miR-499a-5P confers oncogenic roles in breast cancer by targeting SOX6

Abstract

Abstract Breast cancer is the most frequent malignancy in females worldwide, causing more than 680,000 deaths in 2020. Dysregulated microRNAs have been linked etiologically with breast cancer, controlling a wide range of cellular pathways. Dual luciferase reporter assay was used to confirm the link between miR-499a-5p and SOX6. Studies including proliferation, migration and invasion assay were carried out to investigated functional roles. Animal model was introduced for in vivo investigation. We found high expression level of miR-499a-5p in breast cancer tissues which associated with worse survival. Overexpression of miR-499a-5p played oncogenic role by promoting cell growth and invasiveness in breast cancer cells. SOX6 was identified as the potential target of miR-499a-5p by silico prediction, which was confirmed by dual luciferase reporter assay. Further study confirmed a tumor suppressive role of SOX6 in breast cancer. Subcutaneous administration of breast cancer cells with ectopic miR-499a-5p expression led to larger tumor volume in mice. Taken together, for the first time, we identified a direct link between miR-499a-5p and its down-stream target SOX6, revealing their functionality, which would provide novel insight into the mechanism of breast cancer. Our finding indicating a promising diagnostic and therapeutic op-tion towards this malignant disease.