The Role of Tumor Associated Macrophages in the Tumor Microenvironment: Mechanism and Functions

During tumor progression, several types of inflammatory cells are recruited into the tumor site, where they participate in tumor-associated inflammation, such as fibroblasts, granulocytes, lymphocytes and macrophages. Macrophages infiltrating into the tumor microenvironment are termed tumorassociated macrophages (TAMs). In response to multiple stimuli, macrophages undergo recruitment and polarization, and play an important role in further tumor development. In this article, we present a review of the mechanism of macrophage' recruitment, and the role that TAMs play in promoting immunosuppression, tumor progress and metastasis, as well as chemoresistance and future therapeutic strategies.