Circulating miR-21 and miR-155 as potential noninvasive biomarkers in Iranian Azeri patients with breast carcinoma

Background: Breast cancer (BC) is the most common cause of cancer-related mortality among women. Despite recent advances in diagnosis and prognosis of breast carcinomas, noninvasive biomarkers have been poorly identified. We evaluated the biomarker potential of miR-21 and miR-155 in tissue and plasma specimens of Iranian Azeri patients. Materials and Methods: Tumor specimens, paired nontumoral adjacent tissues, and matched plasma samples were collected from a number of thirty Iranian Azeri women with breast carcinoma. Plasma of healthy women was used as the control. The relative expression of miR-21 and miR-155 was measured by real-time polymerase chain reaction. Results: Our data revealed that the expression levels of miR-21 and miR-155 in tumor tissues are significantly higher than paired nontumoral adjacent specimens (P < 0.05). Furthermore, receiver operating characteristic (ROC) curve analysis of samples showed the area under the ROC curve of 0.81 for miR-21 and area of 0.83 for miR-155. In addition, statistical analysis showed that miR-21 and miR-155 RNAs are significantly detected in the plasma of BC patients compared to healthy specimens (P < 0.05). Circulating miRNAs yielded area under the ROC curve of 0.99 for miR-21 and 0.92 for miR-155. Conclusion: Our data showed that miR-21 and miR-155 oncomiRs can be considered as noninvasive biomarkers for monitoring breast carcinomas. However, further investigations are needed to confirm the use of these noncoding RNAs in pathology.