Over-expression of miR-675 in formalin-fixed paraffin-embedded (FFPE) tissues of breast cancer patients.

BACKGROUND Dysregulation of miR-675 has been found in a variety of solid tumors. MiR-675 has been suggested as having both oncogenic and tumor suppression properties in cancer. However, there is no evidence whether miR-675 is involved in breast cancer. The objective of this study was to evaluate the expression status of miR-675 and its clinical relevance in breast cancer patients. METHODS The expression level of miR-675 was detected in 100 breast cancer patients and 38 cancer-free controls using real-time quantitative PCR. The clinicopathological characteristics of miR-675 in breast cancer were also investigated. All statistical analyses were performed using SPSS 20.0. RESULTS The study showed that miR-675 was significantly up-regulated in breast cancer patients compared with controls (P < 0.01). There was no significant difference in age, lymph nodes stage, ER status and PR status between patients with and without miR-675 over-expression (P > 0.05). The frequency of miR-675 over-expression was higher in the patients of histological grade I-II than in others (50% versus 9%, P = 0.011). The expression level of miR-675 had a high correlation with miR-24/93/98/378 in breast cancer patients. CONCLUSIONS Taken together, our study demonstrated that miR-675 in formalin-fixed paraffin-embedded (FFPE) tissues might serve as a good source for biomarker discovery and breast cancer validation.