RESUMEN
OBJECTIVES: MicroRNA-200 family (miR-200f) has been consistently reported to be deregulated and modulate the metastatic process in multiple cancers. In the present study, we detected the expression of miR-200f in breast cancer (BC) tissue and explored its relationships with clinicopathological characteristics, especially with lymph node metastasis. METHODS: Expression levels of miR-200a, miR-200b, miR-200c, miR-141, and miR-429 in 99 pairs of BC tissues and adjacent normal tissues were measured by real-time quantitative PCR. The correlation between miR-200f level and multiple clinicopathological factors was then examined by Mann-Whitney test, ANOVA, and operating characteristic (ROC) analysis. RESULTS: All members of the miR-200f were down-regulated in BC tissue compared with that in normal adjacent tissue; miR-200a, miR-200b, and miR-200c were highly decreased (p < 0.05), while the differences of miR-141 and miR-429 between patients and the control group were not statistically significant. Furthermore, all five members were found to be distinctly decreased with the incidence of lymph node metastasis (p < 0.05); When the patients were divided into three groups according to the number of lymph node metastasis (0; 1-3; ≥4), a gradual decrease of miR-200f expression was observed with the increasing number of lymph node metastasis; ROC revealed that miR-200b can differentiate patients with lymph node metastasis from those without lymph node metastasis. CONCLUSION: These observations imply that the down-regulation of miR-200f in human BC is associated with an invasive phenotype, and miR-200b may be useful to estimate the likelihood of the presence of pathologically positive lymph nodes.