COX-2 and PGE2-dependent immunomodulation in breast cancer

COX-derived prostanoids play multiple roles in inflammation and cancer. This review highlights research examining COX-2 and PGE2-dependent regulation of immune cell polarization and function within the tumor microenvironment, particularly as it pertains to breast cancer. Appreciating PGE2-mediated immunomodulation is important in understanding how tumors evade immune surveillance by re-educating infiltrating inflammatory and immune cells to support tumorigenesis. Elucidation of the multiple and complex influences exerted by tumor stromal components may lead to targeted therapies in breast and other cancers that restrain microenvironmental permissiveness and maintain natural defenses against malignancies.

► In this review, we discuss PGE2 immunomodulation of the tumor microenvironment.
► We particularly emphasize macrophage, MDSC, and Treg-based immunosuppression.
► Understanding PGE2-derived immunosuppression may lead to targeted cancer therapies.