Decreased expression of microRNA-206 in breast cancer and its association with disease characteristics and patient survival.

OBJECTIVES

MicroRNA-206 (miR-206) is downregulated in many human malignancies, which correlates with tumour progression. This study characterized the contribution of miR-206 to the initiation and progression of human breast cancer.

METHODS

Consecutive primary breast cancer patients who received radical resection were enrolled. Breast cancer tissue samples were obtained during surgery. MiR-206 levels in matched pairs of cancer tissue and normal adjacent tissue (NAT) samples were examined using quantitative reverse transcription-polymerase chain reaction. The relationship between miR-206 levels and clinicopathological characteristics and overall survival was also investigated.

RESULTS

In 128 patients with breast cancer, miR-206 was downregulated in 119 (93%) tumour tissue compared with their matched NAT samples. Decreased miR-206 was significantly associated with advanced clinical stage and lymph node metastasis. Univariate and multivariate Cox proportional hazard regression analysis revealed that a low miR-206 level was an unfavourable prognostic factor for overall survival, in patients with breast cancer.

CONCLUSIONS

This study indicated that miR-206 may be a good candidate as a novel prognostic indicator in breast cancer patients.