis of triple-negative breast cancer via activation of the EMT. We identified PGRN as a novel DYRK1A-interacting protein. Overexpression of PGRN and DYRK1A promoted cell proliferation and migration of TNBC, but this effect was reversed by co-expression of miR-1246 mimics.DYRK1A and PGRN act together to regulate the occurrence and development of breast cancer through miR-1246. CONCLUSION MiR-1246 suppresses the metastasis of breast cancer cells by targeting the DYRK1A/PGRN axis and preventing the epithelial-mesenchymal transition. The MiR-1246/DYRK1A/PGRN axis regulates TNBC progression, suggesting that MiR-1246 could be promising therapeutic targets for the treatment of TNBC.