microRNA-21 was up-regulated in HER2 positive and Basal-like breast cancer types, while microRNA-206 was up-regulated in Luminal A and B types of breast cancer. microRNA-21 expression negatively correlated with the level of ER and PR but positively correlated with HER2 expression and tumor malignancy, while microRNA-206 showed the opposite trend.
Considered together, our study indicated that the overexpression of miR-206, miR-133a, and miR-27b might be potential biomarkers for prognosis and therapeutic strategies in breast cancer.
Expression of miR-206 is upregulated and expression of miR-145 is downregulated in breast cancer, which may have an impact on the prognosis of patients. miR-206 and miR-145 may serve as important indicators to predict prognosis of patients with breast cancer in the future.
MKL1 and SRF were further demonstrated to promote the expression of <i>IL11</i>, which is essential for miR-206's function in inhibiting both invasion and stemness of breast cancer.<b>Conclusions:</b> The identification of the miR-206/TWF1/MKL1-SRF/IL11 signaling pathway sheds lights on the understanding of breast cancer initiation and progression, unveils new therapeutic targets, and facilitates innovative drug development to control cancer and block metastasis.<i></i>.
Gene expression analyses of breast cancers expressing high levels of Myc indicated that low miR-206 expression and high MAP3K13 expression correlated with poor patient survival.
Quantitative RT-PCR was conducted to evaluate miR-206 expression in 77 breast cancer samples to determine the associations between miR-206 levels and both lymph node status and Cx43 expression.
Two SNPs, miR-34b/34c (rs4938723, HR = 0.57 (95 % CI = 0.37-0.89, p value = 0.01)) and miR-206 (rs6920648, HR = 0.77 (95 % CI = 0.61-0.97, p value = 0.02)), provided evidence of association with breast cancer survival.
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.
Thus, miR-206 might be a novel candidate for morphogenesis during the initiation of mammary gland formation and the regulation of genes related to mammary gland development and breast cancer.