Abstract:To evaluate the expression and clinical significance of miR-320 in breast cancer. Methods The expression of miR-320 in 108 cases of breast cancer tissues and normal breast tissue were detected by RT -PCR, and analyzed the correlation between expression of miR -320 in breast cancer,pathological feature and clinical prognosis. Results The miR-320 expression levels of breast cancer tissue were significantly lower than normal breast tissue [ (0.58 ±0.17) vs (1.05 ±0.21) ] ( p< 0.05). The miR-320 expression level was closely correlated with TNM staging and lymph node metastasis (p < 0.05), but the miR-320 expression level was no correlated with age, menopause, pathological type, tumor size, C -erbB -2 expression, PCNA expression, PR expression and ER expression (p > 0.05). Conclusions miR-320 is lowly expression in the breast cancer, and its expression level is closely related with occurrence and development of breast cancer.