Advances of Exosomal miRNAs in Breast Cancer Progression and Diagnosis

Abstract

Breast cancer is one of the most commonly diagnosed malignancies and the leading cause of cancer death in women worldwide. Although many factors associated with breast cancer have been identified, the definite etiology of breast cancer is still unclear. In addition, early diagnosis of breast cancer remains challenging. Exosomes are membrane-bound nanovesicles secreted by most types of cells and contain a series of biologically important molecules, such as lipids, proteins, and miRNAs, etc. Emerging evidence shows that exosomes can affect the status of cells by transmitting substances and messages among cells and are involved in various physiological and pathological processes. In breast cancer, exosomes play a significant role in breast tumorigenesis and progression through transfer miRNAs which can be potential biomarkers for early diagnosis of breast cancer. This review discusses the potential utility of exosomal miRNAs in breast cancer progression such as tumorigenesis, metastasis, immune regulation and drug resistance, and further in breast cancer diagnosis.

Keywords: breast cancer; diagnosis; exosome; miRNAs; potential biomarkers.

Figure 1

Breast cancer-related exosomal miRNAs in breast cancer progression.

Figure 2

Detection approaches for breast cancer-related exosomal miRNA analysis. (A) RT-qPCR method for exosomal miRNA analysis, the length of miRNA was increased by stem-loop (left) or poly (A) tailing (right) method [112]. (B) Flow chart for miRNA sequencing. The length of miRNA was increased by an adapter at both 3′ and 5′ sides. (C) Molecular beacon for single (left) [110] and multiple (right) [113] exosomal miRNA analysis. (D) Schematic representation of the electrochemical platform for exosomal miRNA detection [114].