MiRNA affects the advancement of breast cancer by modulating the immune system's response

Breast cancer (BC), which is the most common tumor in women, has greatly endangered women's lives and health. Currently, patients with BC receive comprehensive treatments, including surgery, chemotherapy, radiotherapy, endocrine therapy, and targeted therapy. According to the latest research, the development of BC is closely related to the inflammatory immune response, and the immunogenicity of BC has steadily been recognized. As such, immunotherapy is one of the promising and anticipated forms of treatment for BC. The potential values of miRNA in the diagnosis and prognosis of BC have been established, and aberrant expression of associated miRNA can either facilitate or inhibit progression of BC. In the tumor immune microenvironment (TME), miRNAs are considered to be an essential molecular mechanism by which tumor cells interact with immunocytes and immunologic factors. Aberrant expression of miRNAs results in reprogramming of tumor cells actively, which may suppress the generation and activation of immunocytes and immunologic factors, avoid tumor cells apoptosis, and ultimately result in uncontrolled proliferation and deterioration. Therefore, through activating and regulating the immunocytes related to tumors and associated immunologic factors, miRNA can contribute to the advancement of BC. In this review, we assessed the function of miRNA and associated immune system components in regulating the advancement of BC, as well as the potential and viability of using miRNA in immunotherapy for BC.