Differential Expression of Serum Exosomal miRNAs in Breast Cancer Patients and Healthy Controls

Breast cancer has become as a serious public health concern worldwide. Breast cancer cells release exosomes into the circulatory system, which are easily accessible for further analysis like cancer diagnosis. In this study, we aimed to investigate expression of circulating exosomal miRNAs (miRs) in the serum of individuals with breast cancer and healthy controls. Exosomes were collected from serum samples using a commercial kit and characterized by scanning electron microscopy (SEM) and flow cytometry analysis. Expression of miRs such as miR-21, miR-155, miR-182, miR-373, and miR-126 were evaluated by real-time PCR. The result showed that the expression level of exosomal miR-21, miR-155, miR-182, and miR-373 in the serum of breast cancer patients was higher than of those controls (P<0.05). However, expression of miR-126 did not change between breast cancer and control individuals (P > 0.05). Our results showed a different miRs expression pattern between breast cancer and healthy samples, supposing potential biomarkers for breast cancer. Further studies focusing on these miRs are required to confirm our findings.