MDSCs in Breast Cancer: Metastasis, Lipid Metabolism, and Therapeutics.

Myeloid-derived suppressor cells (MDSC) are one of the major contributors to the immunosuppressive microenvironment of breast cancer. MDSCs have unique mechanisms for each breast cancer metastasis site, and lipid metabolism acts as an energy source necessary to perform the role of MDSCs. In addition, MDSCs show different characteristics depending on the breast cancer subtype. Currently, there is no clear understanding of MDSCs tailored to subtypes and metastatic sites in breast cancer. In this study, we reviewed the biology and function of MDSCs revealed in breast cancer, focusing on metastasis and lipid metabolism, and discussed treatments targeting MDSCs. Understanding MDSC properties and functions by breast cancer subtype and metastatic niche will be a prerequisite for taking the next step in subdividing patients with breast cancer and providing customized treatment.