miR-3607-5p served as a prognostic biomarker for triple-negative breast cancer and mediated bone metastasis by modulating LEF1

Background Triple-negative breast cancer (TNBC) is of high invasiveness and malignancy. Recurrence and metastasis are major challenges for the clinical management of TNBC. Identifying predictive biomarkers is of great significance to improve the clinical prognosis of TNBC. Objectives This study focused on miR-3607-5p in the development and prognosis of TNBC, aiming to explore a promising biomarker for TNBC. Materials and methods There were 124 patients diagnosed with TNBC included, and their tumor tissues and adjacent normal tissues were collected. Tissue miR-3607-5p was detected, and its association with patients’ clinicopathological features and 5-year recurrence-free survival was evaluated. In vitro, the effect and mechanisms of miR-3607-5p on TNBC cell proliferation, metastatic potential, and angiogenesis were investigated. Results Decreasing miR-3607-5p in TNBC tumor tissues was significantly associated with advanced TNM stage, occurrence of lymph node metastasis, bone metastasis, and Ki67 levels of TNBC patients. Lower miR-3607-5p levels indicate poorer 5-year recurrence-free survival of TNBC patients and were identified as an independent prognostic indicator. Overexpressing miR-3607-5p significantly suppressed cell proliferation, migration, and invasion of TNBC cells and inhibited the expression of angiogenesis-related molecules. LEF1 was predicted as the downstream target of miR-3607-5p, which mediates its regulatory effects on TNBC cells. Conclusion miR-3607-5p could indicate TNBC severity and predict patients’ prognosis. miR-3607-5p can be considered a promising therapeutic target for TNBC.