ROLE OF MIRNA-186-5P IN SUPPRESSING MIGRATION, INVASION, AND PROLIFERATION OF BREAST CANCER CELLS: IMPLICATIONS FOR CANCER MANAGEMENT IN ATHLETES

Abstract

Background: MicroRNA-186-5p (miR-186-5p) has been identified as under expressed in breast cancer tissues, with a corresponding overexpression of the SBEM protein, suggesting a potential regulatory role that could influence cancer progression. This study investigates the effect of miR-186-5p on the invasion, migration, and proliferation of breast cancer cells, with an emphasis on understanding its molecular mechanisms that could inform prevention strategies in athletic populations at risk. Methods: Breast cancer cell lines MDA-MB-231 and SUM159PT were transfected with either miR-186-5p inhibitors or mimics, and controls. Migration and invasion abilities were assessed using scratch and Transwell assays. Post-transfection, cells were treated with the PI3K pathway activator 740 Y-P to evaluate changes in SBEM and PI3K pathway-related proteins via Western blotting. The proliferation of cancer cells was further analyzed through monoclonal cell experiments. Results: Transfection with miR-186-5p mimics significantly inhibited the expression of SBEM, phosphorylated PI3K, phosphorylated AKT, and their downstream effectors, including MMP1, MMP3, MMP9, CyclinD1, PCNA, and CyclinB1, thereby reducing the proliferation, migration, and invasion of breast cancer cells. The addition of 740 Y-P highlighted that miR-186-5p primarily impacts SBEM expression without altering the PI3K pathway or cancer cell proliferation significantly. Conclusion: The study demonstrates that miR-186-5p serves as a critical suppressor of breast cancer progression by downregulating SBEM and modulating related oncogenic pathways. These findings suggest that enhancing the expression of miR-186-5p could be a viable strategy to inhibit breast cancer progression. For athletes, particularly female athletes who may be concerned about breast cancer risks associated with certain lifestyle or genetic factors, understanding and potentially modulating miR-186-5p levels could inform preventive measures that integrate routine health monitoring with their training regimes.