Abstract
Several studies have shown that miR-215-5p acts as a tumor suppressor in certain cancers, but its role in the progression and metastasis of breast carcinoma remains incompletely understood. Herein, we prove that miR-215-5p is substantially down-expressed in breast carcinoma as compared with nontumor tissue. Up-regulation of miR-215-5p inhibits the aggressive abilities of breast carcinoma cells in vitro. We performed luciferase reporter tests to show that SRY-Box 9 (Sox9) is the target of miR-215-5p; as predicted, Sox9 depletion replicates the suppressive effects of miR-215-5p on breast carcinoma cells, and overexpression of Sox9 rescues the effects of miR-215-5p on breast cancer cell progression. In addition, a xenograft model assay was used to reveal that miR-215-5p inhibits breast cancer cell growth and metastatic potential in vivo. Overall, these results imply that miRNA-215-5p suppresses the aggressiveness of breast cancer cells through targeting Sox9.