The Association of miR-451 and miR-21 in Plasma with Lymph Node Metastases in Breast Cancer

BACKGROUND AND OBJECTIVE: The expression of some circulating microRNAs (miRNAs) in biological fluids of healthy individuals is different from cancerous patients. circulating miRNAs are a new class of cancer biomarkers because of their high stability and sensitivity, ease of measurement and specificity due to their correlation with various cancer states. According to the miR-451 and miR-21 functions in the metastasis of some cancers, the aim of this study was to investigate the differences of expression levels of miR-451 and miR-21 in the plasma of breast cancer (BC) patients with and without lymph nodes metastasis (LNM). METHODS: In this descriptive-analytical study, blood samples were collected from 47 women with BC and 24 healthy women with mammography confirmation. The presence/or absence of LNM was recognized from patients' medical records. The expression levels of miR-451 and miR-21 in the plasma, were investigated using Real-Time PCR. FINDINGS: The median of expression of miR-451 in BC patients with LNM and without LNM was 1.739 and 3.187, respectively, and its expression in lymph node metastatic patients decreased 0.444 folds in comparison with non-metastatic patients (p=0.031). The median of expression of miR-21 in patients with LNM and in non-metastatic lymph nodes patients was 5.922 and 2.157, respectively, and its expression in metastatic status was 2 folds higher than non-metastatic (p=0.029). CONCLUSION: The results of this study indicated that decreased miR-451 and increased miR-21 expression in plasma of BC patients was associated with LNM status