miRNA-411 acts as a potential tumor suppressor miRNA via the downregulation of specificity protein 1 in breast cancer.

The expression and functions of microRNA (miR)-411 have been investigated in several types of cancer. However, until now, miR-411 in human breast cancer has not been examined. The present study investigated the expression, biological functions and molecular mechanisms of miR-411 in human breast cancer, discussing whether it offers potential as a therapeutic biomarker for breast cancer in the future. The expression levels of miR-411 in human breast cancer tissues and cells were measured using reverse transcription-quantitative polymerase chain reaction analysis. Following transfection with miR-411 mimics, an MTT assay, cell migration and invasion assay, western blot analysis and luciferase assay were performed in human breast cancer cell lines. According to the results, it was found that miR-411 was significantly downregulated in breast cancer, and associated with lymph node metastasis and histological grade. Additionally, it was observed that miR-411 suppressed cell growth, migration and invasion in the breast cancer cells. The present study also provided the first evidence, to the best of our knowledge, that miR-411 was likely to directly target specificity protein 1 in breast cancer. These findings indicated that miR-411 may be used a therapeutic biomarker for the treatment of breast cancer in the future.