Circulating miRNA-containing Exosomes as potential biomarkers for diagnosis and monitoring of breast cancer

Breast cancer is most prevalent cancer in women and responsible for a great number of cancer related deaths in women around the world. Traditional diagnosis methods for breast cancer like mammography limited to require a minimum size of tumor cells. Therefore, not all of breast cancers can be detect in their early stages, when they are amendable to treatment. specific molecular biomarkers can be used to detection of early stages cancers. Exosomes are extracellular vesicles that secreted by a variety of cells and they are contain some components like miRNAs. Exosomes from different type of cells contain parent-specific component. Application of exosomal miRNAs for breast cancer may be differ in diagnostic, subtype prediction and drug resistances. Mir-101, mir-372, mir-21 and mir-1246 increase in the serum of breast cancer patients. mir-210 upregulated and mir-19a and mir-29c downregulated in breast cancer that metastases to brain. mir-10b, mir-9 and mir-939 began to upregulation in tumor cells and increasing in patient’s serum when the cancer change to metastasis form. mir-231 that secreted by TAMs promote cell invasion in breast cancer. mir-273 related to ER and PR negative subtype of breast cancer. Mir-210 contained exosomes that secreted from tumor cells in hypoxia condition led to angiogenesis in tumor site. Mir- 222 make drug resistance in tumor cells for Adriamycin and mir-221/mir-222 make resistance to tamoxifen. Therefore, these researches reveals that exosomal miRNAs has this potential to become biomarkers of different condition of breast cancer. Some clinical trial in this field is underway to assess these molecules. Some challenges should be resolved in this field, for example, source of miRNA as well as a universal and repetitive simple method for purification of exosomal miRNAs is need

Keywords:

Breast cancer , Exosomes , miRNA , Biomarker